Andrea Kavanaugh

John C Tedesco
email: tedesco@vt.edu

Kumbirai Madondo
email: kmadondo@vt.edu

John C Tedesco²

Social Media vs. Traditional Internet Use for Community Involvement: Toward Broadening Participation

Keywords: Digital government, community engagement, civic participation, Internet, social media

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Education consistently has been the main predictor of political and civic engagement in offline and traditional Internet contexts (i.e., email and web browsing). Prior research on the use of traditional Internet for civic purposes suggests that the 'more educated, extroverted, and activist' type of individuals (i.e., opinion leaders) continued to be more engaged in civic affairs regardless of offline or online context. However, the use of social media for civic purposes may be less strongly correlated with education, as well as activism and extroversion. Social media (e.g., social network sites like Facebook or MySpace, blogs and micro-blogs like Twitter, and photo and video sharing sites like Flickr and YouTube) are able to leverage offline social networks online to enable information and idea sharing among trusted sources about civic issues and concerns.

We report here findings from a 2012 survey of residents in the geographic community of Blacksburg, Virginia and surrounding Montgomery County in southwest Virginia. Located in the foothills of the Allegheny Mountains in Appalachia, Blacksburg and Montgomery County are home to the land grant university, Virginia Tech, and the community computer network known as the Blacksburg Electronic Village (BEV) that established Internet access for the public in this geographic area in 1993. The Blacksburg Electronic Village (BEV) was an early leader in community computer networking simply by making the Internet accessible and by training and supporting users, including residents, government, businesses, community groups, public schools and libraries. Since those early Internet years, though, the vast majority of Americans (79%) have adopted the Internet, as have most organizations [START_REF]Trend Data: Internet Penetration[END_REF]. Our findings from earlier studies of Internet effects on community involvement for Blacksburg and environs have been replicated in similar middle class US localities, including PrairieNet in Champaign-Urbana, Illinois, the Seattle Community Network in Seattle, Washington, and Three Rivers FreeNet in Pittsburgh, Pennsylvania [START_REF] Kavanaugh | Talking in lists: The consequences of computer mediated communication on communities[END_REF]. Most US cities currently have a variety of locally oriented content online for community organizations, government, and neighborhoods [START_REF] Hampton | Neighbors Online. Pew Internet & American Life Project[END_REF]. Blacksburg and environs are still somewhat ahead of other communities on Internet penetration rates, but we are confident that findings from our investigation will continue to generalize to similar middle class towns and mixed rural areas. To the extent that Blacksburg is advanced in its use of social software [START_REF] Ogilvyone | Social Media Sells! Ogilvy & Mather[END_REF] the results of our work will continue to contribute to community computing and political participation research.

Theoretical Background and Justification

Political participation theories, and most research findings on influences of civic and political participation, generally find that education is the main predictor of participation, albeit sometimes in association with political efficacy, information access, group membership and community attachment [START_REF] Gonzalez-Bailon | The structure of political discussion networks: A model for the analysis of online deliberation[END_REF][START_REF] Jacobs | Talking Together: Public Deliberation and Political Participation in America[END_REF][START_REF] Kim | News, talk, opinion, participation: the part played by conversation in deliberative democracy[END_REF][START_REF] Schudson | Why conversation is not the soul of democracy[END_REF][START_REF] Carroll | Community collective efficacy: Structure and consequences of perceived capacities in the Blacksburg Electronic Village[END_REF][START_REF] Carroll | Social and Civic Participation in a Community Network[END_REF][START_REF] Hampton | Grieving for lost network: Collective action in a wired suburb[END_REF][START_REF] Kavanaugh | When everyone's wired: Use of the Internet for networked communities[END_REF]. Kavanaugh and colleagues modeled the influence of education, extroversion, and age (as external variables), and the influence of local group membership, staying informed, community collective efficacy and activism (as mediating variables) on the use of traditional Internet for civic purposes [START_REF] Zúñiga | Digital Democracy: Reimagining Pathways to Political Participation[END_REF]. Well-educated, extroverted, informed activists with multiple group memberships (that is, essentially opinion leaders) become more involved in local community issues when they go online. Thus, traditional Internet has tended to reinforce the engagement of people who were already engaged.

In addition to education, as noted above, other variables that influence political participation include political efficacy, information access, group membership and community attachment. Along with extroversion, these variables describe opinion leaders, the 10-15% of any population who are early innovation adopters and informal (and sometimes formal) sources for advice and recommendations to others in their social network and beyond. While opinion leaders are political active, not all political activists are opinion leaders.

A number of studies on social networks have argued that political discussion networks play a crucial role in the democratic process because they give citizens the opportunity to engage in political talk and access to conflicting ideas [START_REF] Godara | The Efficacy of Knowledge Sharing in Centralized and Self-organizing Online Communities: A Comparative Analysis of Weblogs vs Centralized Discussion Forums[END_REF][START_REF] Kavanaugh | Models of local government blogging: Design trade-offs in civic engagement[END_REF]. Some scholars have emphasized the importance of political talk as a precursor to political participation [START_REF] Kavanaugh | When opinion leaders blog: New forms of citizen interaction[END_REF][START_REF] Tauro | Deliberation in the Wild: A Visualization Tool for Blog Discovery and Citizen-to-Citizen Participation[END_REF]; although others have disputed this emphasis [START_REF] Kraut | Internet paradox revisited[END_REF]. Since social media enable a rich type of interpersonal dialogue and deliberation among members of a social network, online political discussion networks can be wider and deeper than the networks generated by other types of discussion [START_REF] Kavanaugh | Models of local government blogging: Design trade-offs in civic engagement[END_REF].

We have collected and analyzed household surveys for almost two decades (1993-2012) in Blacksburg and environs. Our results have showed a clear trend indicating that traditional Internet use (i.e., email and web browsing) for civic and political purposes has been predicted by education, extroversion, age (middle age), community group membership, collective efficacy and activism [START_REF] Carroll | Community collective efficacy: Structure and consequences of perceived capacities in the Blacksburg Electronic Village[END_REF][START_REF] Carroll | Social and Civic Participation in a Community Network[END_REF], [START_REF] Kavanaugh | Participating in Civil Society: The case of networked communities[END_REF]. These are also among the key defining characteristics of opinion leaders. Thus, traditional Internet use tends to reinforce the long established pattern of more educated and active members of a community using email and web browsing for greater political and civic participation.

The effects of Internet use for civic and political purposes include increased awareness and knowledge of issues, greater sharing of information and heterogeneity of discussion networks, and increased community involvement [START_REF] Carroll | Community collective efficacy: Structure and consequences of perceived capacities in the Blacksburg Electronic Village[END_REF][START_REF] Carroll | Social and Civic Participation in a Community Network[END_REF][START_REF] Hampton | Grieving for lost network: Collective action in a wired suburb[END_REF][START_REF] Kavanaugh | When everyone's wired: Use of the Internet for networked communities[END_REF]. But if these effects only reinforce prior social patterns of involvement, traditional Internet services are primarily increasing the participation of previously more active members of a community. We have also found in our prior studies a slight increase in the involvement of those "slightly less politically active but still interested in the community. In this paper we report on findings comparing predictors of traditional Internet use for civic purposes with predictors of social media use for civic purposes. We find similar effects but for a broader, more diverse population due possibly to the game-changing nature of social media.

