I’ve seen this study on the effectiveness of different study techniques reported in a number of ways in the press. One example comes from Annie Paul Murphy here.
The original article is much more cautious in the conclusions it draws – pointing out that techniques it rated as having low or medium efficacy depended very much on the skill of the learner, the context of the learning (e.g. a few days or weeks before a test) and the material being learnt. Whilst it’s quite long, it does represent some interesting evidence on the effectiveness of various study techniques and could lend itself easily to a small research project with our classes: