We implemented a TSO policy in 2008. Students could choose to not report their SAT and ACT scores to us. A number of unexpected things happened. First, not as many applicants chose TSO as many had predicted. Second, the people you would expect to choose TSO did not always do so, while some chose it and you wonder why they did. Also, the difference between our TSO average and the averages for all tests did not differ much. (A number of students chose to send scores and later chose TSO.)
The following histogram (using FA11 depositor data from June 1) illustrates my observations. The vertical distance between the red and black horizontal bars at a given ACT score shows the number who chose TSO under the ACT test. (SAT results show a similar pattern.)
(Click on the graph to enlarge it.)
You might surmise that the averages did not change much as a result of TSO, and that would be correct. The TSO average was 25.7 vs. 24.9 for the average of all scores we could get. (Similarly, for the SAT, the averages were 1137 vs. 1119.)
83 depositors chose to drop their scores and another 82 never reported them to us in the first place, out of a group of 597 June 1, 2011 depositors.