Our study is inspired by the preliminary finding by Smith and colleagues [START_REF] Smith | Pew Internet & American Life Project[END_REF] that the use of social media (social network sites, blogs, micro-blogs) for civic purposes is not as strongly associated with socio-economic status (SES), measured by education and income, as traditional Internet use (e.g., email and web browsing) is very important to our work. Another relevant finding from a study of blog readers asserts that participation in online discussion was predicted by education, but not in the direction traditionally found in research [START_REF] Zúñiga | Digital Democracy: Reimagining Pathways to Political Participation[END_REF]. "Instead, it is those with less education who demonstrate more online expressive participation," (p. 46) in blogs. This suggests that web logs (i.e., blogs) may provide a pathway to political discussion and civic participation among those typically less politically active, the silent majority, and possibly the politically disillusioned and disengaged from conventional politics.

In our study results reported here, we expand on our prior (2005) model of the civic effects of Internet use [START_REF] Kavanaugh | Participating in Civil Society: The case of networked communities[END_REF] that seeks to explain the influence of exogenous and intermediating variables on respondents' self-reported level of community involvement since getting on the Internet. In this paper, we re-tested and compared this earlier model with social media use variables to assess their influence on civic engagement. We test the following hypotheses: 1) younger adults are using social media for civic purposes more than older adults; 2) social network factors, such as group membership, will be a stronger predictor of using social media for social purposes than 'staying informed' and 'activism'; and 3) the use of social media for civic purposes is less strongly correlated to education than the use of traditional Internet for civic purposes. Our empirical study should provide an important comparison with earlier studies as well as with our own prior results [START_REF] Godara | The Efficacy of Knowledge Sharing in Centralized and Self-organizing Online Communities: A Comparative Analysis of Weblogs vs Centralized Discussion Forums[END_REF][START_REF] Kavanaugh | Models of local government blogging: Design trade-offs in civic engagement[END_REF][START_REF] Kavanaugh | When opinion leaders blog: New forms of citizen interaction[END_REF][START_REF] Tauro | Deliberation in the Wild: A Visualization Tool for Blog Discovery and Citizen-to-Citizen Participation[END_REF].

The area of Blacksburg, Virginia and environs offers a rich opportunity to investigate the effects of Internet vs. social media use on community involvement. The majority (about 85%) of Blacksburg residents (population roughly 42,000 in 2010) are affiliated as faculty, staff, or students with the land grant university known as Virginia Tech. The neighboring town of Christiansburg (with a population of about 21,000) and Blacksburg lie within rural Montgomery County (population almost 95,000), governed by a Board of Supervisors that has jurisdiction over such services as the school district and public libraries, and some shared infrastructures, such as transportation and roads. While Blacksburg tends to be slightly above the national average in socio-economic status (as measured by education and income), in terms of Internet and social media penetration, the town of Christiansburg and the rest of Montgomery County are similar to national penetration rates on these measures. The study results reported here are from households throughout Montgomery County, including Blacksburg and Christiansburg.

Methods

We used purposeful sampling and combined several recruitment efforts in order to obtain a representative sample of the population. These include, along with the N of completed surveys: 1) a random sample of Montgomery County households (N=90); 2) a random sample of Virginia Tech undergraduate students (N=70); and 3) 200 local community organizations with public Facebook pages or websites (N=62). The representativeness of the sample was evaluated based on its similarity to 2010 Census statistics. The demographic statistics for our sample are similar to the demographics for the County.

The majority of respondents were white (93.8%), slightly higher than the census (87.6%). Blacks were the same as in the census (4.0%). There were a few areas of discrepancy, such as, overrepresentation of females (59.3%) vs the census (48.3%), and median income ($50,000+) compared to the census median income ($43,229). The higher median income for Blacksburg and Christiansburg -which were slightly overrepresentedlifted the overall average. Similarly, on Education only 6% of our respondents completed high school or less whereas the census has over a third (36.1%) for Montgomery County.

Survey questions asked respondents about their interests and activities, attitudes and psychological attributes, affiliation with community groups, traditional Internet and social media use, and demographic factors. This survey drew upon validated and reliable questions from prior studies, such as the HomeNet study [START_REF] Kraut | Internet paradox revisited[END_REF], over a decade of our prior survey research in Blacksburg and environs [START_REF] Kavanaugh | The impact of community computer networking on community involvement and social capital[END_REF][START_REF] Kavanaugh | Community networks: Where offline communities meet online[END_REF][START_REF] Kavanaugh | Net gains in political participation: Secondary effects of Internet on community[END_REF][START_REF] Kim | Toward a Model of Political Participation among Young Adults: The role of local groups and ICT use[END_REF] and relevant civic and community studies that incorporated questions about known indicators of social and civic participation [START_REF] Brady | Political Participation[END_REF][START_REF]Social Participation in Urban Society[END_REF][START_REF] Putnam | Bowling Alone: The collapse and revival of American community[END_REF][START_REF] Shah | Connecting" and Disconnecting with Civic Life: Patterns of Internet use and the production of social capital[END_REF][START_REF] Shah | Information and Expression a Digital Age[END_REF], [START_REF] Zúñiga | Digital Democracy: Reimagining Pathways to Political Participation[END_REF].

With our 2012 survey data, we tested the same exogenous, mediating variables or constructs, and dependent variable that we had tested in earlier path models (2005): (1) civic, political, and social interests and activities, (2) psychological attributes, such as extroversion, political and collective efficacy, and trust, and (3) Internet use [START_REF] Kavanaugh | Participating in Civil Society: The case of networked communities[END_REF], [START_REF] Kim | Toward a Model of Political Participation among Young Adults: The role of local groups and ICT use[END_REF]. We compared the results with a new dependent variable: social media use for civic purposes. Our measures used Likert scales that captured respondent's agreement on frequency scales. We created typologies by aggregating variables linked to common constructs. In order to test for interrelationships among the variables, we generated correlation coefficients and tested each of these constructs for reliability.

For our exogenous variables we relied on theory and previous studies to select and test several demographic factors that predict community involvement and civic participation [START_REF] Hampton | Neighbors Online. Pew Internet & American Life Project[END_REF]. These include education, extroversion and age (M=47.7 years). Age and age squared are both are in the model, although only age squared is shown), education, and extroversion. We measured extroversion with Likert-scale items of agreement regarding self-reported psychological and behavioral attributes: being talkative and outgoing (Cronbach alpha = 0.88. Our mediating variables include Staying Informed, Membership, Discussion Network, and Activism (for a detailed description of constructs please see http://diggov.vt.edu/constructs).

Dependent Variables. We created two path models to test our dependent variables: Traditional Internet Use for Civic Purposes and Social Media Use for Civic Purposes. The construct Traditional Internet Use for Civic Purposes was comprised of frequency scale items that ranged from never to several times a day. Items measured respondent's civic activities on the Internet. The questions asked respondents how often in the past six months had they used the internet for the following purposes: (1) to look for information on the Town of Blacksburg website; (2) to look for information on the Montgomery County website; (3) to look for information on Blacksburg Electronic Village (BEV) website; (4) to post factual information for other citizens; [START_REF] Almond | The Civic Culture: Political attitudes and democracy in five nations[END_REF] to express an opinion in online forums or group discussions; (6) to communicate with other residents about local concerns or issues that interest you; [START_REF] Dahl | Democracy and its Critics[END_REF] to get national or global news; and (8) to get local news. The alpha coefficient for this scale was a respectable 0.77.

