Minh Quang Tran
email: m.tran@open.ac.uk

Shailey Minocha
email: s.minocha@open.ac.uk

Dave Roberts
email: d.roberts@open.ac.uk

Angus Laing
email: a.w.laing@lboro.ac.uk

Darren Langdridge
email: d.langdridge@open.ac.uk

A Means-end Analysis of Consumers' Perceptions of Virtual World Affordances for E-commerce

Keywords: Consumer experience, e-commerce, interaction design, laddering interviews, means-end analysis, qualitative research, user experience, virtual worlds

Virtual worlds are three-dimensional (3D) persistent multi-user online environments where users interact through avatars. The affordances of virtual worlds can be useful for business-to-consumer e-commerce. Moreover, affordances of virtual worlds can complement affordances of websites to provide consumers with an enhanced e-commerce experience. We investigated which affordances of virtual worlds can enhance consumers" experiences on ecommerce websites. We conducted laddering interviews with 30 virtual world consumers to understand their perceptions of virtual world affordances. A means-end analysis was then applied to the interview data. The results suggest co-presence, product discovery, 3D product experience, greater interactivity with products and sociability are some of the key virtual world affordances for consumers. We discuss theoretical implications of the research using dimensions from the Technology Acceptance Model. We also discuss practical implications, such as how virtual world affordances can be incorporated into the design of e-commerce websites.

Introduction

Virtual worlds, such as Second Life [START_REF] Rymaszewski | Second Life: The Official Guide Second Ed[END_REF], are being used by businesses for real world e-commerce. For example, Toyota and Reebok have created virtual stores and showrooms in Second Life for consumers to interact with virtual simulations of their real world products [START_REF] Goel | If You Build it Will They Come? An Empirical Investigation of Consumer Perceptions and Strategy in Virtual Worlds[END_REF]. These and other real world businesses that create a presence in virtual worlds can increase their engagement with consumers [START_REF] Park | Virtual World Affordances: Enhancing Brand Value By Virtual World Affordances : Enhancing Brand Value[END_REF] and enhance the value of their brands [START_REF] Barnes | Brand Value in Virtual Worlds: An Axiological Approach[END_REF]. Given the potential benefits of using virtual worlds for real world e-commerce, researchers are beginning to investigate how virtual worlds can be better utilised by businesses [START_REF] Cagnina | Beyond E-Business Models: The Road to Virtual Worlds[END_REF].

In this paper, we investigated which virtual world affordances facilitate ecommerce from the consumer"s perspective. For our study, we defined affordances as features of a technology that determine ways a technology can be used [START_REF] Norman | Affordance, Conventions, and Design[END_REF]. Our investigation is based in Second Life. Second Life (http://secondlife.com) is a virtual world that was launched in 2003 and continues to attract 800,000 visitors each month. It supports many activities, including education, socialising, gaming and e-commerce. The e-commerce activity in Second Life mostly involves virtual items [START_REF] Bakshy | The Social Dynamics of Economic Activity in a Virtual World[END_REF]. However, an understanding of the affordances for e-commerce with virtual items is useful for understanding how e-commerce in virtual worlds with real items can occur.

Some virtual world affordances used for e-commerce with virtual items are likely to be the same affordances used for e-commerce with real items. For example, virtual worlds afford the rendering of 3D objects in a 3D environment. This affordance allows consumers to have a virtual experience with real or virtual products, which can help consumers to learn about and evaluate products before buying [START_REF] Li | Characteristics of Virtual Experience in Electronic Commerce: A Protocol Analysis[END_REF]. Furthermore, the affordance of a persistent multi-user environment enables and sustains online communities. Online communities are known to influence consumers" experiences [START_REF] Kozinets | E-Tribalised marketing?: The Strategic Implications of Virtual Communities of Consumption[END_REF] regardless of whether the consumption is real or virtual. The aim of this paper is to identify the virtual world affordances that enhance consumers" real world ecommerce experiences. Our investigation has led to an understanding of when and why certain virtual world affordances are useful for e-commerce.

Research Question

The research question we have addressed is "which affordances of virtual worlds can enhance consumers" e-commerce experiences?" The research question has been investigated through laddering interviews and means-end analysis. These techniques are commonly applied in consumer research to understand consumers" preferences for brands, advertisements and products [START_REF] Wansink | Using Laddering to Understand and Leverage a Brand"s Equity[END_REF]. We have applied these techniques to understand consumers" perceptions of virtual world affordances for e-commerce. Laddering interviews were used to elicit the underlying reasons consumers have for preferring certain affordances. Means-end analysis was then used as a structured method to analyse the qualitative data from the laddering interviews [START_REF] Veludo-De-Oliveira | Discussing Laddering Application by the Means-End Chain Theory[END_REF].

Background

The theoretical framework of this study is based on the concept of the service encounter. The service encounter includes all the interactions that the consumer performs during the provision of a service [START_REF] Bitner | The Service Encounter: Diagnosing Favorable and Unfavorable Incidents[END_REF]. In the context of e-commerce, the service encounter centres on the online purchase transaction. Moreover, the prepurchase and post-purchase interactions are also a part of the service encounter. In this study, we have elicited consumers" perceptions of how virtual world affordances can enhance the e-commerce service encounter.

An important concept within the e-commerce service encounter is the consumer"s ability to move between different online and offline service channels. Consumers choose appropriate service channels based on their needs during a service encounter. For example, additional support for the purchase can be provided through high street stores, telephone and mail-order catalogues [START_REF] Dijk | Consumers, Channels and Communication: Online and Online Communication in Service Consumption[END_REF]. This study starts with the premise that virtual worlds are able to address certain needs that consumers have during the ecommerce service encounter.

