Behavior Research Methods, Instruments, & Computers

, Volume 28, Issue 3, pp 427-445

First online:

RTSYS: A DOS application for the analysis of reaction time data

  • Andrew HeathcoteAffiliated withPsychology Department, University of Newcastle


RTSYS is a menu-driven DOS application for the manipulation, analysis, and graphical display of reaction time data. It can be used either in a single-task environment under DOS, with access to a set operating system commands, or as an application under Windows. All functions have context-sensitive help. RTSYS fits the ex-Gaussian distribution to reaction time data without the difficulties usually associated with numerical parameter estimation. Distribution fitting and flexible censoring and rescaling options allow RTSYS to address the problems of reaction time distribution skew and outlying responses with reasonable sample sizes. RTSYS can automatically process multiple input files from experiments with arbitrary designs and produce formatted output of statistics for further processing by graphical and inferential statistical packages. The present article reviews and explains techniques used by RTSYS and provides an overview of the operation of the program.