To measure our second dependent variable, Social Media Use for Civic Purposes, we used questions adapted from a set of questions developed and used by the Pew Internet Study-Social Media and Political Engagement (2012). Participants responded to four questions that asked them if they used the social media to receive community news or to be civically active in a group (liking or disliking a civic group, making comments about a group, and joining a community group). The measures used Likert scales that captured respondent's agreement on frequency scale that ranged from strongly disagree to strongly agree. The items held well together (α=0.85).

Statistical Analysis. Guided by our earlier research and our 2005 'civic effects of Internet Use' path model, we employed confirmatory structural equation modeling (SEM) using LISREL software to examine the explanatory power of the same variables and constructs with our 2012 survey data: education, extroversion, age (external variables), and membership, staying informed, discussion networks and activism (mediating variables) on the use of traditional internet (email and web browsing) for civic purposes (N=204). We also used SEM to examine the explanatory power of the same variables on the use of social media for civic purposes (N=155, SNS users only).

To determine whether the models were a good fit for the data, we compared the relative performance of tested models across several measures: (a) the Normed Fit Index (NFI), (b) the Comparative Fit Index (CFI), (c) the Root mean Square Error of Approximation (RMSEA), and (d) the ratio of the chi-squared statistics to the degrees of freedom for the model. The CFI and NFI are both used because they both show that a value between .90 and .95 is considered marginal, above .95 is good; below .90 is considered to be a poor fitting model. We also used the ratio of the chi-squared statistics to the degrees of freedom for the model and RMSEA as measures of relative fit with lower values taken as good model performance [START_REF] Shah | Information and Expression a Digital Age[END_REF].

We used SPSSS to perform some ANOVA, Correlation and Multiple Regression tests to predict differences in Internet use and social media use for civic purposes, by demographic variables (education and age) and the constructs of the model. We tested additional constructs in our study, such as, collective efficacy and political efficacy, but we report only those constructs and variables that were significant.

Results

Demographics and Use of Internet and Social Media

As noted above, demographically our survey respondents are generally representative of Blacksburg and surrounding Montgomery County (Census Report, 2010). The average education of respondents is college graduate. The overwhelming majority (92%) is white; more than half are female. Regarding use of the Internet and social media, the vast majority (95%) reported using the Internet and a slightly smaller majority said they use social media (80%). The highest percentage of heavy users of social networks sites (SNS), such as Facebook and MySpace, are aged 18 to 29 years (48%), followed by 30 to 39 year olds (20%). Those aged 40 to 49 and 50 to 64 year old were about the same as 12% and 13%, respectively. Only 7% of adults aged 65 and older report using SNS. In general our respondents are similar to those of US national surveys (Pew, 2012). However, the average SNS and Twitter user in our sample is younger and more educated than the typical SNS and Twitter user in the US based on same year (2012) statistics from studies by the Pew Internet & American Life Project. This is important considering how demographic variables correlate with civic participation and Internet or social media use.

Correlations among key constructs. Education was positively correlated with traditional Internet use for civic purposes (r=0.273, p<0.05), but education was not correlated with social media use for civic purposes (given limited space we have published the correlation matrix for all variables in our path models online at http://diggov.cs.vt.edu/files/Correlation matrix.pdf). There were small to moderate positive relationships between extroversion, local group membership, political discussion network, activism, and the use of both traditional Internet and social media for civic purposes.

Respondents who were older (r=-0.197, p<0.001), belonged to more groups (r=-0.226, p<0.001), stayed more informed (r=-0.650, p<0.001), and had higher levels of activism (r=-0.475, p<0.001) also had higher measures on political discussion network. Respondents who reported using traditional Internet for civic purposes (r=-0.387, p<0.001) were likely to have higher measures on political discussion network compared to respondents who reported using social media for civic purposes (r=-0.290, p<0.001).

Results from our ANOVA tests show that younger adults, aged 18-39 years, are more likely than adults over 40 to report that compared to traditional Internet (email and web browsing), using social media is more helpful in connecting with people like themselves in the local area (F=10.147, p=.00, M=5.6). Respondents aged 18-29 years (F=3.28, p=.006, M=5.32) report that compared to using traditional Internet, using social media is more helpful in feeling connected with a diversity of people in the local area. Younger adults aged 18-39 years are more likely to use social media for civic purposes.

Path Models: Traditional Internet vs Social Media for Involvement in Local Issues. To test for differences with the path models we developed in 2005, we tested two path models with our new survey data that compare outcome measures of traditional Internet use (Figure 1) and social media use for civic purposes (Figure 2). We found that our key exogenous and mediating variables predict the use of both traditional Internet and social media for civic purposes. Education has a direct positive effect (β=.20, p<.001) on the use of both traditional Internet and social media for civic purposes. However, the indirect effect of education is greater for traditional Internet use (β=.14, p<.01) than for social media use for civic purposes (β=.09, p<.05).

Group membership is positively associated with use of traditional internet for civic purposes (β=.11, p<.10), although the relationship is much stronger for the use of social media for civic purposes (β=.17, p<.05). A linear combination of political discussion network, membership and activism explained 39% of the variance in the use of traditional Internet for civic purposes (Figure 2); the same variables explained 26% of the variance in use of social media for civic purposes (Figure 2). Factor loading for both models (Figures 1 and2) were above 0.8 indicating a strong goodness of fit. Composite reliabilities of each component were uniformly higher than 0.8 while the Cronbach alpha scores were around 0.8, thus meeting stipulated thresholds [START_REF] Nunnally | Psychometric Theory[END_REF].

The overall fit statistics for the saturated models were good, yielding a chi-square value of 13.28 with 10 degrees of freedom (RMSEA= .04, CFI= .99, NFI = .98) for the traditional Internet use model (Figure 1) and a chi-square value of 15.86 with 12 degrees of freedom (RMSEA=.04, CFI= .99, NFI =.96) for the social media use model (Figure 2).

Discussion and Conclusions

The VTS project aimed to build an online "town square" to create a portal where citizens are able to learn about important local issues, identify and share local information with friends and family, and foster citizen deliberation about news and events in the community. As theoretical foundation for this paper identifies, traditional democratic theory evaluates the strength or weakness of democracies [START_REF] Almond | The Civic Culture: Political attitudes and democracy in five nations[END_REF] by the engagement of its full range of citizens in deliberative processes and political participation behaviors. However, Dewey [START_REF] Smith | Pew Internet & American Life Project[END_REF] is one of the first to explicitly articulate the need to evaluate media systems in place and whether the media characteristics foster deliberative opportunities. While this project does not aim to evaluate the quality of deliberation, it does assess use of media with different characteristics (e.g., traditional print and broadcast media, Internet, social media) and the relationships with a range of civic and political attitudes and behaviors.

Our analysis of the correlations and two path models provides a range of important insights about community members' Internet use, social media use and community involvement. We examined the strength of the relationship between education and the use of traditional Internet versus social media for civic purposes, particularly at the local level. We also analyzed new survey data in a path model that we developed earlier to try to test for differences in independent and mediating variables that explain the use of traditional Internet versus social media for civic purposes.

