Learning progress monitoring (LPM) is an effective tool for teachers to improve students’ performance by systematically and quickly responding to achievement data. However, studies show that in-service and preservice teachers often have difficulties using LPM because of lacking graph literacy, especially with high data ambiguity. The present study examines whether (a) preservice teachers are biased by gender stereotypes when predicting students’ performance based on progress data, (b) the preservice teachers’ gender affected their predictions differentially depending on student gender, and (c) the insertion of a trend line or lowered data variability diminishes the gender bias in predictions. N = 134 preservice teachers received 16 experimental student vignettes online via the internet in random order which depicted the learning progress of boys and girls in oral reading fluency assessment over a period of 11 weeks. Half of the participants were presented with progress data accompanied by a trend line, the other half received progress data only. Results evidenced that preservice teachers were prone to a gender bias favoring girls. The gender bias was attenuated when a trend line was presented or when data variability was low, with male participants benefitting more from the trend line, and female participants benefitting more from low data variability. The adaptation of international training programs to enhance graph literacy and to diminish gender stereotyping in German teachers is recommendable.

Keywords
learning progress monitoring (LPM), graph literacy, oral reading fluency, data ambiguity, gender bias, stereotypes