Learning & Memory | Aidan McDonagh | TEDxBangkokPatanaSchool

Summary

Aidan McDonagh, a mathematics teacher, reflects on a common classroom problem: students may understand a topic when it is taught but struggle to recall it weeks later. Early in his training, he was taught that teaching for understanding was the key to learning. His experience—including students forgetting Pythagoras’ theorem after a carefully planned lesson—led him to question whether understanding alone was enough.

Drawing on the memory theory of psychologists Robert and Elizabeth Bjork, McDonagh describes learning in terms of two factors:

• Storage strength: How well a memory is connected to other knowledge. This is related to understanding.
• Retrieval strength: How readily and effectively a memory can be recalled.

A memory can have strong storage strength but weak retrieval strength. For example, someone may have meaningful memories of their primary-school classmates but rarely recall their names. The memories may still be stored; they are simply difficult to access. Prompts—such as seeing a class photograph—can make recall easier.

McDonagh argues that students need more than clear explanations and opportunities to understand a concept. They also need regular practice retrieving it. Each successful act of recall strengthens retrieval and makes the knowledge easier to access later. For example, students should be asked to recall and apply Pythagoras’ theorem after the initial lessons, rather than assuming that understanding it at the time of teaching guarantees lasting memory.

He contrasts this approach with cramming, which concentrates recall practice just before exams, and with passive revision methods such as highlighting notes. Retrieval practice, he argues, should be a regular part of learning throughout primary, secondary, and further education—not something reserved for exam preparation.

Suggested Practice

• For teachers: When planning a lesson, consider not only how to explain the material clearly but also how students will be prompted to remember it later.
• Schedule recall over time: Revisit learning after a week, a month, and a year rather than relying on a single lesson or last-minute revision.
• Ask students to retrieve and apply knowledge: Use quizzes, questions, or other recall activities to bring previously learned material to mind.
• For students: Test yourself on what you have learned instead of relying only on rereading or highlighting notes.
• Treat assessment as a learning tool: Short, regular checks can help strengthen memory, not merely measure what students know.
• Engage with cognitive science: Teachers, learners, and other education stakeholders should use research on memory and learning to inform educational practice.

Speakers and Sources Featured

• Aidan McDonagh — The speaker, discussing his teaching experience and research.
• Robert and Elizabeth Bjork — Psychologists whose two-factor account of memory—storage strength and retrieval strength—is cited by McDonagh.