Our results are consistent with the preliminary 2009 Pew study finding that education is not as strongly correlated with the use of social media for civic purposes as it is with the use of traditional Internet for civic purposes. In the new path models, education has a direct positive effect on the use of both traditional Internet and social media for civic purposes. However, the indirect effect of education is greater for traditional Internet use than for social media use for civic purposes. Moreover, extroversion (outgoing and talkative), one of the defining characteristics of opinion leaders, is not significant in explaining the use of social media for civic purposes. Thus, the differences in characteristics between traditional Internet and social media appear to play an important role in fostering citizen engagement, especially by appearing to reduce the barrier related to education and seemingly engaging citizens beyond those typically identified as opinion leaders. While it is important for scholars to validate our findings in other communities and contexts, it is encouraging to report that social media extends the range and type of participant participating in civic affairs in the community.

Findings from this study appear to suggest that the communication systems, particularly features of social media, are doing a better job at serving citizens interested in engaging in civic and political affairs by engaging a broader range of citizens and reducing a significant barrier (e.g., education) to civic engagement.

Finally, political discussion network and activism, while still significant in both models, are not as strong predictors for using social media for civic purposes as they are for using traditional Internet for civic purposes. In the path model explaining social media use for civic purposes, group membership is a stronger predictor than it is for the model explaining traditional Internet use for civic purposes. These findings underscore the observation that some traditional predictors of political engagement are not as powerful in the social media environment and suggest that the social media environment broadens the characteristics of individuals engaged in civic purposes.

These findings suggest that respondents who use social media for civic purposes are not opinion leaders --those who seemed to dominate the pattern of traditional Internet use for civic purposes. At the same time, our findings indicate the highly social nature of the civic involvement of people who use social media. Young adults (aged 18-39) are more likely than older adults to use social media for civic purposes. This is important because it shows that social media does lead to increased civic involvement especially for younger adults who traditionally have not been as involved in local issues as older adults --a long standing trend that ended with the first Obama election in 2008.

The path models reported in this paper suggest that at least two groups typically underrepresented in civic and political processes, younger adults and those with lower education levels, are using social media to become more involved in their local communities. We encourage researchers to test the path models from this study in their local environment in hopes that the research community will learn more about the ways communication tools, particularly affordances of social media, work to enlarge the access to and sharing of local information, encourage deliberation, and lead to increased citizen participation in civic and community affairs.

*Figure 1 .

 1 p<.05. **p<.01. ***p<.001 Model explaining Traditional Internet Use for Civic Purposes

*Figure 2

 2 p<.05. **p<.01. ***p<.001 Model Explaining Social Media Use for Civic Purposes Model

Acknowledgement

We are grateful for support from the National Science Foundation (SES-1111239) of which this work is part. We would also like to thank our collaborators Manuel Pérez-Quiñones, Naren Ramakrishnan and Joon Byoung Kim. Any errors, opinions, recommendations, findings or conclusions in this mateiral are those of the authors and do not necessarily reflect the views of the National Science Foundation.


Marius Rohde Johannessen
email: marius.johannessen@hbv.no

Genres of Participation in Social Networking Systems: A Study of the 2013 Norwegian Parliamentary Election

Keywords: eParticipation, online campaigning, social networking systems, genre theory, Norway

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Online campaigning has been on the agenda for Norwegian political parties since the parliamentary election in 2001. Back then the Internet played a marginal role, but it was expected that this would change in coming election campaigns [START_REF] Hestvik | Partier, velgere og nye medier. Ny kommunikasjon?[END_REF]. In 2007 there were some initial attempts at campaigning through social media, and Barack Obama's successful 2008 campaign served as an inspiration for the 2009 parliamentary election [START_REF]Name-withheld[END_REF].

The reason for this interest in moving towards digital media can be found in the Norwegian research project power and democracy, which conducted a study of the state of democracy in Norway between 1998 and 2003. One of the main conclusions of the study was that representative democracy is in decline. Citizens are no longer loyal to one political party, or participating in broad social movements such as labour unions. Citizens instead move from one party to the next, one issue to the other. Sin-gle issues have become more important than party politics. This means that power is slowly moving from the parliament towards lobbying and non-governmental organizations (NGO's) [3]. Norwegian politicians are signalling that they want more citizen dialogue and user-involvement in the political process [START_REF] Brandtzaeg | eCitizen 2.0: The Ordinary Citizen as a Supplier of Public Sector Information[END_REF], and they are increasingly attempting to achieve this through SNS' and other digital communication channels in order to reach out and communicate directly with voters [START_REF] Karlsen | A Platform for Individualized Campaigning? Social Media and Parliamentary Candidates in the 2009 Norwegian Election Campaign[END_REF]. The purpose of this paper is to revisit the SNS communicative strategies of Norwegian political parties. In the 2009 parliamentary election there was evidence of an emerging system of genres [START_REF] Yates | Genre Systems: Structuring Interaction through Communicative Norms[END_REF] for political communication, and the political parties reported that their SNS efforts would only increase with time. This paper thus aims to compare the findings from the elections in 2009 and 2013, in order to examine if the genre system emerging in 2009 has changed significantly between the two elections, and to discover if SNS' are being used in line with the principles of online politics as outlined by Chadwick and Howard [START_REF] Chadwick | Introduction: New directions in Internet politics research[END_REF].

The rest of the paper is structured as follows: Section two provides an overview of related research, specifically on the topics of social networking and online campaigning. Section three presents the research approach of the study, and sections four and five present the findings and conclusions with some possible directions for future research.

2

Related research

Democracy can be conceptualized in a number of ways, and is practiced differently in different contexts [START_REF] Markoff | A Moving Target: Democracy[END_REF]. Most of these conceptualisations involve some sort of interaction between citizens and government. Communication between citizens and the politicians elected to rule is considered a necessity in the democratic process, and government generally recognise the value of participation [START_REF] Casteel | Habermas & Communicative Actions[END_REF][START_REF] Bryson | Designing Public Participation Processes[END_REF] . While the value of citizen participation is recognized both in academia and government, recent political trends show that political engagement is decreasing. Across the western world fewer people are members of a political party [START_REF] Van Biezen | gone? The decline of party membership in contemporary Europe[END_REF] or vote in elections [START_REF] Gray | Declining Voter Turnout in Advanced Industrial Democracies, 1950 to 1997[END_REF]. Governments rely more on expert assessment [START_REF] Rayner | Democracy in the age of assessment: Reflections on the roles of expertise and democracy in public-sector decision making[END_REF] and power moves towards markets and the legal system [START_REF] Østerud | Power and Democracy in Norway: The Transformation of Norwegian Politics[END_REF]. Partly as a consequence of this, the past decade has seen a number of technologically driven participation projects, as there are indications that social media presence increases participation [START_REF] Effing | Social Media and Political Participation: Are Facebook, Twitter and YouTube Democratizing Our Political Systems?[END_REF].

Online campaigning in SNS: Towards politics 2.0

Social Networking Services (SNS') are web-based services where users can 1) create and maintain a public or private profile. 2) create a list of other users they are connected to, and 3) see their own and others' contact lists [START_REF] Boyd | Social Network Sites: Definition, History, and Scholarship[END_REF]. The most popular SNSs are those that focus on user-generated content, participation, openness and network effects [START_REF] Anderson | What is Web 2.0? Ideas, technologies and implications for education[END_REF]. Social networking is not mainly about technology, but about covering people's needs for access to and sharing of information, collaboration and the creation of identity and self. As such, SNS should be treated more as a cultural than technological phenomenon [START_REF] Rose | The role of social networking software in eParticipation[END_REF]. To reap the benefits of SNS, owners of information needs to open their data, think in terms of collaborative production of ideas and content, and to share ideas with others in order to create better information [START_REF] Williams | Wikinomics: How mass collaboration changes everything[END_REF].