Virtual worlds are said to incorporate the convenience of e-commerce websites with the richness of interactions of high street stores [START_REF] Hemp | Are You Ready for E-tailing 2.0?[END_REF], but there is little empirical evidence to support this claim. Despite their potential, virtual worlds seem to be under-utilised for real world e-commerce. Currently, in April 2011, there are only a small number of virtual worlds that support online purchasing of real world products: some examples of virtual worlds designed specifically for e-commerce are Avaya (http://avayalive.com), NearWorld (http://london.nearglobal.com), and Trillenium (http://www.trillenium.com). Part of the motivation for this paper is to examine the reasons for the under-utilisation of virtual worlds for real world e-commerce and to understand what can be done to increase their usage.

According to the Technology Acceptance Model [START_REF] Davis | Perceived Usefulness, Perceived Ease of Use, and User Acceptance of Information Technology[END_REF], the usage of technology is determined mainly by perceived usefulness and perceived ease-of-use. However, given the relative novelty of virtual worlds, our investigation was conducted in an exploratory manner. We did not limit the study to only investigate pre-determined dimensions of technology use, such as perceived usefulness and perceived ease-ofuse; we allowed other dimensions to emerge from the data as well.

Data Collection

We conducted 30 interviews with participants who had e-commerce experience in Second Life. The participants also had e-commerce experience on websites. Participants were recruited and interviewed in Second Life through the use of avatars. The recruitment procedure and interview protocol were approved by our university"s ethics committee. We also followed Second Life"s community standards [START_REF]Second Life Community Standards[END_REF] to ensure that the study was not violating Second Life"s usage policy.

To locate participants, we visited shopping and socialising areas in Second Life. In these areas, we scouted for prospective participants by first reading their user profiles. User profiles contain public information provided voluntary by the user. The user profiles were utilised as a preliminary screening tool. Based on the profiles, we could identify experienced users of Second Life and we could identify users who had shopping experiences in Second Life. Prospective participants were then sent a private text message (similar to an instant message (IM)) inviting them to participate in the research study. Those that agreed were given a virtual note card containing detailed information about the study and our contact information. A second note card was given to participants as a consent form. Participants were then asked if they were over 18. If they were over 18, they were asked to consent to participate through text messaging.

Demographic information (real life age, real life gender, real life occupation, and country of residence for participants) was requested from participants at the end of each interview. Providing demographic information was optional. Thus, some participants did not reveal all their demographic information. With the information provided to us, we know that 13 males and 13 females participated. Four participants did not reveal their gender. Participants resided in USA [START_REF] Bakshy | The Social Dynamics of Economic Activity in a Virtual World[END_REF], UK (3), Romania (3), Spain (2), New Zealand (2), Italy (2), India (2), France (1), Belgium (1), Australia [START_REF] Rymaszewski | Second Life: The Official Guide Second Ed[END_REF] and Germany [START_REF] Rymaszewski | Second Life: The Official Guide Second Ed[END_REF]. Four participants did not reveal their country of residence. Participant"s ages ranged from 18 to 55. Eight participants did not reveal their age. The mean age of known participants was 29.1.

All the interviews were conducted in Second Life, using private text messaging. Interviews typically lasted 45 minutes to 1 hour. The interviews were conducted in English. Interviews were conducted between May 2010 and Dec 2010. Participants were given an honorarium worth two Great Britain pounds that was paid in Linden Dollars, Second Life"s currency.

The interviews started with background questions to elicit participant"s experiences of shopping in Second Life and shopping on websites. Participants were then asked to recall features of websites that they liked and disliked. This question was to prime participants so that they could more easily answer the main interview question. The main interview question was, "can you think of Second Life features that would make shopping on websites better or easier?

As participants recalled features, we proceeded to apply the laddering technique. The laddering technique involved asking a series of probing questions, such as "why is the feature important to you?" The probes were meant to uncover participants" preferences for specific features of virtual worlds during the e-commerce service encounter.

Data Analysis

We analysed the interview data using means-end chain analysis [START_REF] Reynolds | Laddering Theory, Method, Analysis, and Interpretation[END_REF]. The analysis started by extracting ladders, or means-end chains, from the data. Each ladder contains three components: an attribute, a consequence and a value.

 An attribute refers to any feature of the virtual world, but specifically something that can be interacted with or supports an interaction.  A consequence is the outcome of performing the interaction.  A value is the psychological need or desire associated with the consequence. Each ladder represents participants" reasoning about why they think a feature of the virtual world is useful for e-commerce. An example of a ladder is: having avatars (attribute) to interact with real people (consequence) to feel a connection with others (value). Extracting ladders involved two steps: making annotations and linking the annotations.

1. Annotating involves identifying relevant segments of the data and describing them either as referring to an attribute, a consequence or a value. An additional description is given to the annotation that refers to its meaning. For example, an annotation could be: [value: connection with others]. For this annotation, "value" refers to the ladder component and "connection with others" refers to its meaning. 2. Linking annotations involves making explicit the connection between specific attributes, consequences and values that are mentioned by participants. The purpose is to create complete ladders with each of the three components: an attribute, a consequence and a value.

In the excerpt below, we show an example of how the data is annotated and linked to create a ladder. [attribute: having avatars] The data was annotated by using a bottom-up strategy, that is, by working from the data instead of using pre-determined concepts. Through several iterations, the annotations were eventually consolidated into a set of 51 codes, comprising of 16 attributes, 19 consequences and 16 values. We list the codes in the next section.

Codes derived from the annotation process

Table 1 shows our codes and their frequency of appearance in the data. The percentage represents the frequency of the code relative to the total number of ladders. 1 were used to derive ladders during the linking process.

