Scaffolded, Tailored Algebra Teaching Lifts Student Scores in Ghanaian Trial

A three-week classroom experiment in Ghana has added fresh weight to an idea many teachers instinctively believe but few have tested so directly: that algebra lessons work dramatically better when instruction is tailored to each student’s readiness level and supported by carefully staged, gradually withdrawn help. In a quasi-experimental study published in Frontiers in Education, researchers from the University of Skills Training and Entrepreneurial Development in Kumasi found that students taught with scaffolding-based differentiated instruction gained roughly three times as much on an algebra achievement test as peers taught by the conventional lecture method. The findings arrive at a moment when mathematics classrooms worldwide are becoming more diverse, and when the gap between what students can mechanically execute and what they genuinely understand has become one of the most stubborn problems in education.

The research team, led by John Ackon with colleagues Francis Ohene Boateng and Benjamin Adu Obeng, worked with 120 Form Two students at Asanteman Senior High School, a population of roughly 800 students at the stage where algebra becomes a gateway to science, engineering, technology and economics. Two intact classes of 60 students each were compared. One class received the experimental treatment; the other continued with the lecture method that still predominates in many Ghanaian senior high schools. Both groups covered the same algebra topics, including algebraic expressions, linear equations and contextualised problem-solving, and both received equal instructional time from the same teacher, a design choice intended to isolate the instructional strategy as the only meaningful difference between conditions.

The mechanics of the intervention are worth examining because they illustrate what differentiated instruction actually looks like when it moves from theory to practice. Before lessons began, students’ readiness levels were diagnosed using a pretest. Those with weaker foundations received additional teacher guidance, worked examples, step-by-step explanations and guided practice, while stronger students were given more challenging tasks designed to stretch independent reasoning. Each lesson followed a structured scaffolding arc: explicit explanation and modelling first, then guided practice with questioning, peer collaboration and differentiated tasks, then a deliberate fading of support. As students demonstrated growing competence and confidence, the teacher reduced prompts, increased independent practice and allowed learners to tackle progressively harder problems with less assistance.

This fading is the conceptual heart of scaffolding. Drawing on Vygotskian ideas, the approach targets what psychologists call the Zone of Proximal Development, the space between what a learner can do alone and what they can do with help. Support is temporary by design; the goal is not dependence on the teacher but a progressive transfer of responsibility to the student. The researchers also drew on Multiple Intelligences Theory, which holds that learners possess varied intellectual strengths and therefore benefit from varied instructional pathways, a framework that remains debated among psychologists but has proven practically useful for justifying differentiated classrooms.

The outcome measure was a researcher-developed Mathematics Achievement Test of ten application-based algebra questions, designed to capture both mathematical understanding, meaning the interpretation of expressions and identification of relationships, and problem-solving performance, meaning the application of strategies and procedures to algebraic situations. The instrument was vetted by experts in mathematics education and measurement, pilot-tested with 115 comparable students, and showed acceptable psychometric credentials: an average item difficulty of 0.59, an average discrimination index of 0.43, and internal consistency of 0.79 on the Kuder-Richardson Formula 20. Student perceptions were measured with a ten-item questionnaire on a five-point scale, which achieved a Cronbach’s alpha of 0.764.

The results were striking. Before the intervention, the two groups were statistically indistinguishable, with mean pretest scores of 61 for the experimental group and 60 for the control group. After three weeks, the lecture group had improved modestly from 60 to 65, a five-point gain. The scaffolding-based differentiated instruction group climbed from 61 to 75, a fourteen-point gain. Because the researchers used Analysis of Covariance with pretest scores as a covariate, they could statistically adjust for any initial differences, and the adjusted comparison was emphatic: instructional approach had a significant effect on posttest performance, F(1,117) = 278.511, p < .001, with a partial eta squared of 0.704, an unusually large effect size for a classroom intervention. The overall model explained 74.1 percent of the variance in posttest scores. Students taught by lecture scored, on average, 8.90 points lower than their scaffolded peers after adjustment, with a 95 percent confidence interval of 6.35 to 11.45 points.