Political campaigning is all about convincing the public that your party has the best policy. The election campaign has a very big influence on the outcome of the parliamentary election. More than 40 % of Norwegian voters wait until the final weeks of the campaign before deciding who gets their vote, and many change their mind several times during the campaign [START_REF] Aardal | I valgkampens hete: strategisk kommunikasjon og politisk usikkerhet[END_REF]. Younger voters are more likely to cast their vote differently from one election to the next [START_REF] Aardal | Norske velgere: en studie av stortingsvalget 2005[END_REF]. When the Norwegian newspapers became politically independent, political parties lost the power to decide what should be on the public agenda [3]. The media has taken over this role, and are trying to write about the things they believe voters are concerned about [3,[START_REF] Aardal | Norske velgere: en studie av stortingsvalget 2005[END_REF]. Political parties in campaign mode are constantly working to move citizens towards those media channels controlled by the parties, where SNS' along with party and candidate web sites are among the most important [START_REF] Karlsen | A Platform for Individualized Campaigning? Social Media and Parliamentary Candidates in the 2009 Norwegian Election Campaign[END_REF]. SNS' play an important part in what has been called the hybridised media system, where traditional and new media are both reliant upon each other [START_REF] Chadwick | The Political Information Cycle in a Hybrid News System: The British Prime Minister and the "Bullygate" Affair[END_REF], and thus SNS' expand the possible modes of election campaigning [START_REF] Hong | Which candidates do the public discuss online in an election campaign?: The use of social media by 2012 presidential candidates and its impact on candidate salience[END_REF].

Chadwick and Howard [START_REF] Chadwick | Introduction: New directions in Internet politics research[END_REF] introduce the concept of politics 2.0, based on the original conceptualisation of web 2.0 made by O'Reilly [START_REF] O'reilly | What is web 2.0? Design patterns and business models for the next generation of software[END_REF]. This concept can be used for analysing the media-specific effects of campaigning in SNS', and can function as a guideline for practitioners and as a lens for understanding and evaluating SNS activities. The concept consists of up of 7 themes: 1) The Internet is a platform for political discourse where the ability to rapidly respond to events through setting up new web sites or SNS groups is essential. Distributed networks of contributors, online activist campaigns and citizen journalism can create valuable information, which leads to the second theme: 2) The collective intelligence emergent from political web use.

3) The importance of data over particular software and hardware applications is a theme showing that not only does SNS' provide rich input from citizens, but it is also a source of demographic data about potential voters. 4) Perpetual experimentalism in the public domain. This theme shows how SNS' can contribute to more inclusive politics, by taken citizen advice into consideration and by providing a platform where political parties can instantly respond to comments, polls, petitions and media events. 5) The creation of small scale forms of political engagement. Data mash-ups such as fix my street, as well as mobile applications where citizens produce data through mobile apps or through documenting issues using mobile cameras allows for lowthreshold forms of engagement. This is tied in with the sixth theme 6) The propagation of political content over multiple applications. Finally, the seventh theme includes the new interactive features found in SNS' such as multimedia content and hyperlinks: 7) Rich user experiences on political web sites. The importance and potential outcomes of interactive content have been discussed in several earlier studies [START_REF] Johannessen | Genres of communication in activist eParticipation: a comparison of new and old media[END_REF][START_REF] Shepherd | The evolution of cybergenres[END_REF][START_REF] Shepherd | The functionality attribute of cybergenres[END_REF].

2.2

Genre theory

Genre theory can be applied to study the role of communication in social processes, and has been applied to several eParticipation studies [START_REF] Päivärinta | The Genre System Lens on E-Democracy[END_REF][START_REF] Saebø | Understanding Twitter Use among Parliament Representatives: A Genre Analysis[END_REF][START_REF] Saebø | Autopoietic cybergenres for e-Democracy? Genre analysis of a web-based discussion board[END_REF][START_REF] Johannessen | Genres of Participation in Social Networking Systems: A Study of the 2009 Norwegian Parliamentary Election[END_REF]. Genres evolve over time, in the interplay between institutional practice and the people communicating [START_REF] Yates | Genres of Organizational Communication: A Structurational Approach to Studying Communication and Media[END_REF]. Genre theory provides us with a lens for detailed understanding of political communication, beyond the observation of technological functionality [START_REF] Orlikowski | Genre Repetoire: The Structuring of Communicative Practices in Organizations[END_REF]. Originally, genres were recognized by having similar form and content, where form refers to physical and linguistic features, and content to themes and topics of the genre [START_REF] Yates | Genres of Organizational Communication: A Structurational Approach to Studying Communication and Media[END_REF]. Later, when the Internet became more popular, functionality offered by the medium delivering the genre was added as a third construct [START_REF] Shepherd | The evolution of cybergenres[END_REF]. A set of genres used by a given community can be seen as a genre system [START_REF] Yates | Genre Systems: Structuring Interaction through Communicative Norms[END_REF] The genre system of a community can reveal a "rich and varied array of communicative practices" shaped by community members in response to norms, events, time pressure and media capabilities [START_REF] Orlikowski | Genre Repetoire: The Structuring of Communicative Practices in Organizations[END_REF]. Genres are useful for studying SNS', as the introduction of new media over time often leads to new communication practices which genre theory allows us to map and analyze [START_REF] Saebø | Autopoietic cybergenres for e-Democracy? Genre analysis of a web-based discussion board[END_REF]. By studying communication genres instead of the technology used to communicate, we can discover how communication changes and evolves over time [START_REF] Orlikowski | Genre Repetoire: The Structuring of Communicative Practices in Organizations[END_REF], and by including the technological functionality of the medium the genre is enacted within, we can better understand the interplay between the social and the technical [START_REF] Shepherd | The evolution of cybergenres[END_REF].

Genres can be defined by examining form, functionality and content, by using the 5w1h-method By asking where, why, when, who, what and how, we can uncover the purpose, contents, placement in time, location, participants, structure and medium for communication [START_REF] Yates | Genre Systems: Structuring Interaction through Communicative Norms[END_REF][START_REF] Yoshioka | Genre taxonomy: A knowledge repository of communicative actions[END_REF]: Where tells us where the communication takes place, the medium being used, or the physical location. Why explains the purpose of the genre, as understood by those using it. When refers to the time where communication takes place. For example, the "job application" genre is enacted when applying for a job, and needs to be in by a set date. Who defines the actors involved in communication, the sender and receiver of the genre. What is the content of the genre, and defines what is being communicated, and any relations to other genres. Finally, How describes the technical needs for delivery of the genre, for example which medium is being used, or any other technical necessities.

Research approach

The objective of this paper is to examine if the genre system emerging in 2009 has changed significantly between 2009 and 2013, and to discover if SNS' are being used in line with the principles of politics 2.0. The study was conducted using a qualitative, interpretive approach. Data for the 2009 study was collected through semistructured interviews with representatives from the seven political parties that were represented in the parliament before the election (Socialist Left, Labor, Center Party, Liberals, Christian people's party, Conservatives and the Progress Party). Five interviews were made face to face, while two of the parties only had time for e-mail inter-views. All of the interview subjects were hired by their respective parties to work with social networking strategies. The Interviews lasted between 40 and 77 minutes, and were taped and transcribed. In addition, content analysis of the SNS' used by the parties were applied. This made it possible to compare what the information workers said with what their employers, the politicians, were actually doing, and to create an overview of the genre system in SNS political communication. Data was collected between March and May in 2009. The genre systems of 2009 and 2013 are presented following the guidelines from [START_REF] Päivärinta | A Genre-Based Method for Information Systems Planning[END_REF].

