Selective influence and response time cumulative distribution functions inserial-parallel task networks

We analyze sets of mental processes, some of which are concurrent and some of which are sequential, under the assumption that the processes are partia lly ordered, that is, arranged in a directed acyclic network. Information a bout the process arrangement can be discovered by examining the effects on response time of selectively influencing process durations. Previous work h as mainly focused on analyses of mean response times. Here we consider anal yses based on cumulative distribution functions, for one of the major class es of directed acyclic networks, serial-parallel networks. When two process es are selectively influenced, patterns in the cumulative distribution func tions can be used to test whether the processes are sequential or concurren t and whether the task network has AND gates or OR gates. Cumulative distri bution functions are potentially more informative than means, and some prev ious results for means are shown to follow from our results for cumulative distribution functions. (C) 2000 Academic Press.