An earlier study from the Houston Education Research Consortium showed teachers in the Houston Independent School District's highest-need schools received lower value-added scores on average than teachers in the district's lower-need schools. It was unclear whether this was an indication that HISD's highest-need schools staffed lower quality teachers or whether teachers at the highest-need schools were being penalized because of issues within the value-added methodology.

Using longitudinal data, this report looks at teachers between 2007-2008 and 2012-2013, as well as their students and schools, to investigate the degree to which value-added scores capture the impact of teachers on student achievement gains rather than the influence of factors beyond the teachers' control.