J B Carroll's Philosophy of Education in comparison to Mastery Learning

KEY REFERENCE: Carroll, J.B., (1989) “The Carroll Model. A 25-year retrospective and prospective study view”. Educational Researcher 18(1) 26-31.

For a quick overview of this topic read everything in BOLD type in the wiki. For a more thorough view read EVERYTHING evil

The American PsycholJ B Carrollogist JB Carroll’s model on learning within a school setting directly influenced Bloom, who originally coined the term “Mastery Learning”. However, Carroll referred to his model as being a broad theoretical basis for learning, and did not adopt or necessarily endorse the term “Mastery Learning”.

The most useful paper that Carroll produced that refers to both his original model and work built upon its foundations is given as the key reference for this topic. It explains clearly Carroll’s thoughts on adaptations of his original theory, as well as a good summary of his model of school learning and his thoughts on mastery learning.

The remainder of this page will be split in to three sections. The first will provide a brief summary of Carroll’s model of school learning. This will then be followed by his own philosophy of education, which will be contrasted to Bloom’s “Mastery Learning”. Finally experimental evidence for JBCarroll’s model will be provided

A Brief Summary of “A Model of School Learning”

JB Carroll (1963) suggested that five variables affected learning within a classroom setting.

Aptitude – The amount of time a student needs to learn
Opportunity to Learn – The amount of time allowed for learning
Perseverance – The amount of time a student is willing to put in to learning
Quality of Instruction – The quality of the teaching method/methods used.
Ability to Understand Instruction – The student being able to understand what is being taught

Carroll's Model of School Learning

Therefore, an individual's ability to learn is dependent on their aptitude - the time they need to learn, and whether or not the instruction they are given meets this time requirement. The quality of instruction and and the students willingness to learn act as moderating factors. For instance, less instruction is needed if the quality of instruction is high. If the student on the other hand is highly motivated but the quality of instruction is low, they can nevertheless achieve well academically.

Carroll’s Philosophy of Education in contrast to Mastery Learning

Mastery Learning, a concept first introduced by Benjamin Bloom was based to some extent on Carroll's Model of School learning.

Essentially, mastery learning follows the assumption that all children can master a given topic so long as they have enough time to do so. Thus, normal distributions of exams scores are seen as misleading because they are merely an example of how well individuals can do under rigid time constraints. According to mastery learning, with enough time all individuals can do well and "master" a given subject or task. Bloom suggested that up to 90% of students can achieve mastery if given the opportunity, and that the current education system (at the time of his writing in late 1960s America) was in fact detrimental to learning. He suggested this was due to teacher's assumptions that around 30% of pupils could master a given subject, and that the remaining 70% of a class could not. In turn, this created a self-fulfilling prophecy wherby pupils assumed to be able to master a subject did, and the remaining 70% did not.

While Bloom explicity used Carroll's work as a basis to mastery learning, as mentioned above Carroll neither endorsed Mastery Learning or agreed with it's philosophical underpinnings. To Carroll, mastery learning was neither attainable nor neccessarily desirable for all learners. Carroll instead focused not on equality of attainment but equality and diversity of opportunity by way of tailored instruction and learning specific to aptitude. Carroll suggested that the potential of learners should be regularily assessed, and that instruction should be appropriate to this potential. Instead of aiming for an all round concept of mastery, learners should aspire to master a subject as far as their aptitude allows them and that this should also be the aim of teachers.

Essentially, and from my own understanding Carroll and Bloom differ in their focus on individual differences and whether or not these are maleable or concrete characteristics, and how much they contribute to and affect learning. To Bloom, individuals only differ in the time they need to learn. In contrast Carroll postulates that individual differences affect how effectively an individual can master a subject.

Experimental Findings in relation to “A Model of School Learning”

It seems common sense to think that increasing the amount of time an individual has available to learn increases their achievement but Carroll was very much credited with this assertion. Several studies support this idea.

Bellei (2009) found in Chilean schools that academic achievement improved when the school day was increased dramatically. Supports Opportunity to Learn as an important variable.

Cooper et al (1998) found that the amount of homework or time expected to be spent on homework did not increase achievement. Instead, they found the amount of time children put in to doing homework affected acheivement. Supports Perseverance as an important variable, especially in terms of non-school day learning.

In terms of Carroll's other three variables; aptitude, ability to understand intructions and quality of instructions their is a wealth of experimental evidence supporting their importance. However, exactly how one measures and judges an individuals aptitude, quality of instruction and how well an individual understand instruction is very much debatable. Their is also a large amount of argument about how to improve learning through these variables. It also seems clear their is a gap in the literature between theoretical assertions and assumptions and real world effects and applications that needs to be addressed.


Bellei, C. (2009) Does lengthening the school day increase students’ academic achievement? Results from a natural experiment in Chile. Economics of Education Review 28(5); 629-640.

Bloom, B. (1968) Learning for Mastery. Evaluation Comment 1(2); 72-89.

Carroll, J.B. (1963) A Model of School Learning. Teachers College Records 64; 723-733.

Carroll, J.B., (1989) “The Carroll Model. A 25-year retrospective and prospective study view”. Educational Researcher 18(1), 26-31.

Cooper, H., Lindsay, J.J., Nye, B. and Greathouse, S. (1998) Relationships among attitudes about homework, amount of homework assigned and completed, and student achievement. Journal of Educational Psychology 90(1); 70-83.