How is mobile task performance different? The case of information processing without information search

Studies have repeatedly highlighted the inferior performance of mobile users relative to that of personal computer (PC) users, largely due to lower usability and higher search costs arising from the use of smaller screens. Research, however, has yet to substantively address the situation in which mobile users perform tasks that require information processing without information search, implying an absence of device-related performance differences in such situations. Against this background, we propose that mobile task performance may be inferior in cognitive tasks, even when usability and search costs cannot be used as explanatory mechanisms, due to the predisposition of users to process information differently on different devices. We provide evidence in support of this proposition in two experiments. We find that mobile users perform worse (less accurately) than PC users do when the tasks demand high cognitive load. By contrast, when the tasks demand low cognitive load, performance is comparable across devices. We observe this interaction effect for different types of cognitive load - intrinsic and extraneous - despite their opposite effects on task performance. In so doing, we extend existing explanations of mobile task performance and shed light on the boundary conditions under which mobile use negatively affects task performance.