Social navigation exploits social practices to help users navigate and explore system functionality. In a wireless world, people move around, meet others and experience places and situations. Those activities may be recorded and presented to others through wireless devices, and serve in social navigation. One design challenge is how to deal with the technical limits and ‘seams’ of such devices, such as gaps and breaks in functionality, imprecise positioning, and errors in recording and representation. Social navigation systems rely on recording and representing people's activity, and computational representation is affected by seams. We gained some insights into the way that social navigation and seams are socially constructed by analysing the functionality and social practice of three systems: GeoNotes, Hocman and the Seamful Game. We propose that social navigation and a ‘seamful design’ approach helps users take advantage of seams, appropriating and adapting system functionality for their own uses and interpretations.

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Social capital is defined as the set of connections among individuals-social networks and the expectation of generalized reciprocity and general trust that arise from them. In this paper, I investigate both the causes and the consequences of social capital supplied by the Internet, based upon the results of some social surveys. First, I review some research on the effect of the Internet use from the perspective of social psychology. Second, I demonstrate that social activities in online communities increase social capital. Third, concerning consequences, I examine whether the social capital offers benefits to individuals as well as the collective. The results suggest that the mobilization of social resources embedded in social networks in online communities increases psychological well-being and satisfaction in their decision-making. These results also show the possibility that activities in online communities may lead to empowerment and social resolution. Finally, I discuss some negative effects of social capital supplied by the Internet on both the micro-level and macro-level.

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Previous work on information foraging theory has addressed how people navigate through information systems to find information. This paper presents a new information foraging model called InfoCLASS that models the conceptual categories that people learn while interacting with information systems. InfoCLASS is based on previous work on the rational analysis of human category formation. InfoCLASS simulations can be used to make qualitative predictions about the richness of conceptual categories that will be learned from different experiential histories, and from different kinds of user interfaces. InfoCLASS simulations can also be used to predict the conceptual consensus among a group of users of information systems. It is argued that the degree of conceptual coherence among a group of users is an important determinant of the efficiency and effectiveness of a social organization engaged in making discoveries, such as scientific communities.

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A series of analyses on the dynamics of participation in face-to-face multi-party conversations were conducted to demonstrate that the centrality of participation in a conversation is correlated with participants' interest in objects discussed as the topics of the conversation. The correlation can be exploited for Social Navigation in real world human interactive situations.
Exploitation of behavioral histories of others is an important strategy for effective problem solving. By accumulating a volume of ‘word of mouth’ information, a number of recommendation systems have been developed and deployed on the basis of this idea to facilitate searching on the Web for objects that match with people's personal tastes. Furthermore, recent advance in ubiquitous computing technologies is making it possible to collect the same types of information in real world settings.
This paper focuses its attention on the possible cues for Social Navigation which are available from human interactive conversational behaviors. Based on a dynamic transition model of participation roles in conversations, a hypothesis was presented that the more central a role one plays in a conversation, the more highly interested she is in the topic of conversation. The hypothesis was then tested and confirmed through analyses of human interaction behaviors in experimental poster presentation sessions. The analyses revealed that (a) the frequency of interaction with exhibitors was a good indicator of visitors' interest in the corresponding posters, (b) interest in the posters was proportionate with the time visitors spent being directly addressed by exhibitors rather than as side-participants, and (c) addressee-hood of visitors manifested itself in the coordinated production of verbal backchannel responses.
These results suggest that interactional cues for conversational participation structures can effectively be utilized as a measure of human interest. Since collection of conversational behavior cues does not incur any additional burden on users, it has a wide application possibilities for Social Navigation in the ubiquitous society.

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In the present study, we experimentally clarified whether assessing other-generated hypotheses could facilitate hypothesis revision using a rule-discovery task. In the first phase, participants were asked either to generate their own hypotheses and assess them or to evaluate the hypotheses presented as other-generated hypotheses. In the second phase, all participants were required to generate their own hypotheses and evaluate their plausibility. The results showed that participants who assessed the other-generated hypotheses prior to generating and assessing their own hypotheses produced better performance than those who generated their own hypotheses and assess them thoroughly. In addition, while confidence on their own hypotheses became slightly higher as the participants saw instances in the Self-generated hypothesis condition, confidence on the hypotheses became lower in the Other-generated hypothesis condition. It was concluded that the source of hypotheses affected the confidence on the hypothesis, especially after the participants faced the counterevidence. In other words, other-generated hypotheses were less confident than self-generated ones after the data inconsistent with the hypotheses was presented, which enabled the participants to revise hypotheses more easily in the other-generated hypothesis condition than in the self-generated hypothesis condition.

