It is important to measure progress and growth during the semester/unit, as well as at the end. The content linked here provides helpful information about formative assessment, the benefits of implementing it in your teaching, and different strategies that can be used.
Connecting Formative Assessment Research to Practice
American Institutes for Research, https://www.air.org/
Introductory guide to formative assessment, highlighting research findings, policies, practice options, and resources. A free downloadable PDF of the guide is available.
Examples of Formative Assessment
West Virginia Department of Education, wvde.state.wv.us
Information and clear explanations of a variety of formative assessment strategies, accompanied by links for further reading/exploration.