In the experiment, after a baseline assessment, participants will be assigned to one of two conditions (between-subjects factor). In condition A, I expect their response time to be higher in large stimuli than in small stimuli, but slower in colored stimuli than in b/w stimuli compared to their baseline performance and the opposite pattern in Condition B (slower response times in large trials, quicker response times in colored trials). So basically, I have the following factors: condition (A and B), stimulus feature slowing (slowing due to color, slowing due to size). At the same time, I would like to control for or consider participants' baseline performance (if adequate?). I am very unsure about how to analyze the data to test the hypothesized pattern adequately and to control for the baseline performance, is an expert here who could give me a hint? My initial idea was a 2x2 ANCOVA (Condition x Stimulus Feature Slowing, controling for baseline Color Slowing and baseline Size Slowing), but maybe a regression or a mulilevel regression or an entirely different analysis would be more adequate? Thanks a lot in advance.