When my Geometry students are learning to apply concepts involving radicals, proportions, similarity, and right-triangle trigonometry, they need a lot of assistance from me and other students. Before giving them a summative assessment, I like to give them a group/practice test about a week prior, to give them a chance to study together before the "real" test a week later. (When I call it a "review," they treat it as a homework and just don't take it seriously!) They work in cooperative groups of 3 or 4, and since my students change groups every 3 weeks, I choose who their groups will be.
I weight it one-quarter the weight of a "real" test in the gradebook. I give students the option of working alone if they feel their group won't be productive, although students rarely take me up on that offer. (On rare occasions, a "drone" will do very little; in this case, I separate their group test from the rest, grade it separately, and treat the remaining papers as a separate group.)
When they turn it in, they staple all 3 or 4 group members' tests together, and then I grade problem 1 of the first test, problem 2 of the second test, problem 3 of the third test, and so on. Then I add up the points, and all students receive the same score.
Since I'm only assessing 1 out of every 3 or 4 problems, it goes very quickly, and I can give them feedback easily by the next class. They then have about a week to prepare and/or use it as a study guide to get them ready for the test the next week.
Please download the pdf preview file first, so you can see exactly what's included; the product file is a word document, which you may personalize for your students.
NOTE: Students take longer to complete a group test than a comparable individual test. Because I have 90-minute blocks at my school, I expect them to finish this test within one block. If you have shorter periods, I would recommend having the entire class dedicated to completing this test. I never recommend that you have them work on it over two class periods, as the very small number of absent students (some of whom will be absent the first day, and others the second day) will gum up the concept of a shared group practice test.