Related to the first theory of «high expectations,» we
find students assigned to a teacher who shares their race and gender are more likely to say their teacher pushes them to work hard, requires them to explain their answers, not to give up when the work gets hard, and accepts nothing less than their full effort.
Not surprisingly, teachers who are successful with students in one year tend to be successful in other years; hence, measures of a teacher's performance in the past tend to be a good predictor of how well
future students assigned to that teacher will achieve.
My research design effectively compared the performance
of students assigned to teachers of the same race with the performance of students who were assigned to teachers of a different race but who were in the same grade and who entered the experiment in the same school and year.
Chetty and his colleagues show, using quasi-experimental tests, that «standard VA measures are not biased by
the students assigned to each teacher.»
A student assigned to a teacher with a VA 1 standard deviation higher is 0.5 percentage points more likely to attend college at age 20 (an increase of 1.3 percent).
We show directly using quasi-experimental tests that standard VA measures are not biased by
the students assigned to each teacher.
That is, if we take two students who have the same 4th - grade test scores, demographics, classroom characteristics, and so forth,
the student assigned to a teacher with higher VA in grade 5 does not systematically have different parental income or other characteristics.
There are many sources of random error in value - added estimates: standardized tests have measurement error, some students are sick at test - taking time, and
the students assigned to teachers in any given year vary in essentially random ways.
: Lists all the students in a teacher's class (designed for verifying
the students assigned to each teacher for screening and progress monitoring).
According to the testimony of Harvard economist Dr. Thomas Kane, a student assigned to the classroom of a grossly ineffective math teacher in Los Angeles loses almost an entire year of learning compared to
a student assigned to a teacher of even average effectiveness.