Numerous studies have shown that high teacher expectations are positively associated with better student academic and sociopsychological outcomes.  A longitudinal study was published in Learning and Individual Differences, in which Wang and colleagues examined the stability and trajectories of teacher expectations within a school year in the Chinese junior high school context.  

The study involved 48 teachers and their 1199 seventh grade students from 32 classrooms in 10 schools in northern China. Students’ achievement scores in Chinese, Mathematics, and English were collected four times in a school year. Teachers rated their expectations of their students’ results in the final examination three times across the school year. In the study, teacher expectations were conceptualized as the discrepancies between teacher expectation scores and student achievement, therefore, teacher expectations represented the expectation bias that teachers held for their students.  The results indicated that: 

• Students in the high-achieving group were systematically overestimated, and the extent of overestimation increased over a school year for both Chinese and Mathematics subjects.
• Students in the high-achieving group were overestimated at the first two time points but alleviated at the third one for the English subject.
• Students in the low-achieving group were systematically underestimated across the school year. 
• Teacher expectations for their medium-achieving group were comparably more accurate and relatively stable across the school year.

The results suggested that teachers might enlarge the existing achievement differences between students by expecting more from the high achievers and expecting unjustifiably less from the low achievers. The authors suggested that teachers should be more aware of their expectations, especially their expectations shown towards low achieving-students. 

Source: Wang, S., Rubie-Davies, C. M., & Meissel, K. (2020). The stability and trajectories of teacher expectations: Student achievement level as a moderator. Learning and Individual Differences, 78, 101819. https://doi.org/10.1016/j.lindif.2019.101819