van Gog, T., Kester, L., Dirkx, K., Hoogerheide, V., Boerboom, J., & Verkoeijen, P. P. J. L. (2015). Testing After Worked Example Study Does Not Enhance Delayed Problem-Solving Performance Compared to Restudy. Educational Psychology Review, 27(2), 265–289

For high Element interactivity material (modestly complex problem solving), the authors fail to find a Testing effect and instead find a Worked example effect: restudying isomorphic worked examples leads to better results on final test performance. This holds both when the Retrieval practice involves solving isomorphic/identical problems and also when it involves simply recalling the text of the example solution.

This paper poses problems for How might the mnemonic medium support readers in building more complex understanding?.