My research focuses on comprehensive evaluation of in vitro assays to improve the repeatability and interlaboratory agreement of the assay results. This could entail using cause-and-effect analysis to understand sources of variability in the assay, designing new plate layouts that include key process control measurements, and utilizing appropriate statistical analyses to understand the assay results and their uncertainties. This process should lead to improvements in the comparability and reproducibility of assay results within and between laboratories. Another source of ongoing research is how best to design in process control measurements such as the positive chemical control to maximize the confidence in the assay results. Overall, these efforts will help create a process for increasing measurement assurance for in vitro assays, facilitating their standardization and their use in adverse outcome pathway models.