Personification and Practical Dialogues in a Kiosk Agent

An Embodied Conversational Agent was used as an interactive information kiosk host and guide for a major technology conference. Content analysis of a log of user questions revealed that general conversational questions dominated the interactions rather than situationspecific requests for information, supporting the idea that users personify agents. The use of a general response data set is discussed as a means to facilitate the rapid development of personified intelligent agents. INTRODUCTION Software agents have been used in a variety of situations, often “replacing” the function of a human, such as tutor, greeter, web page host, interviewee, or “actor” in interactive simulations. Despite sometimes limited intelligence and language processing capabilities, agents often give the illusion that they are knowledgeable sources of information. The temporary suspension of belief that agents are not human is referred to as personification (Koda & Maes, 1996), and is attributed to the life-like combination of characteristics that an agent provides. While most users of agents realize that they are interacting with software rather than a real human, there is a tendency to treat computers and software agents as if they were actually human (Reeves & Nass, 1998; Lester, Converse, Kahler, Barlow, Stone, & Bhogal, 1997). Animated characters that look and behave in human-like ways raise expectations of human adaptation behavior (Andre & Rist, 2002). An embodied conversational agent (ECA) is a two-dimensional software representation of a human, hosted within a computer. Generally the term refers to an intelligent agent that has human-like elements to it, including graphical representation and conversational abilities (Cassell, 2000; Cassell, Bickmore, Campbell, Vilhjalmsson, & Yan, 2000). Most ECA have visual aspects to them, often consisting of a “talking head” or a head and shoulders image although full-bodied agents are also possible. Some ECA have the capability to react to spoken questions, while more commonly, they accept only text input. ECA typically have the ability to speak using synthesized voices of varying degrees of quality. Some agents are emotive, and can express feelings such as happiness or annoyance. An agent needs to be sufficiently conversational to perform required functions in its environment. A kiosk-based agent, for example, typically performs the tasks associated with an information booth in a public environment. In an information booth, visitors ask questions of a limited type and expect a focused, accurate response. This basic interactive structure is sometimes called a practical dialogue (Allen, Byron, Dzikovska, Ferguson, Galescu, & Stent, 2000). Basic human to human interaction requires the ability to decode input messages and to fashion mutually coherent responses to this input (Yacci, 2000). When humans work in an information booth, the ability to conduct conversational dialogue is a presumed prerequisite skill – and one that is common across most average adults. However, ECA must be carefully crafted to be able to carry out practical dialogues – the less constrained the dialogue, the more complex the agent must be Kiosk-based agents have been created previously in several contexts, although much of the testing of such systems has been limited to user tests in controlled situations. One of the few reported studies in the context of a public kiosk-based agent was described by Gustafson, Lundeberg, & Liljencrants (1999) whose agent August used the personality of 19 century author August Strindberg to assist people without supervision in a Cultural Center in Stockholm. August was programmed with information about local sites and also contained information about the persona of Strindberg, who was well known to local users. Using this ECA, researchers were able to gather experiences and information over a 6 month period. However, much of the reporting on August describes the technical aspects of the system or else the efforts toward realism (1999). Little is reported regarding the actual interactions that occurred in the context which the agent was employed. A similar kiosk-based agent, Max, was deployed at the Heinz Nixdorf Museums Forum to serve as a museum guide. Max engages visitors in conversation regarding the museum and its exhibits. Visitors use a keyboard to interface with Max, who responds in simulated voice. Several similar systems are reviewed briefly (Kopp, Gesellensetter, Krämer, & Wachsmuth, 2005), although generally speaking, these systems are often laboratory-based rather than publicly accessible. From Max, an initial list of actual questions from users in this kiosk context was reported. Context can be thought of as the situation and environment in which a user interacts with a technical system to accomplish a purpose. Several theories of context currently exist, such as activity theory, situated cognition, and distributed cognition. Nardi’s (1996) review of these theories shows that each depends upon understanding the activities of a user in a specific situation, and that these user activities are dependent upon and influenced by the performance environment and the nature of the tasks that are to be achieved. Thus, the way a user interacts with an agent will be influenced by the context in which the agent “exists. ” For example, computer-based telephone answering systems provide a context in which users are receive limited opportunities for communication. These systems usually have a system-directed conversation, in which the system provides options and the user is limited to selecting from these choices. A computer-based telephone system might, for example, provide the following practical dialogue: (“For assistance with parts, press 1; for assistance with sales, press 2; for hours of operation, press 3.”) When using these systems, users have limited expectations about the capacity of the systems, and expect to be guided through a series of “yes/no” questions, basic phone keypad input, or other simple interactions. The combination of tool, experience, task, and expectation create a context in which both user and dialogue system behave Each context indicates different expectations in the system users. Allen et. al (2000) suggest the practical dialogue hypothesis: conversational skill needed for practical dialogue systems can be created more simply than general human conversational competence. In other words, simpler conversational processes are effective in these systems because user expectations are somewhat lowered by the context of the system. In the context of an information booth or kiosk, it is expected that visitors will primarily be asking questions regarding location, times, features, and perhaps recommendations. Given the obvious computerized nature of the agent, the practical dialogue hypothesis would suggest that a user’s conversational expectations for the agent would be lower than that of an actual human. That is, people would not expect the agent to have the ability to react to the wide variety of questions that a human could. However, the idea of personification states that life-like agents create an illusion of reality due to the temporary suspension of belief that may occur, because the agent looks and behaves in a somewhat believable manner. This suggests that a personified agent would be more believable and that its users would expect more than simple practical dialogues. The persona effect was noted in students in an intelligent tutoring context (Lester, Converse, Kahler, Barlow, Stone, & Bhogal, 1997) in that it provided additional motivational benefits to students – perhaps similar to the way that a friend would provide motivation. It is possible that personification could impact users of a kiosk-based ECA, altering the types of questions that they might ask of the agent. This would impact the nature of the dialogue between agent and visitor, changing it from primarily functional (regarding the event or organization) to personal (regarding opinions, feelings, and personal history). QUESTION CATEGORIES General research on questioning behavior has a long history. Lehnert’s early work (1978) in computing and cognitive psychology and Graesser & Black’s work in AI (1985) both created categories and structures for generic question types. Specific investigations of questioning in a broad range of domains included stories, blocks, aircraft flight, medical diagnosis and travel systems. Despite the technical advances in graphics, input interfaces, and reasoning capabilities in agents, there are few empirical studies on actual human-agent communication in specific contexts. For example, when facing the task of creating and implementing an ECA in a practical, information-intensive capacity as a kiosk agent, there was little published guidance (beyond Max) as to what to expect from actual users in this particular situation; there is little empirical description of what users will say to agents in a kiosk capacity, with what frequency, and with what depth. Generalizing from the existing data is problematic due to the unpredictable effect of context. THE STUDY This study investigated the question: how do visitors at a technical festival communicate with a kiosk-based agent? This qualitative study was exploratory in nature, with the goal of developing more clear descriptions of the interactions in this context, which could guide future development of embodied conversational agents. To answer this question, the interactions between a kiosk-based ECA and multiple users were logged for the purpose of categorizing the types of interaction that an ECA carries out. An information kiosk agent was constructed and used at RIT’s Innovation and Creativity Festival, a one-day technology festival that attracts over 20,000 people. The “Banter with Bill” agent was developed to serve the function of an information kiosk at the festival. Bill was modeled after RIT’s President Bill Destler, w