Data for the 2013 election was collected between June and September 2013, mainly through content analysis of the SNS' used by the seven political parties represented in parliament. In total, 6000 posts and comments were collected and a selection of these was coded using the 5W1H method. When no new genres were identified, the remainders of the posts were quickly scanned to see which genre category they matched. Finally, representatives of the political parties was contacted and asked to verify the interviews from 2009. They were given the summary of the transcripts from 2009 and asked if anything had changed in the time between the two elections.

Findings

Summary of findings, 2009 election

The interviews made in 2009 identified three objectives for political communication in SNS'. These are dialogue with citizens, contributions from citizens, and involvement in party activities, and are presented in table 1. The genres identified in the 2009 SNS' can be analyzed as to which of these "genre objectives" they support (table 2), and this knowledge can be applied by site administrators and politicians in such a way as to facilitate the use of genres which are most likely to lead to the desired objective. Policy comments are comments from citizens on party policy. These come in many forms: Wall or discussion posts on Facebook, in Twitter messages and blog comments. Calls for action mainly originate with the party, but are often distributed through citizens supporting the party making the call. This genre incorporates calls for volunteers, competitions and calls for action in specific cases. Several parties have created Facebook groups for specific parts of their policy. Calls are presented in video, with links to the video posted to Facebook and Twitter. The Q&A genre is perhaps the genre that citizens are least satisfied with. Many questions on Facebook walls remain unanswered, or are answered unsatisfactorily. Some citizens ask why politicians bother having a presence in SNS when they do not engage in conversations with citizens. Appeals to the party are similar to policy comments. The difference is that where policy comments reflect directly on the party's political program, appeals are more specific, asking what the party intends to do with this or that matter. There is some frustration among citizens when these are not answered.

Dialogue

Greeting is an interesting genre. At his birthday, Prime Minister Jens Stoltenberg received hundreds of greetings wishing him a happy birthday. In other cases, we see greetings cheering the party on to fight for a specific case. This genre, while not directly political, could be seen as narrowing the gap between politician and citizen, creating a sense of personal attachment between the two. Personal accounts are mainly found in blogs, as response to politicians asking for the stories of individual citizens. The most interesting example is where the minister of health asks for people's stories as input to a major health reform. Video responses from citizens are rare, but some examples exist. These are typically posted as responses to competitions where parties ask citizens to contribute. There are also responses between parties, where video is used in a similar manner to newspaper debates, and responses between politicians belonging to the same party.

The 2009 election showed an emerging genre system for SNS campaigning. However, there were some challenges identified through content analysis. The main challenge was the mismatch between the expectations of citizens and politicians. Citizens expected answers to their questions and input, but this rarely happened. Responses to party calls for input on specific issues received a lot more comments than other politi-cian-initiated genres, indicating that citizens need to be heard and feel that their input is used for something if they are to participate.

Genre system 2013 election

The responses from the political parties did not indicate any major changes in the strategies compared to their responses in 2009. Their ambition to use SNS for communicating with voters stands fast, and is perhaps formulated even stronger. Google+ and Instagram have entered the mix of services being used, but Facebook remains the most important medium for most of the parties, with Twitter coming second. Blogs are not reported to be much used in 2013, while blogging was a popular activity in 2009.

One major change is in the amount of people following the parties and their leaders, as well as a lot more activity in 2013 compared with 2009. Due to space limitations, table 3 There are some interesting observations to be made from table 3. First, the number of followers and posts made by followers has increased quite dramatically. While most parties in 2009 had less than 1 % of their voters as followers, in 2009 this had risen to between 3,5 % and 12,9 %, which means that Facebook alone reaches a significant part of the voters for most of the parties. Differences in demographics between voter groups could perhaps explain some of the difference between the parties. Activity was also a lot higher in 2013, with a significant increase in the number of posts. Second, there seems to be little if any correlation between the number of votes received and the increase in followers. The progress party is by far the most popular Facebook party, but also the party with the largest drop in votes. While an in-depth analysis of this is beyond the scope of this paper, these numbers nevertheless indicate that SNS could be more valuable for dialogue rather than as a campaign tool. Finally, the numbers from 2013 seem to confirm an increased focus on person over party. The leaders of the three largest parties had had 349 342 (Labour), 89 411 (conservatives) and 119 261 (Progress party) followers, far more than any of their parties. The politicians' activity seems to reflect this, as they share a lot more "private" pictures from their travels. The prime minister before the election, Jens Stoltenberg, published a YouTube video where he posed as a taxi driver, talking politics with the people he was chauffeuring. The video received 1.6 million hits and generated a lot of attention in both social and mainstream media. Most of the genres from 2009 are still present in 2013, except for the video response genre, which was not very successful in the previous election. Personal accounts are still present, but not as common. Instead, personal experiences are incorporated into other genres, such as debate and policy comments. In addition, several new genres have emerged. While there was little debate in 2009, 2013 introduces this genre. Citizens provide input and other citizens as well as politicians and the party replies. Support and non-support are other new genres, where citizens show they support ("steady course. Four new years of labour") or not support ("about time someone else takes the wheel") the party. Following the non-support genre is disgruntlement, where those are unhappy with the a party, usually the ruling ones, will present more or less sarcastic comments about the party and attribute a range of unpleasant comments about the party and its politicians. Finally, the link genre simply consists of links to news articles and other sources. This is often accompanied by a short statement ("Do something about this, please!") or question ("Why is this allowed/not allowed"?). Linking to content to support a position shows the richness of digital communication, and the easy by which relevant information can made available to people.

Genre

In summary, comparisons of the data from the two elections show that we are moving towards an increasingly rich genre system for political communication. While citizens in 2009 would complain about nonresponsive politicians, this is much less of an issue in 2013. The parties ask for input on a wide range of policy issues, and receive hundreds of replies to issues that people care about the most. This post, from the newly elected government, illustrates the change: "Thank you, everyone who took the time to comment on the government's budget. We have sent all your comments to the PM. Have a lovely weekend". Attached to the post was a picture of the Prime minister holding a sign with a Facebook like button and the text "comments from Facebook". After a few minutes, there were several comments praising the party for listening to its voters.

One challenge which still remains is that the language use within the genres is yet to be consolidated. While traditional channels for citizen and organisational input has relied on a formal language and a set format, citizens providing input through SNS do so with a language ranging from highly informal, with lots of typing errors, exclamation marks and capital letters to the formal language more common in political communication. This can lead to a re-definition of what should be considered "valuable" input by politicians, similar to the argument made by for example Graham [START_REF] Graham | Beyond "Political" Communicative Spaces: Talking Politics on the Wife Swap Discussion Forum[END_REF] .

4.3

Towards politics 2.0?

The genre systems found in the two election campaigns show that we are approaching what can be called "politics 2.0". Several of the seven themes identified by Chadwick and Howard [START_REF] Chadwick | Introduction: New directions in Internet politics research[END_REF] are relevant in this context.