Ladders derived from the linking process

Alongside the annotation process, ladders were derived through the linking process described above. 114 ladders were derived from the data: a mean of 3.8 ladders per participant. The ladders were then entered into LadderUX. LadderUX is a data analysis software package for laddering research [START_REF] Abeele | Laddering the User Experience[END_REF]. The software creates hierarchical value maps based on the formula described in Reynolds and Gutman"s seminal paper on laddering [START_REF] Reynolds | Laddering Theory, Method, Analysis, and Interpretation[END_REF]. First, a matrix is created that cross-links all the codes. Each cross-link between codes is given a score depending on how frequently a link between the codes appears. Then, a map is generated based on the scores. Only those scores which are above a defined cut-off level are shown in the map. The researcher defines the cut-off level. Cut-off levels from 3 to 5 are most common in laddering research. The cut-off level we have used for our map is 4 (see Figure 1, section 6.2).

Results

In this section, we summarise the results of the analysis. First, we discuss the attributes, consequences and values. Then, we discuss the hierarchical value map and finally, we re-visit the research question of this paper. For the results section, participants are referred to as consumers.

Summary of attributes, consequences and values

Attributes

Attributes are features of virtual worlds. The most frequently mentioned attributes by consumers are shown in Table 2. Only attributes with a frequency higher than 9% are discussed in this paper. At the 9% cut-off, we found a close fit between the number of elements in the summary tables (e.g. Table 2) and the number of elements in the hierarchical value map. Attributes that are related are grouped and discussed together.

Relationship between attributes, consequences and values

Figure 1 shows the hierarchal value map based on our analysis (please see section 5.2). The thickness of the lines between codes in the map indicates a higher link frequency between the codes. Functional consequences noted in the map relate to observable outcomes, whereas psycho-social consequences relate to personal outcomes (such as a change in emotion or thought). From the map, we can derive the reasons why and when consumers may choose virtual worlds over websites. We call these reasons "motivational patterns", a term from Gengler et al. [START_REF] Gengler | A Means-End Analysis of Mothers" Infant Feeding Choices[END_REF]. To derive motivational patterns, we start with the values at the top of the map and then follow the links downwards. Motivational pattern 1 is about enjoying the experience. This comes often from discovering new products and interacting with people. The 3D multiuser environment facilitates discovering new products and interacting with people.

Motivational pattern 2 is about acquiring information about products.

Consumers gather information about products by interacting with 3D simulations of products in virtual stores. Consumers also learn by interacting with store attendants in 3D spaces. Motivational pattern 3 is about making informed decisions. This is possible because consumers can interact with virtual simulations of products, which are rendered and displayed in a 3D environment. Motivational pattern 4 is about feeling cared for. Consumers feel cared for because they are interacting with real people, which is possible because a virtual world is a multi-user environment. Motivational pattern 5 is about personal safety. Personal safety refers to concerns about privacy: for example, protecting personal information and banking details. Personal safety and privacy are related to trust. Consumers perceive interactions in virtual worlds to be more trustworthy because the interactions are interpersonal and because there are ways to verify a business"s real world identity from websites or their stores. These motivational patterns provide an understanding of how virtual worlds can enhance the e-commerce experience from the consumer"s perspective. In the next sub-section, we discuss affordances and answer the original research question.

Which affordances of virtual worlds can enhance consumers' e-commerce experiences?

The research question for this study was, "which affordances of virtual worlds can enhance consumers" e-commerce experiences?" We answer this question by returning to the hierarchical value map (Figure 1, section 6.2). To identify the affordances, we start with the attributes from the map and then follow the links from the attributes upwards. Thus, the affordances that can enhance consumers" experiences are:

 Affordance 1: Multi-user environments to allow shopping with others  Affordance 2: 3D environments to allow products to be easily discovered  Affordance 3: Store attendants and 3D objects to support product learning  Affordance 4: 3D objects to support more interactivity with products  Affordance 5: Social networks to increase consumer"s trust We discuss implications of these affordances and consumers" perceptions of the affordances in the next section.

Technology acceptance

Understanding consumers" perceptions of virtual world affordances can help predict why virtual worlds may be adopted by consumers for the e-commerce service encounter. Two dimensions of perception that are highly correlated with technology acceptance are perceived usefulness and perceived ease-of-use [START_REF] Legris | Why Do People Use Information Technology? A Critical Review of the Technology Acceptance Model[END_REF]. Usefulness refers to how proficiently a user will be able to complete a task with a technology. Ease-ofuse refers to how easily a user can learn and utilise a technology. Both dimensions will be discussed in relation to virtual world affordances.

This study suggests that virtual worlds are perceived to be useful when the task is to learn about products. Virtual worlds are also perceived to be useful for interacting with other people. Therefore, consumers are likely to use virtual worlds for ecommerce when they want to learn about products or interact with others in a more effective and efficient manner.

This study indirectly addresses the dimension of perceived ease-of-use. Perceived ease-of-use is alluded to by our findings on enjoyment. Enjoyment, more commonly conceptualised as satisfaction, is related to usability. In turn, usability is related to ease-of-use [START_REF] Lederer | The Technology Acceptance Model and the World Wide Web[END_REF]. Consumers may choose to use virtual worlds for e-commerce when they want to enjoy the e-commerce experience. To what extent the hedonic aspect (enjoyment) and utilitarian aspects (efficiency and effectiveness) overlap is uncertain. However, our study suggests that consumers perceive virtual worlds have the ability to offer both enjoyment and utility.

Four other dimensions of consumer"s perceptions also emerged from our study. The dimensions are: compatibility, perceived service quality, perceived trust and information richness. These dimensions are also part of a website technology acceptance model by Chen and Tan [START_REF] Chen | Technology Adaptation in E-commerce: Key Determinants of Virtual Store Acceptance[END_REF].

