Students differ in mastery of the skills and knowledge prerequisites for successful
learning in that classroom.
Students differ in the time needed for learning a given unit of material or to attain a
particular educational objective. The slowest 10 percent of students need 2.4 to 6 times
as much time as the highest 10 percent.
Students differ in race, sex, socioeconomic level of parents and age.
Students differ in self-concept, interest in school, motivation to learn and personal
education goals.
Accomodating such student heterogeneity is one of the most troublesome and enduring
problems faced by teachers.
Both high and low ability students do better academically in classes where the total group
includes students with a wide range of academic ability. The impact is greater on low ability
students. There is no difference in average ability students' academic performance in classes
that are academically heterogenoous or homogeneous.
Short-term lesson-by-lesson instructional groups provide review, practice and enrichment
opportunities that effectively meet the diverse learning needs of students in a heterogeneous
classroom.
Although instructional grouping is used to reduce the range of differences in the students
being taught at a given point in time, the abilities of students in the various groups, even
long-term ability groups, overlap considerably.
Most studies of small group versus whole class instruction find greater learning on the part
of students when the teacher uses small instructional groups for at least part of the time.
High and low ability students benefit more than average students.
Achievement gains are less clear in mathematics than reading. In math, students in
peer tutoring groups show more significant gains in math computation than in math
concepts and applications. Students who complete group investigation tasks acquire
more high level math skills than those engaged in total class instruction.
Cooperative group experiences increase girls' achievement more than boys'.
Student achievement in instructional groups is related to the teacher's ability to solve
classroom management problems associated with the use of small groups.
An exception to student achievement gains occurs in long-term ability groups.
Positive achievement effects are found only for high ability students, and these results
occur only in some studies.
No effects occur for moderate ability students beyond the learning that occurs when
these students are taught in a total classroom setting.
Harmful effects are identified for low ability students. Pull-out low ability groups have
a particularly adverse impact upon the performance of low ability students.
In desegregated classrooms, cooperative learning groups produce significant gains in
academic achievement for minority group students.
In cooperative groups, students who help others by providing explanations or demonstrations
of how to complete assigned tasks gain more in achievement than students at the same ability
level who are recipients of help.
Group investigations, particularly ones that do not include competition between teams,
promote use of abstract thinking, problem solving, and critical thinking skills.
Students change over time. This should lead to changes in their instructional grouping.
When ability groups are used, exit criteria should be specified so it is clear when a
student should be moved to another group.
When teachers do not give specific attention to accommodating changes in students
and have no criteria for exiting an ability group, student assignments to ability groups
remain stable. At most, six percent of the students in a classroom will be moved from