Stereotyped movements displayed by 6 participants and tics displayed by 6 children were evaluated using an antecedent behavioral analysis and a force sensitive platform. We found that tics occurred more often in an alone condition when compared to high preference toy and play conditions, whereas stereotyped movements were more variable across conditions. Using temporal measures and spectral analysis data from the force sensitive platform, we found that stereotyped movements tended to be longer in duration and displayed more rhythmic qualities when compared to tics. Results indicate that stereotyped movements and tics differ both quantitatively and qualitatively and support the use of new technologies, such as force plate technology, to more accurately evaluate these differences.