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Home > Ask an Expert > How can I figure out how much a student has learned in a year?

Jim Hull, Senior Policy Analyst, Center for Public Education

How can I figure out how much a student has learned in a year?

A: Data can show how much students in a district are growing academically. Such data is calculated via a growth model, which provides data on how much students grew academically from one year to the next.

Yes, data can show how much students in a district are growing academically. Such data is calculated via a growth model that provides data on how much students grew academically from one year to the next. However, there is no one growth model. There are many different types, and each have their own purpose and provide specific data for that purpose.

 One such growth model that gets a lot of publicity is a value-added model. Keep in mind that value-added models are a specific type of growth model; not all growth models are value-added models. Value-added models are complex statistical models used to isolate the effect of a certain program, person, or school on the change in student achievement from one year to the next. For example, a value-added model is used to compare the academic gains made by students in one school to the gains similar students made in other schools in the state. (Experts do debate the extent to which value-added models are able to make these apples-to-apples comparisons.)

Unfortunately, not all districts have access to such data for a variety of reason. One, may be they don’t have the data systems to track individual students from year to year, which is essential to calculating growth data. Even if a district has the needed data systems in place, it may not have the statistical expertise in place to develop an accurate growth model or have the funding to outsource the development to outside experts.

Even in districts where growth data is available, you should ask yourself a few questions before using the data for important decisions:

  • What type of growth model is being used?
  • What is the model actually measuring?
  • What are the limitations of the model?
  • What is the model being used for (accountability, teacher/program evaluation, etc)?

Knowing the answers to these questions will enable you to make more effective decisions based on growth data. If growth data is not available in your district, here is a list of what is needed to implement a growth model.

To learn more, check out the Center’s easy-to-read Measuring Student Growth: A Guide to Informed Decision Making.  You can also learn more about using growth models in our Learning Center.