This article considers tools to support remote gesture in video systems being used to complete collaborative physical tasks-tasks in which two or more individuals work together manipulating three-dimensional objects in the real world. We first discuss the process of conversational grounding during collaborative physical tasks, particularly the role of two types of gestures in the grounding process: pointing gestures, which are used to refer to task objects and locations, and rep- HUMAN-COMPUTER INTERACTION, 2004, Volume 19, pp. 273-309 Copyright © 2004 resentational gestures, which are used to represent the form of task objects and the nature of actions to be used with those objects. We then consider ways in which both pointing and representational gestures can be instantiated in systems for remote collaboration on physical tasks. We present the results of two studies that use a "surrogate" approach to remote gesture, in which images are intended to express the meaning of gestures through visible embodiments, rather than direct views of the hands. In Study 1, we compare performance with a cursor-based 274 FUSSELL ET AL.

This study assessed the value of two video configurations-a head-mounted camera with eye tracking capability and a scene camera providing a view of the work environment-on remote collaboration on physical (3D) tasks. Pairs of participants performed five robot construction tasks in five media conditions: side-by-side, audio-only, head-mounted camera, scene camera, and scene plus head cameras. Task completion times were shortest in the side-by-side condition, and shorter with the scene camera than in the audio-only condition. Participants rated their work quality highest when side-by-side, intermediate with the scene camera, and worst in the audio-only and head-camera conditions. Similarly, helpers' self-rated ability to assist workers and pairs' communication efficiency were highest in the side-by-side condition, but significantly higher with the scene camera than in the audio-only condition. The results demonstrate the value of a shared view of the work environment for remote collaboration on physical tasks.

We explored anthropomorphism in people's reactions to a robot in social context vs. their more considered judgments of robots in the abstract. Participants saw a photo and read transcripts from a health interview by a robot or human interviewer. For half of the participants, the interviewer was polite and for the other half, the interviewer was impolite. Participants then summarized the interactions in their own words and responded true or false to adjectives describing the interviewer. They later completed a post-task survey about whether a robot interviewer would possess moods, attitudes, and feelings. The results showed substantial anthropomorphism in participants' interview summaries and truefalse responses, but minimal anthropomorphism in the abstract robot survey. Those who interacted with the robot interviewer tended to anthropomorphize more in the post-task survey, suggesting that as people interact more with robots, their abstract conceptions of them will become more anthropomorphic.

Information technologies have the potential to facilitate crosscultural collaboration, but this potential may be limited by different styles of IT use in different cultures. We report the results of a preliminary study and a larger follow-up study that focus on the use of Instant Messaging (IM) in North America and Asia. Consistent with the distinction between Western individualistic, low-context cultures and Eastern collectivistic, high-context cultures, we found that multi-party chat, audio-video chat and emoticons were much more popular in Asia than in North America. We conclude that cultural differences should be taken into consideration when designing tools for cross-cultural communication.

Supporting creativity via collaborative group brainstorming is a prevalent practice in organizations. Today's technology makes it easy for international and intercultural group members to brainstorm together remotely, but surprisingly little is known about how culture and medium shape the underlying brainstorming process. In a laboratory study, we examined the influences of individual cultural background (American versus Chinese), group cultural composition (same-versus mixed-culture groups), and communication medium (text-only versus video-enabled chatrooms) on group brainstorming conversations. Cultural differences and adaptation in conversational talkativeness and responsiveness were identified. The text-only medium reduced cultural differences in talkativeness. Working in a mixed-culture group led to cultural adaptation in the communication style of Chinese but not American participants. We discuss implications for international group brainstorming.

In this paper we describe a software tool that allows investigators to make comparisons across different online forums and media by analyzing word counts in userspecified categories. Using a large sample of messages from a bipolar support chatroom, we demonstrate how this tool can be used to characterize the nature of the discourse and compare it to other media, to analyze relationships among different word categories, and to characterize changes in visitors' discourse over time. Future plans for adding functionality to the software and using external data for additional validation are also discussed.

This study assessed the value of two video configurations-a head-mounted camera with eye tracking capability and a scene camera providing a view of the work environment-on remote collaboration on physical (3D) tasks. Pairs of participants performed five robot construction tasks in five media conditions: side-by-side, audio-only, head-mounted camera, scene camera, and scene plus head cameras. Task completion times were shortest in the side-by-side condition, and shorter with the scene camera than in the audio-only condition. Participants rated their work quality highest when side-by-side, intermediate with the scene camera, and worst in the audio-only and head-camera conditions. Similarly, helpers' self-rated ability to assist workers and pairs' communication efficiency were highest in the side-by-side condition, but significantly higher with the scene camera than in the audio-only condition. The results demonstrate the value of a shared view of the work environment for remote collaboration on physical tasks.

We present a study of the effects of instant messaging (IM) on individuals' management of work across multiple collaborative projects. Groups of four participants completed four web design tasks. Each participant worked on two tasks, each task with a different partner who was either co-located or remote, connected via IM. In one condition, each participant had one co-located and one remote partner. In a second condition, both partners were remote. We examined communication, division of labor, and task performance as a function of condition. The results indicated that nearly all participants divided their time unequally between projects, but less unequally in the remote/remote condition. In the co-located/remote condition, participants favored the task with the co-located partner. The results show that the effects of IM differ depending on people's multiple tasks are distributed across space. We propose a new IM interface that promotes awareness of multiple collaborators on multiple tasks.