Compatibility refers to the overlap between the consumers" personal beliefs and what they believe the technology represents. In other words, it relates to prejudices consumers" hold for or against a technology. The concept of compatibility originates from Rogers" theory on diffusion of innovations [START_REF] Rogers | Diffusion of Innovations 5 th Edition[END_REF]. Bessiere et al. [START_REF] Bessiere | Acquiring a Professional "Second Life:" Problems and Prospects for the Use of Virtual Worlds in Business[END_REF] describes an example of how compatibility can influence virtual world acceptance. They found users in their study associated virtual worlds "primarily with socialising and playing, rather than working". The belief that virtual worlds offer a playful rather than a serious environment was an adoption barrier. Similarly, consumers may have prejudices against adopting virtual worlds for e-commerce as they may think that virtual worlds are not for making real world transactions.

Service quality is another dimension of consumers" perception. Service quality refers to the expectations of consumers about the service they will receive from a business. One facet of service quality is empathy, which is defined as "caring, individualised attention" towards consumers [START_REF] Buttle | SERVQUAL: Review, Critique, Research Agenda[END_REF]. Our study found that empathy could be an advantage of shopping in virtual worlds. Consumers in our study explained that virtual worlds allow them to interact synchronously with sales personnel; the sales personnel were then able to answer questions immediately and in a personalised manner. Therefore, the interactions in virtual worlds were perceived as involving more empathy.

Consumers in our study perceived trust as another advantage of virtual worlds. However, trust varies depending on the situation. Consumers were not trusting of virtual worlds when making a transaction, but they were trusting of virtual worlds for advice. Consumers trust advice in virtual worlds because it comes from real people with whom they feel were co-present. The realism of the shopping environment may also be a reason for consumer"s increased trust [START_REF] Nassiri | Increasing Trust Through the Use of 3D E-commerce Environment[END_REF].

Information richness is the last dimension we discuss. Information richness is defined as "quality of product information and the extent of product comparison" [START_REF] Chen | Technology Adaptation in E-commerce: Key Determinants of Virtual Store Acceptance[END_REF]. Information richness enables the consumer to make an informed purchase decision. It relates to product learning, but also to the search, sense-making and decision-making process. Several consumers in our study discussed aspects relating to information richness. The 3D environment and 3D simulations help increase information richness. The interactions with other consumers and sales personnel also help consumers gather more information while in virtual worlds. Therefore, in terms of technology acceptance, information richness is another explanation why consumers" may choose virtual worlds for e-commerce.

Multi-channel consumption and the service encounter

In the previous sub-section, we discussed some opportunities and barriers for adoption of virtual worlds for e-commerce. In this sub-section, we start with the assumption that virtual worlds are already a viable option for e-commerce. Another question then arises: when will consumers choose to use virtual worlds instead of other service channels?

Consumers have many options of channels during a service encounter, such as websites, high street, telephone, and so on. Virtual worlds are not likely to replace any of the existing service channels; more likely, virtual worlds will become another option to complement the existing channels. Research on multi-channel consumption behaviour suggests perceived risk, need for interpersonal contact, convenience, and price differential are factors that determine which channel consumers will choose for the service encounter [START_REF] Black | Modelling Consumer Choice of Distribution Channels: An Illustration from Financial Services[END_REF]. Furthermore, research suggests consumer"s choice of channel is context-specific and idiosyncratic [START_REF] Dijk | Consumers, Channels and Communication: Online and Online Communication in Service Consumption[END_REF]. Our study identifies some contexts where virtual worlds can enhance the service encounter, such as when consumers need to talk to sales personnel, have the desire to browse or when they would like to interact with 3D simulations of products.

Different service channels have different affordances. Our study contributes towards identifying the affordances of virtual worlds that make virtual worlds a unique service channel. Understanding the key affordances of virtual worlds can help designers make decisions on how to best utilise virtual worlds during a service encounter. For example, the consumer may want to learn about a product without leaving their home, but is disappointed with the images or product descriptions on websites. The consumer could instead enter a virtual world to interact with 3D simulations and discuss the product with sales personnel, or ask family and friends to accompany them to 3D stores to help in the decision-making process. Then, the consumer could return to the website to complete the purchase transactions because they may perceive the website is trustworthy and the payment will be handled securely.

Practical Implications for E-commerce on Websites

In some cases, it may not be practical to have the service encounter entirely in a virtual world. In these cases, affordances can be abstracted and incorporated into the design of e-commerce websites. In this section, we discuss five key affordances of virtual worlds for e-commerce that can be incorporated into websites. The five affordances we discuss are: facilitating co-presence, greater support for product discovery, virtual experience, playful experience with products, and building trust through interpersonal interactions. These affordances are related to the affordances mentioned in section 6.3.

Allowing the feeling of co-presence

Websites should build features to support co-presence [START_REF] Gerhard | Embodiment and Copresence in Collaborative Interfaces[END_REF]. For example, co-presence can be supported through a chat feature embedded into websites. Shopping on websites would then become a collaborative activity, allowing consumers to shop "together". There is an inherent trade-off in privacy and anonymity with this affordance. However, in some situations, consumers may desire it. Based on our study, this affordance is related to the personal desire to enjoy the experience.

Greater product discovery and browsing opportunities

Websites should build features for product discovery through browsing. Browsing is a different kind of information-seeking behaviour from searching [START_REF] Toms | Understanding and Facilitating the Browsing of Electronic Text[END_REF]. With browsing, the consumer does not necessarily know what they are looking for. Many e-commerce websites are designed for efficient search, but not for efficient browsing. Our study suggests that consumers appreciate the ability to browse as well during e-commerce. 3D environments, which have rich visuals, can facilitate browsing. On websites, rich visuals can be combined with intelligent recommender systems to provide consumers opportunities to browse products online.

