Tuesday, October 24, 2006

Why We Still Need Teachers

Thanks to Stephanie from Idealawg.com for the hat tip about this Rocky Mountain News column from Seebach. Seebach is commenting on a recent USC-Utrecht paper entitled Why Minimal Guidance During Instruction Does Not Work: An Analysis of Constructivist, Discovery, Problem-Based, Experiential, and Inquiry-Based Teaching here.

From the RMN: "The idea that the most effective way to teach students is to give them problems to solve, with only minimal guidance, has been around for half a century or so, under a variety of names. And it's always been wrong...It is bound to fail because of the way human memory functions." Huh? Seebach argues that most experiential learning will swamp lower ability students with so much information (working memory overload) that they may even know less after the "learning experience" than before.

Some of Seebach's and Kirschner & Co's critiques of discovery- or problem-based teaching have merit:

- working memory may often be overloaded when students are immersed with too much material
- students without explicit instruction may not learn

But their are weak points in their case as well - they admit that low and high ability students prefer problem-based learning to conventional / explicit teaching (improve motivation for learning, potential better memory for practice / concepts), but that, they suggest, is immaterial if the learning outcomes are not better.

So what do outcome studies suggest? When medical students are instructed with case-based instruction - they have superior clinical practice skills, but inferior basic science test performance. So what's the matter with this? Seeback and Kirschner deemphasize this result by mentioning, "But the negatives include lower scores on basic science tests, more study time and a pattern of ordering significantly more unnecessary tests at a much higher cost per patient with less benefit." But who would you rather have for a doctor - one who practiced medicine better or one who knew more answers on a pencil-and-paper test.

Actually, we can see the merit in explict instruction and discovery-based learning, and think parents and teachers should be skept if students' programs are touted as all-or-none. Discovery-based learning alone - is inefficient because many students will be clueless (or just copy answers from a neighbor) using a completely unguided approach. But, guided instruction-advocates should not lose sight of the fact that the ultimate goal of almost all learning should be its application to new situations or solution of new problems, or at least a fresh perspective on the present or the past.

Rather than a minimally-guided problem-based learning approach, we seen effective teaching when...

- The goals of teaching include facts, principles, process, and application
- Learning is interactive and not one-sided (wholly teacher- or student-focused)
- Learning from example and problem-based learning are not mutually exclusive
- The ties between theoretical and practical knowledge are explicitly looked for and taught if students don't get them.
- The limits and assumptions of information and subjects are considered, and applications to the real world, constantly reinforced.
- Teachers are taught to be very aware of working memory demands of material - so they are able to provide organization or scaffolding for students unable to assimilate information or problem-solving steps.
- Finally, practice and instruction in problem-solving are given, so students don't get all A's, but later flunk life.

Learning Last for Life - Review of Problem-Based Learning
Eide Neurolearning Blog: Learning That We're Wrong
Eide Neurolearning Blog: Easing the Work in Working Memory
Cognitive Apprenticeship / Math Forum
Cognitive Apprenticeship: Making Thinking Visible

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