The proactive and spontaneous delivery of Web services for users on the move can lead to the depletion of their cognitive resources, affecting the normal processes of their physical activities. This is due to the competition for limited cognitive resources between the human-computer interactions required by Web services and the users’ physical activities. This paper introduces a mechanism for binding and scheduling Web services based on an assessment of this competition for
users on the move. The proposed approach is built on two
theories from cognitive psychology. This mechanism is realized
by a descriptive model of activities and Web services which is
enriched with a cognitive layer. A computational model uses this description to assess the degree of the demand for cognitive resources by both the physical activities and the Web services. Additionally, a Web services coordination mechanism based on this level of demand, the principle of progressive disclosure, and the temporal concurrency of Web services ensures less cognitively taxing Web service compositions.