Having virtual experiences with products

Websites should include features to provide an increased interactive experience with products to reproduce the virtual experiences that consumers have from using virtual worlds. Virtual experiences results from interacting with 3D rendered products that are "moveable, rotatable, zoomable, customizable, and animated" [START_REF] Zhenhui | Virtual Product Experience: Effects of Visual and Functional Control of Products on Perceived Diagnosticity and Flow in Electronic Shopping[END_REF]. Another advantage of incorporating virtual experiences is that consumers feel more engaged when they learn with 3D objects compared to learning about products through text and 2D images [START_REF] Li | Characteristics of Virtual Experience in Electronic Commerce: A Protocol Analysis[END_REF].

Having playful experiences with products

Websites should build features to allow consumers to play with products. This is closely related to the affordance of having virtual experiences. However, playful experiences result in more than just learning about a product. Playful experiences result in engagement and enjoyment as well. The key feature related to playfulness is flexibility to manipulate virtual products in different contexts. For example, consumers discussed mixing and matching clothing items or rearranging different furniture pieces in a room. To support play and playfulness, websites should consider increasing their product selection (variety), adding elements onto their website that are modifiable and adding elements that do not directly serve utilitarian purposes [START_REF] Chung | Antecedents of Perceived Playfulness: an Exploratory Study on User Acceptance of General Information-Searching Websites[END_REF].

Building trust through social networks and interpersonal interaction

Websites should support some form of social networking to allow consumers to connect and communicate with each other. This affordance is perceived to enhance trust. Trust, in this case, might come from having social capital. This is sometimes called "social trust" and it is correlated with a higher probability that consumers will make purchase transactions [START_REF] Mutz | Social Trust and E-Commerce: Experimental Evidence for the Effects of Social Trust on Individuals" Economic Behavior[END_REF]. Large online retailers (e.g. amazon.com and ebay.com) have incorporated this feature with success by allowing customers to review products on their websites.

Limitations and Directions for Further Study

This study provides an empirically-grounded understanding of virtual world affordances for e-commerce. However, as with any empirical research, validity and generalisability should be considered in relation to how the data was collected and sampled. The participant sample for our study was experienced users of virtual worlds. Therefore, we presume the participants already enjoy using virtual worlds. They may also be more trusting of interactions in virtual worlds because of their familiarity with places, people and the interface in virtual worlds. Participants who are inexperienced with virtual worlds may have different perceptions compared to the participants in our study. Further studies with participants who are inexperienced with virtual worlds could provide more perspectives to complement the findings of this study.

Another point worth considering is that the experiences of our participants were based on their consumption of virtual items. Although the consumption processes may be similar for real and virtual items, there is still uncertainty about how much can be generalised about the use of the virtual world affordances for purchase of real world items. Further studies may want to look at consumption tasks in virtual worlds involving real items. However, this latter option is difficult given the scarcity of real world e-commerce in virtual worlds. Another option would be to perform laboratory studies where the consumption tasks and the choice of products can be controlled.

The communication mode used to collect data may be another limitation on the data. Using private text messages could influence the type and range of responses elicited during the laddering interviews. Other methods of collecting qualitative data, such as face-to-face interviews or online voice interviews, may provide a different range of responses. For example, if interviewed face-to-face, participants may be more aware of the benefits of interpersonal contact.

Finally, consumers" perceptions were based on interactions in Second Life. Second Life is one amongst many virtual worlds. The service encounter in Second Life is likely to be different from the service encounters in other virtual worlds because there would be differences between storefronts, personnel and interface designs. One solution would be to replicate the study using other virtual worlds, even with those that are not designed specifically for e-commerce, such as World of Warcraft [START_REF] Bainbridge | The Scientific Research Potential of Virtual Worlds[END_REF].

Conclusion

This study explored the potential for utilising virtual worlds as an e-commerce service channel. The study shows that consumers" perceive virtual worlds to retain the convenience of an online service channel, but have additional affordances normally associated with offline service channels. These additional affordances are copresence, product discovery, virtual experience with products, greater freedom to interact with products, and sociability. By identifying these affordances, and identifying consumers perceptions related to them, we have provided some direction for future research. We also provided priorities for interaction design of business-toconsumer e-commerce on websites and in virtual worlds.

Figure 1 .

 1 Figure 1. Hierarchical value map with cut-off level at 4.

  The three components for this ladder are: [attribute: having avatars][consequence: interact with real people][value: connection with others].

Interviewer: Can you think about how things you know about Second Life may help make shopping on a website better? Consumer27: The sense of companionship [value: connection to others]. When I shop in [Second Life] it"s usually with a couple of girlfriends [consequence: interact with real people]. Interviewer: And why is it important that you can shop with others? Consumer27: I value their opinions on style and I like to share in their pleasure at finding something that looks good on them. It"s a social activity. Interviewer: Do you think there is something else about Second Life that helps with the companionship? Consumer27: <nods> well the high-bandwidth communication Interviewer: What do you mean by that? Consumer27: Not just chat, but being able to share visually Interviewer: Share visually? Consumer27: mmHmm (sic) I can try something on and my friends tell me how it looks on me […] the 3D models could be made off of real clothes using real photo textures so the ingredients are there for this kind of experience.

Table 1 .

 1 Codes for attributes, consequences and values

	#	Code Name	Alternate Description	%
	Attributes of Second Life
	1	Store attendants	Getting immediate help from business	10.5%
	2	Teleportation	Instantly travelling to locations	0.9%
	3	High graphic detail	High resolution of images and objects	2.6%
	4	User generated content	Other users create objects in the world	1.8%
	5	Access to websites	Easy to switch to and from websites	4.4%
	6	Content creation tools	Tools for modifying in-world objects	0.9%
	7	3D environment	Environment is rendered in 3D	15.8%
	8	3D objects	Objects are rendered in 3D	21.1%
	9	Multi-user	Sharing same environment with others	9.6%
	10 Having avatars	Users embodied through an avatar	7.9%

Table 2 .

