A proposed model of the effects of ease of grading in science on enrollments is tested with data gathered in 27 high schools. Grades were transcribed for students in the 1968 graduating class; they were coded A = 7, B+ = 6, B = 5, …, F = 0.

East of grading was calculated for each science teacher and course in each school. In addition the proportion of non-senior students who moved from one science to the next in the typical sequence was determined.

Analyses of variance indicated that teachers were the major distinguishable source of variance in ease of grading. Analysis of teachers' ease of grading indicated that female students were graded more severely than male students, and grading in the physical sciences was more severe than grading in biology.

Analyses of the effects of ease of grading on students' transitions from course to course indicated that experienced ease or severity of grading was more important for female students than for male students, while anticipated ease or severity of grading was important for all transitions, except that of male students into physics.

These results are taken as evidence supporting the first three propositions of the model, though it appears that some modification to account for sex differences will be appropriate. Estimates from the data suggest that an increase in science enrollments of practical significance would follow an effort to bring science grades to “par” with other academic grades. Finally it is noted that efforts to achieve effective general education in the sciences through attention to grading practices alone will probably be inadequate.