Date of Award


Degree Type


Degree Name

Master of Science (MS)


Psychological Sciences

Committee Chair

Richard Schweickert

Committee Member 1

Robert W. Proctor

Committee Member 2

Sebastien Hélie


Processing trees are widely used to model the accuracy in tasks. For the mental process of a task, people’s responses can be analyzed in terms of response probabilities and reaction time. Our project is to include reaction times in processing trees. Given a processing tree, if two sets of parameter values lead to the same predictions for response probabilities and response times, then there are equations relating parameter values in one set to those in the other set. We derived these equations and calculated relevant degrees of freedom. The current study also includes results on the following topics: the restricting conditions for the nonnegativity of time parameters, mixtures of trees with factors selectively influencing processes, and conditions under which an arbitrary processing tree is equivalent to the Standard Binary Tree for Ordered Processes.