 2 Summary of most frequently mentioned attributes.When consumers discuss the 3D aspects, they usually refer to navigation and perception. Navigation relates to being able to walk through a virtual store to browse virtual shelves and see rows of virtual products. This simulates the navigation experience of a real store. Perception is about having objects represented with depth (hence, 3D). Both navigation in a 3D environment and 3D perception add to the sense of realism.

	Attribute Code	Code Frequency	Attribute	Grouped
			Group	frequency
	3D objects 3D environment	21.1% 15.8%	3D aspects	36.9%
	Store attendants	10.5%
	Social network	9.6%	Social aspects 29.7%
	Multi-user	9.6%
	Attribute group: 3D aspects
	The first grouping that emerged is 3D aspects, which was present in 36.9% of the
	ladders. This relates to 3D objects and the 3D environment of virtual worlds. It is not

Consumer16: With 3D it gives it a little better feel of what you are getting into. Interviewer: Can you say a bit more about what you mean by "feel"? Consumer16: Well to simplify. Compare Sega to Playstation 3. Sega is flat images, 16-bit. Play station has 3D graphics. Which appeals to people more? Playstation 3 of course because it gives people that sense of realness. It"s as if the objects are there in front of you vs on paper. Consumers report the 3D aspects in terms of its visual appeal. "The [3D] interface is more seductive than flat corporate web sites" (Consumer5). Beyond visual appeal, 3D aspects allow greater interactivity. Consumer23: It"s just fun […] you feel like its [real life] Interviewer: Can you tell me what is it about the '[real life] feeling' that makes it fun? Consumer23: You just feel like you"re actually in a shop, not flicking thru a mag (sic).

Consumer26: When you go shopping it"s nice especially with friends. Interviewer: Why is it nice to shop with friends? Consumer26: That it"s not boring […] you [can] talk and not walk alone through the store.

Interaction with sales personnel is also frequently mentioned as an advantage of shopping in virtual worlds.

Consumer13: [Store attendants can] help the customer find the product that best suits them, and answer questions about products. I guess going with the jewellery thing, I'm thinking of a boutique kind of experience.

Consequences

Now we look at the consequences of utilising virtual worlds for e-commerce. Consequences relate to outcomes of utilising virtual world features.


Victor Kaptelinin

Herje Wåhlen
email: herjew@gmail.com

Speaking to see: A feasibility study of voice-assisted visual search

Keywords: Voice recognition, visual search, multimodal input, voice command

The paper presents the concept, implementation, and a feasibility study of a user interface technique, named VAVS ("voice-assisted visual search"). VAVS employs user's voice input for assisting the user in searching for objects of interest in complex displays. User voice input is compared with attributes of visually presented objects and, if there is a match, the matching object is highlighted to help the user visually locate the object. The paper discusses differences between, on the one hand, VAVS and, on the other hand, voice commands and multimodal input techniques. An interactive prototype implementing the VAVS concept and employing a standard voice recognition program is described. The paper reports an empirical study, in which an object location task was carried out with and without VAVS. It was found that the VAVS condition was associated with higher performance and use satisfaction. The paper concludes with a discussion of directions for future work.

Introduction

Visual search is a crucial component of a wide range of interactions between people and digital technologies; it involves scanning displayed information to detect the presence of an object of interest, indentify its location, or explore object's properties. For instance, if the user wants to make sure that the last email message from a certain customer has been actually answered, the user may scan the list of messages in the Inbox window and search for the last message from the client, visually locate the message line, and check whether the icon on the left contains a small arrow. Finding a certain street on a digital map, looking up information about a flight on a "Departures" monitor, and many other everyday interactions with electronic displays are critically dependent on visual search. Visual search may or may not involve carrying out an action with the object of interest.

In this paper we argue that for users of digital technologies visual search may be associated with certain problems, and that there is a need to provide the users with more advanced technological support for visual search. We introduce a user interface technique, named VAVS (voice-assisted visual search), which aims to facilitate visual search by employing user's voice input for visually highlighting objects of interest.

In the remainder of this paper we present the rationale behind the VAVS technique, discuss how the technique is related to previous work, describe an interactive prototype of a system implementing the technique, and report a feasibility study, in which the prototype was employed in an object location task.

Background

Making a large number of information objects simultaneously available to the user for viewing has important advantages. In particular, it decreases the need for the user to open and "look inside" opaque containers, such as folders or pull-down menus to find objects of interest [START_REF] Benyon | Designing Interactive Systems: People, Activities, Contexts, Technologies[END_REF]. However, these advantages come with a price. In case of dense, complex displays, when the object of interest (the "target") is presented simultaneously with a large number of other objects ("distractors"), visual search becomes a more demanding task [START_REF]Information Visualization[END_REF]. Problems with visual search can be aggravated by several factors, such as users' age (children and the elderly have more difficulties than young adults), level of stress, and certain health conditions, as well as how specifically the target is defined when a person carries out a visual search task (e.g., [START_REF] Fabiani | Reduced Suppression or Labile Memory? Mechanisms of Inefficient Filtering of Irrelevant Information in Older Adults[END_REF][START_REF]Information Visualization[END_REF]). The problems are likely to worsen in the future, since the screen size and resolution of computer monitors, public information displays, tabletops, and so forth, are ever-increasing, which means displaying more (and more complex) information objects.

Helping users visually identify their objects of interest has always been high on the agenda of the design of graphical user interfaces. Well-designed interfaces visually emphasize potentially important objects and de-emphasize less important ones [START_REF] Benyon | Designing Interactive Systems: People, Activities, Contexts, Technologies[END_REF][START_REF]Information Visualization[END_REF]. Relative visual salience of displayed objects can be a static feature of an interface or it can dynamically change depending on the task context (for instance, the default button in a dialogue window is highlighted to make it easier for the user to choose the most likely option).

