Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems
Publisher: ACM Press
Series: Part of the ACM SIGCHI CHI - Human Factors in Computing Systems conference series.
The annual CHI conference is the leading international forum for the exchange of ideas and information about human-computer interaction (HCI).
Date held: April 5-10, 2008
Full-text articles: Articles from this conference are available from the ACM Digital Library (requires subscription)
References from this conference
The following articles are from "Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems":
Articles
p. 1-10
Harboe, Gunnar, Metcalf, Crysta J., Bentley, Frank, Tullio, Joe, Massey, Noel and Romano, Guy (2008): Ambient social tv: drawing people into a shared experience. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1-10. Available online
p. 1009-1012
Zhou, Daniel Xiaodan, Oostendorp, Nathan, Hess, Michael and Resnick, Paul (2008): Conversation pivots and double pivots. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1009-1012. Available online
p. 1013-1016
Kamvar, Maryam and Baluja, Shumeet (2008): Query suggestions for mobile search: understanding usage patterns. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1013-1016. Available online
p. 1017-1026
Guy, Ido, Jacovi, Michal, Shahar, Elad, Meshulam, Noga, Soroka, Vladimir and Farrell, Stephen (2008): Harvesting with SONAR: the value of aggregating social network information. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1017-1026. Available online
p. 1027-1036
Joinson, Adam N. (2008): Looking at, looking up or keeping up with people?: motives and use of Facebook. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1027-1036. Available online
p. 103-106
Birnholtz, Jeremy, Mak, Clarissa, Greenberg, Saul and Baecker, Ronald M. (2008): Attention by proxy? issues in audience awareness for webcasts to distributed groups. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 103-106. Available online
p. 1037-1040
Suh, Bongwon, Chi, Ed H., Kittur, Aniket and Pendleton, Bryan A. (2008): Lifting the veil: improving accountability and social transparency in Wikipedia with wikidashboard. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1037-1040. Available online
p. 1041-1044
Thom-Santelli, Jennifer, Muller, Michael J. and Millen, David R. (2008): Social tagging roles: publishers, evangelists, leaders. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1041-1044. Available online
p. 1045-1054
Stoll, Jennifer, Tashman, Craig S., Edwards, W. Keith and Spafford, Kyle (2008): Sesame: informing user security decisions with system visualization. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1045-1054. Available online
p. 1055-1064
Sankarpandian, Kandha, Little, Travis and Edwards, W. Keith (2008): Talc: using desktop graffiti to fight software vulnerability. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1055-1064. Available online
p. 1065-1074
Egelman, Serge, Cranor, Lorrie Faith and Hong, Jason (2008): You've been warned: an empirical study of the effectiveness of web browser phishing warnings. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1065-1074. Available online
p. 107-110
Mark, Gloria, Gudith, Daniela and Klocke, Ulrich (2008): The cost of interrupted work: more speed and stress. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 107-110. Available online
p. 1075-1084
Tseng, Yuan-Chi and Howes, Andrew (2008): The adaptation of visual search strategy to expected information gain. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1075-1084. Available online
p. 1085-1088
O'Donovan, John, Smyth, Barry, Gretarsson, Brynjar, Bostandjiev, Svetlin and Höllerer, Tobias (2008): PeerChooser: visual interactive recommendation. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1085-1088. Available online
p. 1089-1092
Shami, N. Sadat, Ehrlich, Kate and Millen, David R. (2008): Pick me!: link selection in expertise search results. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1089-1092. Available online
p. 1093-1096
Ehrlich, Kate and Shami, N. Sadat (2008): Searching for expertise. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1093-1096. Available online
p. 1097-1100
Nov, Oded, Naaman, Mor and Ye, Chen (2008): What drives content tagging: the case of photos on Flickr. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1097-1100. Available online
p. 11-20
Wyche, Susan P., Aoki, Paul M. and Grinter, Rebecca E. (2008): Re-placing faith: reconsidering the secular-religious use divide in the United States and Kenya. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 11-20. Available online
p. 1101-1110
