What is the right sort of testing?

Interesting article about testing in the New York times, which argues that the effort of retrieving information helps learning. Marcia Linn’s comment is relevant to the Illustrative Mathematics Project:

“More testing isn’t necessarily better,” said Dr. Linn, who said her work with California school districts had found that asking students to explain what they did in a science experiment rather than having them simply conduct the hands-on experiment — a version of retrieval practice testing — was beneficial. “Some tests are just not learning opportunities. We need a different kind of testing than we currently have.”