One of the most important medical discoveries of the 20th century was also one of the simplest. In 1968, two American researchers published a study of a new treatment for cholera, a virulent disease that commonly killed 70 percent of its victims. The researchers found that a mixture of sugar, salt, and water, taken orally, could rehydrate cholera patients and reduce mortality rates by more than 90 percent (Gawande, 2013).
One would expect that such a simple life-saving technique, involving ingredients that could be found in most kitchens, would spread rapidly. Just get out the word and watch the practice take hold, right?
Sadly, that wasn't the case. More than a decade after scientists announced the breakthrough to the world, nurses and caregivers in developing nations where the disease was most prevalent were either ignoring the new rehydration methods or performing them incorrectly. As a result, cholera and other diarrheal diseases continued to claim millions of lives.
A similar phenomenon seems to have been occurring in education for many decades, ever since we learned about a simple and straightforward teaching technique—one that can dramatically improve student learning yet remains far from common practice.
A Simple Idea Supported by Research
In the 1960s, education researcher Benjamin Bloom advanced a simple idea: to apply the key elements of one-on-one tutoring, shown to be the most effective teaching technique we know, to whole-class settings. The approach was called mastery learning. Over the years, different interpretations, nuances, and names have been applied to describe mastery learning practices, but essentially, the approach weaves together the following elements (Guskey, 2007; Hunter, 1985):
- Set clear learning objectives.
- Use an anticipatory set to focus and engage students in their learning.
- Present information and model new knowledge or skills.
- Provide students with opportunities for deliberate practice.
- Use regular formative assessments to check for student understanding.
- Reteach as needed, using individualized interventions targeted to learning needs.
- Confirm understanding before moving on to new content.
As with most teaching practices, the research supporting mastery learning isn't unanimous (Slavin, 1989), but over the years, a compelling case has been made for mastery learning. An early study of mastery methods found that they were able to help three-quarters of students learn at the same levels as the top one-quarter of students in the control group (Block, 1971). A meta-analysis of 108 studies of mastery learning found that students in mastery learning settings achieved an average of 20 percentile points higher than students in non-mastery settings—at the 70th percentile versus the 50th percentile (Kulik, Kulik, Bangert-Drowns, & Slavin, 1990).
Mastery learning may also resolve the enduring dilemma of how to focus additional support on struggling students while still challenging high performers. As commonly conceived, mastery learning engages high achievers in enrichment activities while struggling students receive remedial support (English, Dickinson, McBride, Milligan, & Nichols, 2004). In their 1990 meta-analysis of mastery learning studies, Kulik and colleagues found positive effects for high-achieving students, but even greater effects for low-achieving students, prompting the researchers to conclude that "mastery programs … may smooth out the differences between high and low aptitude learners" (p. 286).
Why Hasn't Mastery Learning Spread?
Despite the prevalence of data supporting mastery learning, the practice appears to be far from commonplace in classrooms. If we have so much evidence to support mastery learning, why don't we use it more?
One reason appears to be that although the idea is simple and straightforward, it's far from easy to implement (English et al., 2004). For starters, there are technical challenges, such as the need to develop or adopt a robust battery of formative assessments and then to develop remedial interventions linked to these formative assessments (Guskey, 2007).
The concept of mastery learning is also susceptible to misinterpretation. Over the years, some have rejected it because they see it as a lock-step approach to teaching. Hunter (1985), however, argued that mastery teaching should be seen as a "launching pad from which creativity can soar" (p. 58). For example, both direct instruction and inquiry-based learning can fit within the model.
Finally, mastery learning may require teachers to adopt new approaches to instruction. For example, they may need to rethink grading practices to provide students with opportunities to be reassessed and regraded (English et al., 2004). These fundamental changes in teaching practices, along with the technical challenges of implementation, mean that intensive professional development (including observation, feedback, and coaching) is required to help teachers correctly apply the approach in their classrooms (Hunter, 1985).
All of this complexity suggests that mastery learning, although simple to propose, is not necessarily easy to implement. That's why the solution to encouraging the spread of mastery learning may not be so different from the solution that health officials eventually developed to encourage the use of sugar-saline rehydration for cholera patients.
Getting the Word Out—Door to Door
Health officials in Bangladesh found that the most important impediments to adoption of the new medical treatment for cholera were the attitudes and understandings of local health providers and caregivers. Simply pushing out information through a top-down media campaign using radio, TV, and print brochures did little to change practices.
Eventually, the health officials hit upon a different, albeit more old-fashioned, approach to spreading the word: They hired counselors to go village by village, door to door, sitting down with caregivers to explain how the new treatment could save lives, to answer questions, and most important, to teach the caregivers how to mix the solution and give it to patients. As a result, the new practice spread widely and child deaths from diarrhea in Bangladesh fell more than 80 percent between 1980 and 2005 (Gawande, 2013).
Similarly, getting mastery teaching approaches to take hold may require collaboration and coaching as well as systemwide support. Given the preponderance of evidence supporting mastery learning, it might be tempting to think that we simply need to push the right information out to educators—and if that doesn't work, perhaps we need to apply external pressure. However, with a conceptually simple yet procedurally complex practice like mastery learning, top-down information and pressure do little to change practice. Indeed, as Michael Fullan (2011) asserts, external pressure may be precisely the wrong driver to improve instructional practices.
A better approach may resemble the door-to-door, village-by-village approach of health care workers in Bangladesh. And because of the increasing prevalence of teacher coaches today, such an approach may be more possible than it has been in the past. As noted in a previous column (Goodwin, 2013), however, coaches are only as effective as the models of instruction on which they coach teachers. Mastery learning appears to be a good place to begin.