Butler, Brian, Joyce, Elisabeth and Pike, Jacqueline (2008): Don't look now, but we've created a bureaucracy: the nature and roles of policies and rules in wikipedia. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1101-1110. Available online
p. 111-120
Greenberg, Saul and Buxton, Bill (2008): Usability evaluation considered harmful (some of the time). In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 111-120. Available online
p. 1111-1120
Baumer, Eric, Sueyoshi, Mark and Tomlinson, Bill (2008): Exploring the role of the reader in the activity of blogging. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1111-1120. Available online
p. 1121-1124
Gill, Alastair J., Gergle, Darren, French, Robert M. and Oberlander, Jon (2008): Emotion rating from short blog texts. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1121-1124. Available online
p. 1125-1128
Kramer, Adam D. I. and Rodden, Kerry (2008): Word usage and posting behaviors: modeling blogs with unobtrusive data collection methods. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1125-1128. Available online
p. 1129-1138
Parkes, Amanda J., Raffle, Hayes Solos and Ishii, Hiroshi (2008): Topobo in the wild: longitudinal evaluations of educators appropriating a tangible interface. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1129-1138. Available online
p. 1139-1148
Bach, Kenneth Majlund, Jæger, Mads Gregers, Skov, Mikael B. and Thomassen, Nils Gram (2008): You can touch, but you can't look: interacting with in-vehicle systems. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1139-1148. Available online
p. 1149-1152
Müller-Tomfelde, Christian and Schremmer, Claudia (2008): Touchers and mousers: commonalities and differences in co-located collaboration with multiple input devices. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1149-1152. Available online
p. 1153-1156
Goldberg, Joseph H., Helfman, Jonathan I. and Martin, Lynne (2008): Information distance and orientation in liquid layout. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1153-1156. Available online
p. 1157-1166
Bellotti, Victoria, Begole, Bo, Chi, Ed H., Ducheneaut, Nicolas, Fang, Ji, Isaacs, Ellen, King, Tracy, Newman, Mark W., Partridge, Kurt, Price, Bob, Rasmussen, Paul and Roberts, Michael (2008): Activity-based serendipitous recommendations with the Magitti mobile leisure guide. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1157-1166. Available online
p. 1167-1176
Schnädelbach, Holger, Egglestone, Stefan Rennick, Reeves, Stuart, Benford, Steve, Walker, Brendan and Wright, Michael (2008): Performing thrill: designing telemetry systems and spectator interfaces for amusement rides. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1167-1176. Available online
p. 1177-1186
O'Hara, Kenton (2008): Understanding geocaching practices and motivations. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1177-1186. Available online
p. 1187-1196
Kay, Bonnie Ma and Watters, Carolyn (2008): Exploring multi-session web tasks. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1187-1196. Available online
p. 1197-1206
Adar, Eytan, Teevan, Jaime and Dumais, Susan (2008): Large scale analysis of web revisitation patterns. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1197-1206. Available online
p. 1207-1216
Morris, Dan, Morris, Meredith Ringel and Venolia, Gina (2008): SearchBar: a search-centric web history for task resumption and information re-finding. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1207-1216. Available online
p. 121-130
Guo, Cheng and Sharlin, Ehud (2008): Exploring the use of tangible user interfaces for human-robot interaction: a comparative study. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 121-130. Available online
p. 1217-1226
Isenberg, Petra, Tang, Anthony and Carpendale, Sheelagh (2008): An exploratory study of visual information analysis. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1217-1226. Available online
p. 1227-1236
Balakrishnan, Aruna D., Fussell, Susan R. and Kiesler, Sara (2008): Do visualizations improve synchronous remote collaboration?. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1227-1236. Available online
p. 1237-1246
Shrinivasan, Yedendra Babu and Wijk, Jarke J. van (2008): Supporting the analytical reasoning process in information visualization. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1237-1246. Available online
p. 1247-1256
Findlater, Leah and McGrenere, Joanna (2008): Impact of screen size on performance, awareness, and user satisfaction with adaptive graphical user interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1247-1256. Available online
p. 1257-1266
Gajos, Krzysztof Z., Wobbrock, Jacob O. and Weld, Daniel S. (2008): Improving the performance of motor-impaired users with automatically-generated, ability-based interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1257-1266. Available online