These strategies for supporting users' visual search seem to have been often successful in the past and they remain to be useful. However, they are, arguably, not sufficient for addressing current challenges. Making potentially relevant objects visually salient does not scale up to complex displays and complex tasks. If all potentially relevant objects are visually salient, their absolute number can be overwhelming. In addition, when a large amount of information is displayed, it might be difficult for the system to anticipate just what objects can be of importance to a particular user in a particular context and, therefore, should be visually emphasized.

These logical arguments are consistent with the evidence obtained in empirical studies. For instance, Andrews et al. [START_REF] Andrews | Space to think: Large, high-resolution displays for sensemaking[END_REF] describe "losing the cursor" and users' confusion caused by "windows and dialog boxes opening or gaining focus in unexpected locations" as common problems with large displays.

To address the problems, discussed above, we have developed a user interface technique for assisting the user in searching for objects of interest in complex displays. The underlying idea of the technique, named VAVS (voice-assisted visual search), is employing user's voice input for guiding user's visual attention.

Figure 1 shows an overall structure of a VAVS-enabled interface. The user scans an image displayed on a screen (S) to locate a certain object. The user can also use a microphone (M) to describe object's attributes, such as its name. The voice input is processed and compared with attributes of objects displayed on the screen and, if there is a match, the matching object is visually highlighted. For instance, if a person, looking at a map of Colorado on a computer display, is saying "Hmm... Mancos… Mancos…", the location of the town on the map is temporarily highlighted. The VAVS technique should be differentiated from two other ways of using user's voice input, which have been actively explored in previous research: voice commands (in a broad sense, including voice-based queries) and multi-modal input techniques.

Like voice commands, which are an increasingly common interaction technique, for instance, in in-car systems [START_REF] Lau | Speech-activated user interfaces and climbing Mt. Exascale[END_REF], VAVS also employs users' voice input. Unlike voice commands, however, VAVS does not cause substantial changes in the state of the system. Its effect is limited to visually highlighting potential objects of interest. If a user's voice input results in highlighting some other object than the desired one (either because of a user's mistake or system's misinterpretation) the user can simply ignore the highlighting when proceeding with their task. It also means that VAVS users do not have to be overly concerned about negative consequences of their mistakes (while users of voice command systems have to overcome a substantial initial barrier before they start to feel comfortable with a system [START_REF] Lau | Speech-activated user interfaces and climbing Mt. Exascale[END_REF]).

A related approach to employing user's voice in human-computer interaction is supporting multi-modal input, or multi-modal dialogue, that is, enabling the use of voice input in combination with other interaction modalities [START_REF] Bolt | Put-that-there": Voice and gesture at the graphics interface[END_REF][START_REF] Nielsen | Voice Interfaces: Assessing the Potential[END_REF][START_REF] Voida | A study on the manipulation of 2D objects in a projector/camera-based augmented reality environment[END_REF]. An example of this approach is the classic "Put-that-there" system [START_REF] Bolt | Put-that-there": Voice and gesture at the graphics interface[END_REF], which combines voice and gesture. For instance, to move an object across a large display the user specifies a command by voice (i.e. by saying "put"), points to an object and selects it by saying "that", and finally indicates a new location by pointing to it and saying "there".

Voice recognition screen S microphone M

Memory representation of displayed objects

Users of the "Put-that-there" system, as well as users of more recent systems that implement the same general approach [START_REF] Voida | A study on the manipulation of 2D objects in a projector/camera-based augmented reality environment[END_REF], need to know-in advance-the spatial locations of objects of interest and convey these spatial locations to the system when instructing it to carry out a desired action. Support for selecting an object to indicate the system what it should act upon (cf. Windows Speech Recognition [START_REF]What can I do with Windows Speech recognition?[END_REF]) may partially overlap with support of visual search, but the general approach adopted by VAVS is, in a sense, opposite. According to that approach, it is the system that conveys the spatial locations of objects of interest to the user, rather than the other way around. Accordingly, a VAVS system has a number of features differentiating it from multimodal input systems. For instance, all potential objects of interest, rather than just potential objects of actions, should be "highlightable".

The next section presents a feasibility study intended to gain empirical evidence on whether VAVS can be helpful when supporting users in finding objects of interest on complex displays.

Method

Participants. Eight university students, native Swedish speakers and fluent English speakers, 23 to 33 years old, took part in the study.

Procedure. The participants were tested individually. Each session started with a profile calibration procedure that took five to twelve minutes. After that each participant was presented with a series of object location tasks. In each task a participant was presented with a name of a map region in the top left corner of the screen and was required to locate and click the corresponding map region using the mouse. The user had to click the correct map region to proceed to the next task. Each participant was presented with 96 object location tasks divided into two blocks. One of the blocks corresponded to the "VAVS" condition (voice input was enabled), and the other block corresponded to the "non-VAVS" condition (voice input was disabled). In each block the first five tasks were practice tasks, not included in the analysis. Finally, the participants were briefly interviewed about their experience with VAVS. The duration of a typical session with a participant was about 30 min.

Equipment. The hardware used in the study was an Apple MacBook Pro computer (15-inch, 2.33 GHz Intel Core 2 Duo processor, 4 GB SDRAM) running Mac OS X 10.6.3, connected to two external devices: Microsoft IntelliMouse Explorer 3.0 and Logitech USB Desktop Microphone.

Prototype. An interactive prototype of a VAVS-enabled system was developed for the study in AppleScript and JavaScript. The prototype was integrated with a speech recognition program, Nuance MacSpeech Dictate International, version 1.5.8. The visual interface was implemented as an HTML document opened in full screen mode.

The functionality of the prototype included: (a) displaying a map featuring a number of regions ("countries" or "states"), (b) displaying the name of one of the map regions in the top left corner of the screen, (c) measuring the time interval between presenting a name of a region and a mouse click on the corresponding map region, (d) recognizing a map region name uttered by the user, and (e) visually highlighting the map region corresponding to the name. In the control ("non-VAVS") condition functions (d) and (e) above were disabled.

