Here are the results for the first year of the “Capital Gains” experiment in terms of math scores. First, the tables:
The table above is for the control group of schools. The cells that I highlighted in read show that overall, there was a small decline (from 42.9% to 42.1%, or a change of -0.8%) in the percentage of students scoring “proficient” or better on the DC-CAS from spring 2008 to spring 2009 in the control group of schools – the 15 schools where the students were not given payments for being good.
Next, let’s see the results for the experimental group:
I hope that you can see that there was a slight increase (from 34.7% to 37.1%, or +2.5%) in the percentage of students scoring proficient or above on the DC-CAS from Spring 2008 to Spring 2009 in the experimental group of schools – that is, the ones where the students DID receive payments for coming to school on time, doing homework, having good behavior, and so on.
The control group started off with a significantly higher proportion of students scoring “proficient” or better in math: 42.1% in 2008 as opposed to 34.7% for the experimental group. This tends to make me think that the entire experiment was not set up very well, since I have already shown that the two groups had quite different demographics.
Bottom line(s)?
- The control group started out and finished with higher scores in both reading and math; the two groups had major demographic differences as well — all signs of a poorly-planned experiment.
- The control group went up by 0.6% in reading; the experimental group went down by 1.9%. (Not big changes in either case, in my opinion).
- The control group went down by 0.8% in math; the experimental group went up by 2.5%. (Almost the mirror image of what happened in reading).
- My opinion? Not a significant result either way.
I have so far received no response for my requests for information from Roland Fryer, the Harvard professor who apparently dreamed up this idea. Today, I found a couple of other numbers for him on Switchboard.com, but they didn’t work, either.
Here is my latest email to him:
======================================
Hello, Dr. Fryer,
This is my second request via email for clarification on the “Capital Gains” experiment that you initiated here in Washington, DC.
I have also left phone messages with your support staff-person, xxxx xxxxxxxx, as well as with another staffer in the Harvard Economics department.
My numerous attempts over the past two weeks to call you directly, or even to leave a message on your office phone line have all failed because your voice mailbox remains full.
My request from you is rather simple, and two-fold:
(1) Since there are various different accounts in the public record of how many schools are in the experimental and control groups in this experiment, can you please share with me the current and correct names of the schools?
(2) Are there any publicly-available sources of data on attendance or anything else for these two lists of schools that you are using as measurement outcomes?
You can either reply to me via this email, or you can call me directly at xxx-xxx-xxxx.
Thanking you in advance for your cooperation, I am,
Sincerely,
Guy Brandenburg, Washington, DC
My blog, mostly on Education in DC:
https://gfbrandenburg.wordpress.com/
=====================================
Leave a Reply