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Pieces of information and cues left by other people's actions often help us in our daily problem solving activities. In this paper, we examined the roles and functions of HARIGAMI, or stickers, from the viewpoint of social navigation. We collected 1075 pieces of HARIGAMI from 1998 to 2004. We categorized them into cognitive and social categories, and described the situations in which these HARIGAMI were used.
The results indicate that HARIGAMI conveys such information as (1) traces of other people's activities, (2) most frequent uses of functions of the system on which HARIGAMI are added, and (3) environmental and system changes as time passes. By analyzing which cognitive level HARIGAMI worked on, we propose possible considerations on the refinement of the system design.
HARIGAMI also works as a medium of indirect communication between users of the system on which the HARIGAMI is attached. From analysis of HARIGAMI, we need a new communication channel between users of information distributed via HARIGAMI as it can be useful to prospective users of the system.

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In this paper, the technique for extracting user's interests implicit in E-mails and recommending with surprisingness by presenting unexpected contents is proposed. We discover two effective measures for extracting such interests through some experiments. One is the number of the times a user sent for selecting interesting Topics and the other is the modified tf · idf value for selecting interesting words. A Web page recommendation system which applies this technique is also introduced. This system can guide a user ahead towards unexpected contents which are not limited in the specific domain.

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In this study, we deal with the issue of searching for missing belongings that are used in our daily life. This study is regarded as a model case of a trial for integrating laboratory studies in cognitive psychology and understandings of human cognition and behavior in complex real situations. The search for missing belongings is experienced by everyone, and a typical problem solving behavior performed in a social context. We investigate this issue based on the framework of human problem solving, focusing on the similarity between the search process of missing belongings and the process of insight problem solving. We also try to explain why we feel serious difficulties in the search from a viewpoint of search for problem space. We explain the difficulties based on the dilemma existing between a depth-first search for a currently searching problem space and a shift of search to another problem space.

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To examine the communication mechanism of emotional valence in the written language, three experiments were conducted. In Experiment 1, subjects were asked to write sentences using appropriate script types (Kanji, Hiragana or Katakana) to communicate one of the three nuances (strict, light and modern) properly. Results showed that Kanji was used predominantly in the sentences with strict nuance than in the sentences with light or modern nuance, and that Hiragana was selected more in the sentences with light nuance. Katakana was used more in the sentences with modern nuance.
Experiment 2-1 examined if not only the script type but also the font type contribute to communicate emotional valence in the written language. The results by correspondent and cluster analyses indicated that different font types also had distinctive emotional meanings. In Experiment 2-2, subjects were asked to choose the appropriate font-script type that can express the image of a famous person well. Results showed the effects of compatibility between the mental representation of famous person and emotional-semantic images of the font and / or script types.
Based on these results, the possibility that the emotional information can be communicated by the mechanism of choosing font and / or script types in written language as well as prosody in spoken language was discussed.

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Creole is one of the main topics in the fields concerning the language change and evolution, such as sociolinguistics, the developmental psychology of language and so on. Our purpose in this paper is to develop an evolutionary theory of language to study the emergence of creole. We discuss how the emergence of creole is dealt with regard to population dynamics. We modify the language dynamics equations by Komarova et al., so as to include the generation parameter ‘t’. From the viewpoint of the population dynamics, we give the definition of creole as a language, which is predefined by the universal grammar together with pre-existing languages. We show experimental results, in which we could observe the emergence of creole. Furthermore, we analyze the condition of creolization in terms of similarity among languages.

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The purpose of this study was to examine changes in confidence rating from a phenomenological approach. In experiment, participants (N=12) were required to perceive rod length by haptic touch without vision and to rate their confidence level in each trial. One group transformed their exploratory movement for length perception from dynamic touch to static holding, and another group did the same thing but in inverse order. Result showed that dynamic touch could perceive the actual extent accurately than static holding, and that the transition from dynamic touch to static holding made participants have less confidence on their perception, but the reverse transition had no effect. It was discussed that change in confidence would have context-dependent characteristics, considering the idea of coherence.

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