The increase in numbers of both followers and interactions, and the nature of these interactions clearly shows that the Internet and SNS' are becoming a platform for political discourse. Political parties have also become a lot better at replying quickly to comments, which further adds to this impression. As for the theme collective intelligence, the tone and style of posts made by citizens show that a voice is provided to those who are not usually seen as contributors to public debate. This could indicate that our collective intelligence is extended to those who are not otherwise included in the political process. The theme perpetual experimentalism in the public domain shows how SNS' can contribute to more inclusive politics through citizen advice and instant responses. While this theme covers a lot more than the genre and content analysis of this paper, there are indications that this is happening. Parties respond to comments and questions from citizens, and a lot of the posts made by parties are in response to current media events. The theme small scale form of political engagement is only present to a limited degree, and was actually more relevant in 2009 with the video response genre. In 2013, there are a few examples related to the use of camera phones, and there have been contests where open government data have been used for creating mash-ups in other contexts not relevant for campaigning. The sixth theme, propagation of political content over multiple applications, is very much present, as all of the political parties spread the same types of content across all of their SNS presences. This helps to draw users to content posted on the party's own web site, which makes up a high percentage of the posts made by parties. The final theme, rich user experiences, is becoming increasingly visible, and has improved markedly between 2009 and 2013. In 2009, most parties were criticised for posting pamphlets, newsletters and one-way communication, in 2013 all of them present multimedia-rich and interactive content, responding to current issues. When the Socialist party had poor results in the polls, they started their "I vote socialist because…"-case, where politicians and sympathisers made posters citing their reasons for voting and uploaded pictures of themselves to Facebook and Twitter. Info graphics presenting specific policy areas are common, as are pictures and video from various events and links to content posted elsewhere. All in all, these themes contribute towards making politics more personalised, providing access to content and information and could contribute towards a renewal of political interest.

Conclusion

Norwegian political parties have used the Internet in election campaigns since 2001, but SNS was first introduced in 2007. The 2009 election was the first time Norwegian parties were expected to really go in for SNS as a campaign tool. A genre system emerged in 2009, and in 2013 the genre system used in SNS' political communication had matured significantly, and the number of users and contributors has increased greatly. The ways in which SNS' are used are moving us towards "politics 2.0", but still further research is needed. Social network analysis could be applied to examine more in-depth how communication flows in SNS', and while genre analysis provides insights into how citizens and politicians communicate, there is still a need to combine this with a more holistic content analysis to fully examine the dynamics of social networks. Finally, on-and offline data should be compared to examine for example if the higher voter turnout of the 2013 election can be attributed to SNS', or if there are other more important deciding factors. Nevertheless, this study clearly shows that political communication in SNS's is contributing to the political parties' election campaign tool box.

Table 1 :

 1 Political party objectives for SNS participation

			Contribution	Involvement
	Why	Involve citizens in debate	Knowledge about citizen	Raise funds. Get people to
			concerns	volunteer
	When	Continuous	Election time	Election time
	What	Conversation between citi-	Q&A. Voter stories	Competitions, membership
		zens and politicians		forms, information
	Who	Politicians, party members,	Politicians, party members,	Voters, sympathizers
		citizens	voters
	Where SNS, web site	SNS, web site	SNS, web site
	How	Encourage dialogue.	Encourage contributions and	Competitions, theme sites,
		Open and personal language.	questions from voters	cross-publication
		Citizen-generated content.

Table 2 :

 2 Genres identified in 2009 election

	Genre	Producer	User	Medium	Related to
	Policy	Citizen	Citizen,	Facebook, blog,	Dialogue, contribution
	comment		party	Twitter, video
	Call for	Citizen,	Citizen	Facebook, Twitter,	Contribution, involve-
	action	party		video	ment
	Q&A	Citizen	Party	Facebook, Twitter, blog	Dialogue
	Appeal to	Citizen	Party	Facebook, Twitter, blog	Dialogue, contribution
	party
	Greeting	Citizen	Party	Facebook, blog	Dialogue
	Personal	Citizen	Party	blog	contribution
	accounts
	Video	Citizen,	Citizen,	YouTube	Contribution
	response	party	party

Table 3 :

 3 summarises the numbers for Facebook only, as this is by far the most used medium. Comparison of Facebook activity 2009 and 2013

	Party	2009				2013
		Voters	Followers % f/v	Posts	Voters	Followers % f/v	Posts
	Socialist	166 361 1176	0,7 %	111	116 021 13027	11,2 %	565
	Labour	949 049 1745	0,18 %	167	874 769 59065	6,7 %	1021
	Center	165 006 446	0,27 %	60	155 357 6642	4,2 %	250
	Christian	148 748 266	0,17 %	24	158 475 6469	4,08 %	290
	Lib.democrats 104 144 1075	1,03 %	100	148 275 12505	8,4 %	546
	Conservatives 462 458 1331	0,28 %	194	760 232 26854	3,5 %	928
	Progress party 614 717 5835	0,94 %	688	463 560 59980	12,9 %	873

Table 4 :

 4 Genres identified in 2013 election

		Producer	User	Medium	Related to
	Policy	Citizen	Citizen, party Facebook, blog,	Dialogue,
	comment			Twitter, video	contribution
	Call for	Citizen, party Citizen	Facebook, Twitter, video Contribution,
	action				involvement
	Q&A	Citizen	Party	Facebook, Twitter, blog	Dialogue
	Appeal to party Citizen	Party	Facebook, Twitter, blog	Dialogue,
					contribution
	Greeting	Citizen	Party	Facebook, blog	Dialogue
	Personal	Citizen	Party	blog	contribution
	accounts
	Debate	Citizen, party Citizen, party Facebook	Contribution
	Support	Citizen	Party	Facebook, Twitter	Dialogue
	nonsupport	Citizen	Party	Facebook, Twitter	Dialogue
	Link	Citizen, party Citizen, party Facebook	Contribution
	Disgruntlement Citizen	Party	Facebook, Twitter	Dialogue


F Haas

S Courtin

Experimental Study of Nuclear Molecular States

Keywords: Light Heavy-Ion Reactions, Resonances, Nuclear Molecules PACS: 25.70.Ef, 25.70.Bc, 21.60.Gx

Resonance phenomena in light heavy-ion collisions are experimentally well established and their observation can be understood in terms of the number of open reaction channels. In the cases of 12 C+ 12 C → 24 Mg, 12 C+ 16 O → 28 Si and 24 Mg+ 24 Mg → 48 Cr, similar and strikingly narrow resonances have been observed. New results or proposed experiments on the γ, fragment and particle decays of these resonances are presented.

RESONANCES IN LIGHT HEAVY-ION COLLISIONS

The observation of resonances in light heavy-ion collisions is a well established experimental fact. Such phenomena have been seen for composite systems with masses less than 60 and, in the case of identical boson systems for example, in the reactions 12 C+ 12 C, 14 C+ 14 C, 16 O+ 16 O, 24 Mg+ 24 Mg and 28 Si+ 28 Si. The selective occurrence of resonances can be explained by phase space arguments. This is shown on Fig. 1a. [1] where for a variety of light heavy-ion collisions, the number of open channels (NOC) is represented as a function of the grazing angular momentum (L g ). Strong resonance effects have been observed in systems where NOC is small, such systems involve the α-like nuclei 12 C and 16 O but also the non α-like nucleus 14 C which has a closed neutron shell, a semi-closed proton shell, a first excited state above 6 MeV and behaves, what NOC is concerned, almost like 16 O. Another remarkable feature seen in Fig. 1 is the very small value of NOC for 12 C+ 12 C over a large range of L g , i.e., a large range of bombarding energies. This explains why the resonance phenomena have always been strongest in 12 C+ 12 C. In Fig. 1b. are also shown a few examples of resonant excitation functions [1] measured for certain integrated direct reaction channels of the indicated systems. The structures are more or less pronounced depending on the system and in particular on NOC.

