COVID-stressed schools struggled to teach mathematics

The COVID-19 pandemic led to temporary closures of schools in Germany that were unpredictable, either short-term or sustained over many weeks depending on local COVID-19 incidence rates which varied in different regions over time. The COVID-19 pandemic created new stressors in schools to deliver the curriculum with reduced lessons and online teaching. COVID-19 also had a marked effect on research in schools.

The INSIDE project is a nationwide German study that investigates the effects of inclusive schooling in secondary education. The data collection started in 2018 and is still ongoing. During the COVID-19 pandemic the drop-out of many schools lead to a sample attrition down to 39.3 % of the original sample. It is investigated whether imputation of missing values in the dependent variables school grades (N = 2999) produces different results than listwise deletion of cases (N = 383).

It is hypothesized that missing data in the longitudinal data design were not missing at random (NMAR). It is further hypothesized based on previous research that in the larger, imputed sample, Math grades will deteriorate more than German grades.

Two datasets with observed, respectively, imputed data showed no difference in parents' educational attainment and gender proportion. Larger integrative schools were less likely to drop out than smaller single type schools. Pupils of 'surviving' schools showed equivalent grades for German and Mathematics, while including predicted grades of pupils in 'stressed' drop-out schools showed a decline in Mathematics but not in German subject grades.