{Reference Type}: Evaluation Study {Title}: The Neurosphere Simulator: An educational online tool for modeling neural stem cell behavior and tissue growth. {Author}: Zupanc GKH;Lehotzky D;Tripp IP; {Journal}: Dev Biol {Volume}: 469 {Issue}: 0 {Year}: 01 2021 1 {Factor}: 3.148 {DOI}: 10.1016/j.ydbio.2020.09.016 {Abstract}: Until very recently, distance education, including digital science labs, served a rather small portion of postsecondary students in the United States and many other countries. This situation has, however, dramatically changed in 2020 in the wake of the COVID-19 pandemic, which forced colleges to rapidly transit from face-to-face instructions to online classes. Here, we report the development of an interactive simulator that is freely available on the web (http://neurosphere.cos.northeastern.edu/) for teaching lab classes in developmental biology. This simulator is based on cellular automata models of neural-stem-cell-driven tissue growth in the neurosphere assay. By modifying model parameters, users can explore the role in tissue growth of several developmental mechanisms, such as regulation of mitosis or apoptotic cell death by contact inhibition. Besides providing an instantaneous animation of the simulated development of neurospheres, the Neurosphere Simulator tool offers also the possibility to download data for detailed analysis. The simulator function is complemented by a tutorial that introduces students to computational modeling of developmental processes.