Researchers have spent decades investigating the most valid predictors and measures of teacher quality, with one of the hopes being that school districts will know exactly what to look for when hiring new teachers.

A team of German researchers have contributed a new study to the catalogue of teacher quality data and analysis, investigating what might be good predictors of an effective teacher, looking at personality traits of teachers and how well they did in high school, their teacher prep program, and student teaching.

The findings are interesting, but not groundbreaking. Providing more evidence on the importance of student teaching, a student teacher's performance was the most predictive factor of later effectiveness. More interesting, though, was the fact that high school GPA was also a predictor of how effective a teacher would be, only because it predicted how well someone would do in their student teaching.

Teachers who scored high on any of the Big Five personality traits (extraversion, agreeableness, openness, conscientiousness, and neuroticism) were no more likely to be effective, at least in terms of adding to student academics. However, a teacher's high score on "agreeableness" did predict that she would be more effective in providing social support to her students.

With state assessments canceled because of the pandemic and districts unsure how to evaluate their teachers for the 2019-2020 school year, it is important to note that the researchers relied on student survey data rather than test scores to measure teacher quality. More than half of all states now either require or permit the use of student surveys in teacher evaluations, though it is less clear if many districts are using this tool. Previous research has found that student surveys align both with observation ratings and student test scores.