A new and very interesting approach to the analysis of responses and response times is proposed by Goldhammer (this issue). In his approach, differences in the speed-ability compromise within respondents are considered to confound the differences in ability between respondents. These confounding effects of speed on the inferences about ability can be controlled for in experimental settings. As a result, the data for psychological or educational inferences consists of the response vectors only. Molenaar argues that the natural variability in response times can give valuable information for psychological and educational inferences about response processes and solution strategies, but that the approach by Goldhammer is very valuable if a single process or strategy needs to be measured in isolation.