Materials. Two maps, loosely based on Adobe Photoshop filter-generated images as reference for map region borders, were created for the study. Map A was derived from a map of Europe, and real English names of European countries were randomly assigned to different map regions (see Figure 2). Map B was derived, in a similar manner, from a US map.

The maps were designed to make sure the participants were familiar with the names of the map regions but could not use their previous knowledge to infer the locations of map regions from their names. Therefore, the participants had to visually scan the maps in order to complete the experimental tasks.

Fig. 2. An adapted fragment of Map A ("Liechtenstein" is visually highlighted).

Design. The study employed a one-factor within-subject design, with the independent variable being Voice Input ("VAVS" condition vs. "non-VAVS" condition). The main dependent variable was task completion time.

The design was balanced to minimize the potential effects of condition sequence and map types. The participants were divided into two equal sub-groups. The first sub-group completed the first block of tasks in the "VAVS" condition and the second block in the "non-VAVS" condition; for the second sub-group the sequence was the opposite. In each of these two sub-groups half of the participants worked with Map A in the "VAVS" condition and Map B in the "non-VAVS" condition, while for the other half the correspondence between maps and conditions was the opposite.

Results

As mentioned, the experiment procedure required a task to be correctly completed before the next task could be presented. All participants were able to complete all tasks in both conditions, which allowed us to use time to correctly complete a task as an integral performance indicator, in which error costs, both participants' mistake and voice recognition errors, were reflected as added "error time".

Voice recognition error rate in the VAVS condition-calculated as the percentage of tasks, in which the participants had to pronounce a state or country name more than once-was 19%. In two cases the experimenter had to intervene and suggest the right pronunciation (while the tasks were performed by the participants themselves). A likely reason for the high error rate was that native Swedish speakers were asked to pronounce English words.

Figure 3 shows accumulated times for completing blocks of tasks in the two experimental conditions for each of the eight participants. Figure 3a shows the results of the four participants (S1, S2, S3, and S4), who worked with Map A in the "VAVS" condition and Map B in the "non-VAVS" condition. Figure 3b shows the results of the four participants (S5, S6, S7, and S8), who worked with Map B in the "VAVS" condition and Map A in the "non-VAVS" condition. The results, shown in Figure 3, indicate that in the "VAVS" condition each of the participants completed the experimental tasks faster than in the "non-VAVS" condition. While the average accumulated task completion time in the "non-VAVS" condition was 384 seconds; in the "VAVS" condition it was 176 seconds.

The results were analyzed using the Wilcoxon signed-rank test. The difference between the "VAVS" and "non-VAVS" condition was found to be statistically significant (N=8, W + =36, W -=0, p=.005). In their interview comments all participants indicated that they were positive about the VAVS technique and wanted it to be used in a diversity of everyday contexts.

Discussion of results and future work directions

The results of our study suggest that employing user voice input for visually highlighting objects of interest can be associated with higher performance and positive user experience. Given that the use of voice at the user interface is complicated by a number of factors [START_REF] Benyon | Designing Interactive Systems: People, Activities, Contexts, Technologies[END_REF], and speech-based interfaces have been, in general, much less successful than it was anticipated in the past [START_REF] Manaris | Natural Language Processing: A Human-Computer Interaction Perspective[END_REF][START_REF] Nielsen | Voice Interfaces: Assessing the Potential[END_REF], we consider the results of our study encouraging. The study also showed that a standard speech recognition program can be accurate and reliable enough to support VAVS-enabled interaction.

It should be noted that advantages of VAVS were observed in conditions in which the advantages were not self-evident. The participants had to speak a foreign language, which was probably one of the reasons behind the high voice recognition error rate and, consequently, resulted in higher task completion times in the VAVS condition. In addition, the map image used in the study was relatively simple, which meant that unassisted visual search remained a viable option. It is reasonable to assume that if the users spoke their native language and worked with large displays and complex images, VAVS' advantages would be even more significant.

Can the findings be explained by a "negative familiarity" effect, that is, by target familiarity being an impediment rather than help in the specific task used in the study? If this explanation is correct, the findings from our study are only valid for rare instances of search tasks. However, the results do not support this hypothesis: if it were correct, the longest search time would be for "Sweden", which was participants' home country. In fact, the average search time for "Sweden" was shorter than for any other country name used in the experiment.

The study reported in this paper is a feasibility study, an initial phase of exploring the VAVS technique. Choosing unassisted visual search as a baseline for comparison was a natural choice for this first step. Further exploration of the technique is planned to compare VAVS with other types of visual search support, such as using text search strings for visually locating objects displayed on the screen. Other possible issues to be explored in future research are as follows:

Augmented reality applications. In augmented reality applications VAVS can be used to help people locate objects of interest in the physical environment. For instance, providing voice input to a wearable system that includes a head up display can help a supermarket customer locate a certain product on a shelf.

Using small screen devices to view large images. Visual search can be especially difficult if the user scans a large image (e.g., a map) using a small screen device, such as a smartphone. A variation of VAVS can be implemented to recognize user voice input and, if it matches an object, which is a part of the large image but not displayed in the small window, indicate the direction in which the window needs to be scrolled to display the object.

2D sound feedback. A potential problem with VAVS is that in case of very large, complex, and dynamic displays the visual highlighting produced by VAVS could be difficult to detect. A possible solution to this problem is to supplement visual highlighting with a 2D sound signal that would direct user's attention to the general spatial location of the object of interest.

Fig. 1 .

 1 Fig. 1. Overall structure of a VAVS-enabled interface.

Fig. 3a .Fig. 3b .

 3a3b Fig. 3a. Accumulated task completion times, in seconds, for the experimental conditions of the study. Participants: S1, S2, S3, and S4. "VAVS": Map A, "non-VAVS": Map B.