The need for differentiated instruction is acknowledged in theory, but neglected in practice. Students begin a course with different knowledge, abilities, and interests. In spite of their diversity, they usually receive uniform instruction. Clearly, students would benefit if their unique learning needs were met, so why don't most teachers provide differentiated instruction?
Simply put, teachers face constraints, and as usually depicted, differentiated instruction would be impractical, even burdensome, to implement. Teachers are justifiably wary of differentiated instruction because it represents a logistical nightmare. It is difficult enough for a teacher to plan and manage instructional activities for a few classes of students, let alone multiple subgroups within each class. Teachers need a workable model, not disconnected suggestions or a manifesto that amounts to little more than a wish list.
Mastery models represent sensible solutions to a daunting problem, implementation of differentiated instruction. Mastery models promote a simple, systematic approach to assessment, and they do not prescribe or favor any particular instructional philosophy (e.g. direct instruction, guided discovery, etc.).
Do mastery models require more work on the parts of both teachers and students? Yes. However, the increase in work is well within reason, and the payoff is impressive, to say the least.
|Model||Type of Instruction||% of Students Attaining Mastery|
Learning for Mastery and Personalized System of Instruction
Please select a section to learn about two mastery models, their effectiveness, and how mastery principles relate to recommendations from the Institute of Education Sciences.
As Guskey chronicles in Implementing Mastery Learning (1996), Benjamin Bloom and Fred Keller independently developed mastery models during the 1960s. Bloom dubbed his model Learning for Mastery (LFM), and Keller dubbed his model the Personalized System of Instruction(PSI). Today, Bloom's Learning for Mastery is usually referred to as Bloom's Mastery Learning.
The two models share the following essential features:
- Alignment of objectives, instruction, and assessments
- Formative assessments with a mastery standard
- Strong emphasis on remediation
But the models also differ in significant ways. See the table below for a quick comparison. Historically, K-12 teachers have overwhelmingly implemented Bloom's LFM, and college teachers have usually implemented Keller's PSI. Teacher needs, student needs, and practical constraints influence decisions about which mastery model to implement.
|Mastery Model||Pace Setter||Social Context||Remediation||Enrichment|
|Learning for Mastery||Teacher||Group||Strong||Strong|
|Personalized System of Instruction||Student||Individual||Strong||Weak|
The models are described in more detail below. Click on a model to reveal a summary and diagram. Click again to hide the summary and diagram.
Learning for Mastery
Bloom's Learning for Mastery (LFM) calls for teacher-paced, group instruction. Students move through the course as a group, and during each unit they receive the same instruction through the first assessment. Following the first assessment, students who meet the mastery standard receive enrichment while students who score below the mastery standard receive remediation.
Due to time constraints, LFM teachers generally only offer one opportunity to retake, revise, or redo an assessment. Quizzes are retaken; projects are revised; and performances are redone. (For quizzes in particular, parallel assessments should be used, not identical assessments.) Some teachers count the higher of the two scores while other teachers always count the score from the second assessment. For enrichment students, the second assessment may be optional.
Personalized System of Instruction
Keller's Personalized System of Instruction (PSI) calls for self-paced, individualized instruction. It requires students to demonstrate mastery before moving on to the next unit, which in turn necessitates multiple opportunities to retake or revise an assessment. Hypothetically, students who always meet the mastery standard could complete a PSI course much more quickly than students who often score below the mastery standard and require remediation.
PSI teachers also face practical constraints, and they often decide to cap the number of assessment attempts. PSI teachers should construct parallel assessments in the same manner as LFM teachers.
Since the late 1960s, researchers have performed dozens of studies on Bloom's Learning for Mastery (LFM) and Keller's Personalized System of Instruction (PSI), and several researchers have performed a meta-analysis of the studies in an attempt to summarize the available data. In 1990 Kulik, Kulik, and Bangert-Drowns reported the results of their meta-analysis, the most exhaustive ever conducted. Their goals were to gauge the effectiveness of mastery learning and identify the factors that impact its effectiveness.
After noting that mastery learning is not only effective, but also efficient (students in a mastery class typically spend just 2-3 minutes more per hour on their work), Kulik et al. concluded their analysis with the following remarks:
We recently reviewed meta-analyses in nearly 40 different areas of educational research. Few educational treatments of any sort were consistently associated with achievement effects as large as those produced by mastery teaching (p. 292).
