%0 Journal Article %T Social Indispensability in Spite of Temporal and Spatial Separation: Motivation Gains in a Sequential Task During Anonymous Cooperation on the Internet %A Marion Wittchen %A Daniel Schlereth %A Guido Hertel %J International Journal of Internet Science %D 2007 %I University of Zurich %X Recent research has demonstrated motivation gains during synchronous group work compared to individual work when group members¡¯ contribution was indispensable for the group¡¯s success (e.g., Hertel, Kerr, & Mess¨¦, 2000, Hertel, Deter, & Konradt, 2003). The current study extends this earlier research (a) by examining indispensability effects during sequential cooperation (temporal separation), and (b) by exploring these effects under conditions of high anonymity on the Internet (spatial separation). A 2 (Internet vs. laboratory context) x 3 (high vs. low vs. no impact of personal contribution for a group) x 2 (individual vs. group trial) design was used with the last factor measured within subjects (N = 231). Motivation was measured with a vigilance task that simulated an Internet travel agency selling package holidays according to incoming customer requests. During all trials, participants received contemporaneous feedback about their own performance. During the group trials, participants additionally received information about their partner¡¯s alleged previous performance at this point of the trial, which suggested that the partner had always performed slightly better than the participant. As expected, both in the laboratory and the Internet setting, the highest motivation gains occurred when participants¡¯ contribution to the group¡¯s outcome was indispensable for the group. This finding provides evidence that motivation gains among inferior group members are possible even during sequential group work under highly anonymous conditions. %K group %K performance %K motivation gain %K social indispensability %K online experiment %U http://www.psychologie.unizh.ch/sowi/reips/ijis/ijis2_1/ijis2_1_wittchen.html