20 formative assessment examples to use in your online classroom — from tophat.com
Informal assessments are an easy way to stay connected with your students and understand their progress in your course

Excerpt:

As learning environments evolve to incorporate online and remote learning, so too has the need for different approaches that provide flexibility in assessing students in-class, online or in blended learning environments. The following examples of formative assessment techniques can not only help you share more regular, reliable and useful feedback on student progress, they can also help you get started in thinking of other formative assessment strategies to incorporate into your lesson plans.