The mastery model predicts higher examination scores, reduced variation in examination scores, and more positive academic attitudes with mastery teaching, and we found all of these effects in mastery classes. The effects, however, were not as large as sometimes claimed for mastery procedures (p. 292).
Kulik et al. found that a few factors were associated with strong achievement effects on local tests and moderate achievement effects on standardized tests. The factors included:
Mastery programs that lacked these characteristics generally produced weak achievement effects on standardized tests.
The meta-analysis is described in more detail below. Click on a section of the study to reveal a summary. Click again to hide the summary.
After scouring the available literature and compiling studies, Kulik et al. evaluated each study. To be included in the meta-analysis, a study had to meet the following criteria:
- Controlled experiment
- Good methodology
- Mastery standard (70% or higher)
- Quantitative results
The researchers selected 108 studies for analysis. One third of the studies involved Bloom's LFM, and two-thirds involved Keller's PSI. College students were the subjects in 91 studies. K-12 students were the subjects in 17 studies, all focused on Bloom's LFM.
To facilitate comparison of student achievement across studies, Kulik et al. retrieved student test means from every study and calculated the effect size. Whenever possible, the researchers retrieved both pre-test and post-test means to estimate growth. Post-test means from end-of-instruction assessments (local tests, standardized tests, or both) were obtained from 103 studies. Five PSI studies did not report post-test means.
Kulik et al. calculated mean effect sizes of 0.59 and 0.49 for Bloom's LFM and Keller's PSI, respectively. And they calculated a combined mean effect size of 0.52, or an average increase of 0.52 standard deviations. The typical mastery student scored at the 70th percentile on the end-of-instruction assessment whereas the typical traditional student scored at the 50th percentile. This is an achievement effect of moderate strength.
Although Keller's PSI had a small negative effect on course completion, Kulik et al. found no connection between course completion and student achievement. The researchers asserted, "Higher student achievement in PSI classes is not an illusion created by the withdrawal of the weaker students before final-examination time" (p. 286).
To view a table that will help you interpret the effect sizes, click the button below.
IES Practice Guide
In 2007 the Institute of Education Sciences (IES), the US Department of Education's research center, published a practice guide by Pashler et al. entitled Organizing Instruction and Study to Improve Student Learning. The purpose of an IES practice guide is to offer concrete recommendations that are feasible, evidence-based, and coherent.
The practice guide makes seven recommendations. More than half of the recommendations relate to mastery learning, and a couple recommendations are straight out of the mastery learning playbook:
|Recommendation||Level of Evidence||Related Mastery Learning Practice(s)|
|1. Space learning over time.||Moderate||N/A|
|2. Interleave worked example solutions with problem-solving exercises.||Moderate||Both: Following Assessment A, teachers provide worked examples (e.g. demonstrations and/or answer keys with worked answers). Remedial students perform targeted activities prior to Assessment B.|
|3. Combine graphics with verbal descriptions.||Moderate||N/A|
|4. Connect and integrate abstract and concrete representations of concepts.||Moderate||N/A|
|5a. Quizzing: Use pre-questions to introduce a new topic.||Low||N/A|
|5b. Quizzing: Use quizzes to re-expose students to key content.||Strong||Both: Teachers offer students who score below the mastery level on Quiz A an opportunity to take Quiz B, a parallel quiz.
Bloom's LFM: Teachers are encouraged to select a few important questions from past units' quizzes and place them on the current unit's quizzes.
|6a. Self-Management: Teach students how to use delayed judgments of learning to identify content that needs further study.||Low||N/A|
|6b. Self-Management: Use tests and quizzes to identify content that needs to be learned.||Low||Both: Both teachers and students use Quiz A to diagnose student learning needs. Students then perform targeted remedial activities in preparation for Quiz B.
Bloom's LFM: Teachers reteach difficult concepts, procedures, processes, etc.
|7. Ask deep explanatory questions.||Strong||Both: Teachers align objectives, instruction, and assessment.
Bloom's LFM: When designing each unit, teachers are encouraged to use Bloom's Taxonomy, which promotes high-level objectives.