p. 1267-1270
Findlater, Leah, Grenere, Joanna M. and Modjeska, David (2008): Evaluation of a role-based approach for customizing a complex development environment. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1267-1270. Available online
p. 1271-1274
Gajos, Krzysztof Z., Everitt, Katherine, Tan, Desney S., Czerwinski, Mary and Weld, Daniel S. (2008): Predictability and accuracy in adaptive user interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1271-1274. Available online
p. 1275-1284
Moscovich, Tomer and Hughes, John F. (2008): Indirect mappings of multi-touch input using one and two hands. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1275-1284. Available online
p. 1285-1294
Peltonen, Peter, Kurvinen, Esko, Salovaara, Antti, Jacucci, Giulio, Ilmonen, Tommi, Evans, John, Oulasvirta, Antti and Saarikko, Petri (2008): It's Mine, Don't Touch!: interactions at a large multi-touch display in a city centre. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1285-1294. Available online
p. 1295-1298
Shi, Kang, Irani, Pourang, Gustafson, Sean and Subramanian, Sriram (2008): PressureFish: a method to improve control of discrete pressure-based input. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1295-1298. Available online
p. 1299-1302
Murray-Smith, Roderick, Williamson, John, Hughes, Stephen and Quaade, Torben (2008): Stane: synthesized surfaces for tactile input. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1299-1302. Available online
p. 1303-1312
Li, Yang and Landay, James A. (2008): Activity-based prototyping of ubicomp applications for long-lived, everyday human activities. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1303-1312. Available online
p. 131-140
Yamazaki, Akiko, Yamazaki, Keiichi, Kuno, Yoshinori, Burdelski, Matthew, Kawashima, Michie and Kuzuoka, Hideaki (2008): Precision timing in human-robot interaction: coordination of head movement and utterance. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 131-140. Available online
p. 1313-1322
Lin, James and Landay, James A. (2008): Employing patterns and layers for early-stage design and prototyping of cross-device user interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1313-1322. Available online
p. 1323-1332
Lawrance, Joseph, Bellamy, Rachel, Burnett, Margaret and Rector, Kyle (2008): Using information scent to model the dynamic foraging behavior of programmers in maintenance tasks. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1323-1332. Available online
p. 1333-1342
Elmqvist, Niklas, Henry, Nathalie, Riche, Yann and Fekete, Jean-Daniel (2008): Melange: space folding for multi-focus interaction. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1333-1342. Available online
p. 1343-1352
Pietriga, Emmanuel and Appert, Caroline (2008): Sigma lenses: focus-context transitions combining space, time and translucence. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1343-1352. Available online
p. 1353-1356
Dachselt, Raimund, Frisch, Mathias and Weiland, Markus (2008): FacetZoom: a continuous multi-scale widget for navigating hierarchical metadata. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1353-1356. Available online
p. 1357-1360
Jiang, Hao, Wigdor, Daniel, Forlines, Clifton, Borkin, Michelle, Kauffmann, Jens and Shen, Chia (2008): LivOlay: interactive ad-hoc registration and overlapping of applications for collaborative visual exploration. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1357-1360. Available online
p. 1361-1370
Fitzmaurice, George W., Matejka, Justin, Khan, Azam, Glueck, Mike and Kurtenbach, Gordon (2008): PieCursor: merging pointing and command selection for rapid in-place tool switching. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1361-1370. Available online
p. 1371-1380
Tian, Feng, Xu, Lishuang, Wang, Hongan, Zhang, Xiaolong, Liu, Yuanyuan, Setlur, Vidya and Dai, Guozhong (2008): Tilt menu: using the 3D orientation information of pen devices to extend the selection capability of pen-based user interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1371-1380. Available online
p. 1381-1384
Tanvir, Erum, Cullen, Jonathan, Irani, Pourang and Cockburn, Andy (2008): AAMU: adaptive activation area menus for improving selection in cascading pull-down menus. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1381-1384. Available online
p. 1385-1388
Matsui, Shouichi and Yamada, Seiji (2008): Genetic algorithm can optimize hierarchical menus. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1385-1388. Available online
p. 1389-1398
