As online education becomes common, it is essential to identify activities that support critical thinking in this environment. This paper describes the use of a model-eliciting activity (MEA) solved by groups in a synchronous online discussion. The participants displayed their thinking processes and solutions consistent with successful face-to-face (F2F) MEAs. Each group’s discussion showed evidence of critical thinking and incorporated quality logical arguments. This demonstrates that MEAs may be also used in an online environment to successfully support application of critical thinking skills.