In the case of 12 C+ 12 C, 12 C+ 16 O and 16 O+ 16 O where strong resonance structures have been seen from the Coulomb Barrier (CB) to ~ 5 MeV par nucleon, experiments have been performed at higher energies to study the evolution of these structures. For the 12 C+ 12 C reaction, the results are reported in Fig. 2a. In the case of the 90° elastic scattering [2] it is seen that above 5-6 MeV per nucleon, the narrow structures become large structures which in other words means that the resonant effects become refractive effects. The deep minimum observed at E lab = 102.1 MeV corresponds to the second Airy minimum while the first is predicted by the optical model calculations to occur at E lab = 132 MeV. The near-side, far-side decompositions of the elastic scattering angular distributions (Fig. 2.b.) at the two Airy minima energies show clearly the importance of the refractive far-side amplitudes [3][4][5][6]. If confirmed by future experiments, a first Airy minimum at 132 MeV means that the energy region above ~ 150 MeV corresponds to the dark side of the nuclear rainbow and also signifies the end of the famous series of 'Airy' elephants … (Fig. 2.c.). It is quite remarkable to note that strong refractive effects are only seen in systems showing strong resonance effects. This is because both effects require weak absorption. In the case of observable refractive effects [3][4][5][6], deep nucleus-nucleus potentials have been deduced which not only describe nuclear scattering but also nuclear molecular structure as for example in the case of 12 connection can only be more firmly established through measurements of their spins and parities, fragment and γ decay widths. Alpha clustering is well known in light nuclei where α cluster bands exist for example in 16 O, 18 O, 20 Ne and 44 Ti. Recent and important work on neutron-rich Be and C isotopes [8,9] has established and characterized states in these nuclei with 2αxn and 3αxn configurations.

RESONANCES VERSUS MOLECULAR STATES

Cluster or molecular states are deformed states for which the γ decay should contain specific signatures. In the case of the 16 O α cluster band (4p-4h configuration) with states at Ex = 6.05 (0 + ), 6.92 (2 + ) and 10.36 (4 + ) MeV, this is indeed the case because strongly accelerated E2 transitions of 65 and 27 W.u. have been measured for the 4 + → 2 + and 2 + → 0 + transitions, respectively.

What heavier clusters and particularly molecular states are concerned, it is expected that they can be reached through heavy-ion resonances which populate the composite systems at high excitation energies where the density of states is large. The best cases to study are those for which the resonance width and thus also the spreading width are small. The 12

THE RESONANT RADIATIVE CAPTURE REACTIONS

Resonances were observed by Sandorfi [START_REF] Sandorfi | Treatise on Heavy Ion Science[END_REF] 25 years ago in the radiative capture reaction 12 C( 12 C,γ) 24 Mg. In this pioneering work, only the γ decay to low-lying states in 24 Mg could be observed. Recently this capture reaction was studied again with improved experimental techniques [START_REF] Jenkins | [END_REF] and it was demonstrated that there was strong competition between different modes of decay (see Fig. 3.). It was in particular shown [START_REF] Jenkins | [END_REF] that there was strong feeding of the 24 Mg K π = 2 + band and also of 24 Mg states around 10 MeV which could be the predicted shape isomers with 12 C-12 C structure. It was also demonstrated that due to these additional decay channels the radiative capture cross-section is 4 ot 5 times stronger than reported previously [START_REF] Sandorfi | Treatise on Heavy Ion Science[END_REF]. A similar study is going to be performed in a near future by our group on the resonant radiative capture reaction 12 C( 16 O,γ) 28 Si [START_REF] Sandorfi | Treatise on Heavy Ion Science[END_REF] using the 0° spectrometer Dragon at Triumf (Vancouver) and its associated BGO γ-array with the aim to look for 12 C-16 O doorway cluster states in 28 Si predicted to lie at E x ~ 15 MeV [7].

THE RESONANT 24 Mg+ 24 Mg REACTION

Our research programme on this system is performed at the Legnaro Tandem and is focused on the decay of the narrow resonance J π = 36 + at E cm = 45.7 MeV [12]. In an experiment using the fragment spectrometer Prisma and its associated γ-array Clara, the feeding on and off resonance of the inelastic channels was studied (see Fig. 4). Resonance strength is observed essentially in inelastic channels involving the 0 + , 2 + and 4 + members of the 24 Mg ground state band. A full account of this experiment is given in another contribution to ENS'05 [START_REF] Salsac | Contribution in the present Proceedings of ENS'05[END_REF]. For the resonance under study, only 30% of the flux has been observed up to now in the inelastic and transfer channels. We propose to search for the missing flux in the 2α (or 8 Be) fusion channel feeding the known 40 Ca deformed or superdeformed states (see Fig. 4). The aim of the study is of course to establish an eventual link between the 48 Cr molecular states fed through the

CONCLUSIONS

To establish more firmly the connection between heavy-ion resonances and nuclear molecules, new experiments on the resonance decay modes are called for. For the lighter 12 C+ 12 C → 24 Mg or 12 C + 16 O → 28 Si cases, the most promising research programme actually underway is the study of the resonant radiative capture reactions and the search for enhanced γ-decay through specific cluster doorway states. For the heavier 24 Mg+ 24 Mg → 48 Cr case, the narrow resonances correspond to much higher excitation energies in the composite systems and the proposed studies are more devoted to the study of the fragment and particle decay channels with the aim to establish a link between molecular states and low lying superdeformed states.

  C+ 16 O [7]. b. a.

FIGURE 1 .

 1 FIGURE 1. a. Number of open channels as a function of grazing angular momentum for C+C, C+O, O+O collisions [1]; b. Excitation functions of angular integrated direct reaction channels for the collisions indicated [1].

  It has been shown in the previous section that the existence of resonances in light heavy-ion collisions is experimentally well established. However, their relation to large molecular states in the composite systems is still a debated question. Such a a. b.c.

FIGURE 2 .

 2 FIGURE 2. a. 90° elastic scattering excitation function for 12 C+ 12 C [2], the full line is an optical model calculation; b. Near-side/Far-side decompositions of the angular distributions at the two first Airy minima at E lab = 102.1 and 132 MeV; c. The gross structures in the excitation function represented as a series of so-called 'Airy' elephants.

  C+ 12 C and 24 Mg+ 24 Mg reactions are two striking examples where similar narrow width resonances (Γ = 100-200 keV) have been observed under rather different conditions: around the Coulomb Barrier for 12 C+ 12 C with low spins and composite 24 Mg excitation energies of ~ 20 MeV; at twice the CB for 24 Mg+ 24 Mg with high spins and composite 48 Cr excitation energies of ~ 60 MeV. Our experimental research programme in Strasbourg has been focused on these two cases and in particular on the γ and fragment decay modes of the narrow resonances.

FIGURE 3 .

 3 FIGURE 3. Competition between different γ decay modes in resonant radiative capture reactions like

24

  Mg+24 Mg resonances and the 40 Ca superdeformed states.

FIGURE 4 .

 4 FIGURE 4. Competition between different fragment and particle decay modes of a 24 Mg+ 24 Mg resonance forming a 48 Cr nuclear molecule.

C( 12 C,γ) 24 Mg or 12 C( 16 O,γ)28 Si.