Li, Kevin A., Baudisch, Patrick and Hinckley, Ken (2008): Blindsight: eyes-free access to mobile phones. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1389-1398. Available online
p. 1399-1408
Karlson, Amy K. and Bederson, Benjamin B. (2008): One-handed touchscreen input for legacy applications. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1399-1408. Available online
p. 1409-1418
Rohs, Michael and Oulasvirta, Antti (2008): Target acquisition with camera phones when used as magic lenses. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1409-1418. Available online
p. 141-144
Jacobsson, Mattias, Bodin, Johan and Holmquist, Lars Erik (2008): The see-Puck: a platform for exploring human-robot relationships. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 141-144. Available online
p. 1419-1428
Oleksik, Gerard, Frohlich, David M., Brown, Lorna M. and Sellen, Abigail (2008): Sonic interventions: understanding and extending the domestic soundscape. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1419-1428. Available online
p. 1429-1438
Gaver, William W., Boucher, Andy, Law, Andy, Pennington, Sarah, Bowers, John, Beaver, Jacob, Humble, Jan, Kerridge, Tobie, Villar, Nicholas and Wilkie, Alex (2008): Threshold devices: looking out from the home. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1429-1438. Available online
p. 1439-1442
McGee-Lennon, Marilyn Rose (2008): Requirements engineering for home care technology. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1439-1442. Available online
p. 1443-1452
Grammenos, Dimitris (2008): Game over: learning by dying. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1443-1452. Available online
p. 145-154
Costabile, Maria F., Angeli, A. De, Lanzilotti, Rosa, Ardito, Carmelo, Buono, Paolo and Pederson, Thomas (2008): Explore! possibilities and challenges of mobile learning. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 145-154. Available online
p. 1453-1462
Pinelle, David and Wong, Nelson (2008): Heuristic evaluation for games: usability principles for video game design. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1453-1462. Available online
p. 1463-1472
Szentgyorgyi, Christine, Terry, Michael and Lank, Edward (2008): Renegade gaming: practices surrounding social use of the Nintendo DS handheld gaming system. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1463-1472. Available online
p. 1473-1482
Reeder, Robert W., Bauer, Lujo, Cranor, Lorrie Faith, Reiter, Michael K., Bacon, Kelli, How, Keisha and Strong, Heather (2008): Expandable grids for visualizing and authoring computer security policies. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1473-1482. Available online
p. 1483-1492
McLachlan, Peter, Munzner, Tamara, Koutsofios, Eleftherios and North, Stephen (2008): LiveRAC: interactive visual exploration of system management time-series data. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1483-1492. Available online
p. 1493-1496
O'Connell, Theresa A. and Choong, Yee-Yin (2008): Metrics for measuring human interaction with interactive visualizations for information analysis. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1493-1496. Available online
p. 1497-1500
Vertanen, Keith and Kristensson, Per-Ola (2008): On the benefits of confidence visualization in speech recognition. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1497-1500. Available online
p. 1501-1510
Miaskiewicz, Tomasz, Sumner, Tamara and Kozar, Kenneth A. (2008): A latent semantic analysis methodology for the identification and creation of personas. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1501-1510. Available online
p. 1511-1520
McQuiggan, Scott W., Rowe, Jonathan P. and Lester, James C. (2008): The effects of empathetic virtual characters on presence in narrative-centered learning environments. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1511-1520. Available online
p. 1521-1524
McGinn, Jennifer (Jen) and Kotamraju, Nalini (2008): Data-driven persona development. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1521-1524. Available online
p. 1525-1534
Heyer, Clint, Brereton, Margot and Viller, Stephen (2008): Cross-channel mobile social software: an empirical study. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1525-1534. Available online
p. 1535-1544
Kang, Sin-Hwa, Watt, James H. and Ala, Sasi Kanth (2008): Social copresence in anonymous social interactions using a mobile video telephone. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1535-1544. Available online
p. 1545-1554
Geyer, Werner, Dugan, Casey, DiMicco, Joan, Millen, David R., Brownholtz, Beth and Muller, Michael J. (2008): Use and reuse of shared lists as a social content type. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1545-1554. Available online