Perhaps more telling than the raw means was the movement of students across proficiency categories. The researchers classified students as Approaching Proficiency, Proficient or Highly Proficient based on percentage scores. Before the intervention, most students in both groups sat in the lowest category, with 24 students in the experimental group and 23 in the control group below the 60 percent threshold. Afterward, the lecture group’s lowest band shrank only slightly, from 23 to 18 students. In the experimental group, it collapsed from 24 to just 5. Meanwhile, the number of Highly Proficient students in the scaffolded class more than doubled, from 13 to 29, while the control group managed only 13 to 15. This pattern suggests the approach did not merely lift the middle; it pulled struggling students across a meaningful threshold and pushed capable students toward genuine mastery, exactly the dual effect differentiated instruction is designed to achieve.

Students noticed the difference. The perception questionnaire, administered only to the experimental group, yielded an overall mean of 3.423 with a standard deviation of 0.588, indicating moderately positive views. The highest-rated items, each scoring 3.54, were that step-by-step support helped students understand better and that they preferred the method to the usual lecture approach. Students also rated hints and guidance for difficult questions, peer collaboration, and growing independence in problem-solving favourably. The lowest-rated item, at 3.28, was the statement that support was gradually reduced as students improved, still above the scale midpoint but hinting that the fading of help, the most theoretically crucial element, may be the hardest part of scaffolding for students to perceive or appreciate.

The authors are appropriately careful about what these numbers can and cannot prove. Because intact classes rather than randomly assigned individuals were used, instructional condition was completely confounded with class membership, meaning pre-existing classroom dynamics could partly explain the gap, even though ANCOVA controlled for baseline achievement. Both conditions were taught by the same teacher, which preserved consistency but raises the possibility of expectancy effects. The study took place in a single school with convenience sampling, the intervention lasted only three weeks, and perception data came solely from the treated group, so claims about motivation, confidence or engagement remain interpretive rather than demonstrated. The researchers also note they did not directly measure engagement or depth of conceptual understanding, so the mechanisms behind the achievement gains, while plausible and theory-consistent, are not confirmed.

Even with those caveats, the study matters. It provides experimental evidence from a context where teacher-centered instruction persists despite national policies, including Ghana’s Education Strategic Plan and the National Pre-Tertiary Education Curriculum Framework, that explicitly call for learner-centered, competency-based teaching. It moves beyond the simple pre-post comparisons that dominate the differentiated instruction literature by tracking proficiency-level transitions and student perceptions. And it suggests a concrete, replicable recipe for algebra teachers: diagnose readiness first, match tasks and support to each level, use worked examples, questioning, peer collaboration and continuous formative feedback, then deliberately withdraw help as competence grows. The authors call for longer interventions, follow-up assessments to test whether gains persist, multiple teachers, and multi-school studies to establish generalizability. But the core message is already legible: when algebra instruction meets students where they are and scaffolds them toward independence, achievement follows, and the students furthest behind may benefit most.

Subject of Research: The effect of scaffolding-based differentiated instruction on algebra achievement, mathematical understanding and problem-solving performance among senior high school students

Article Title: Scaffolding-based differentiated instruction and students’ algebra achievement: evidence from mathematical understanding and problem-solving performance

Article References: Ackon, J., Boateng, F. O., & Obeng, B. A. (2026). Scaffolding-based differentiated instruction and students’ algebra achievement: evidence from mathematical understanding and problem-solving performance. Frontiers in Education, 11, Article 1954830. https://doi.org/10.3389/feduc.2026.1954830

Image Credits: AI Generated

DOI: 10.3389/feduc.2026.1954830

Keywords: algebra achievement, differentiated instruction, scaffolding, mathematics education, problem-solving performance, Zone of Proximal Development, quasi-experimental design, ANCOVA, Ghana, senior high school, learner-centered pedagogy, student perceptions