20 Oct 2009 17:30
The following subheadline on the Scientific American website caught my eye today (and not only because of the missing period):
New research makes the case for hard tests, and suggests an unusual technique that anyone can use to learn
I may be a bit thick, because neither the article nor the research paper it mentioned suggested any unusual technique to me. But this was better than my last wild goose chase reading episode, when I vainly sought a footnote on a cereal box (there was a dagger: †, but no footnote. Can you believe that?).
Henry Roediger and Bridgid Finn, the Scientific American article’s authors, write that researchers Kornell, Hays, and Bjork found that “learning becomes better if conditions are arranged so that students make errors.” There’s that pesky word “better.” Better than what? The eternal unanswered question. My guess is that Scientific American is reporting that Kornell et al. have found that learning under a) conditions arranged so that students make errors is better than learning under b) conditions arranged so that students do not make errors. In other words, that the researchers found errorful learning to be better than errorless learning. Not that it’s a bad article, but it would be nice if Roediger and Finn had stated what they’re reporting a bit more clearly. (This is why I give writing assignments to my statistics students. By the end of the semester, they better learn not to use adjectives like better without answering “Better than what?”.)
Anyway, Kornell et al. do mention errorless learning in their paper, recently published in the Journal of Experimental Psychology: Learning, Memory and Cognition® (yes, the name of the journal is a registered trademark), but they don’t study it. The abstract notes that they examine the question of “what happens when one cannot answer a test question—does an unsuccessful retrieval attempt impede future learning or enhance it?” Kornell et al. didn’t exactly examine this question either, because they didn’t (and possibly couldn’t) isolate what part of the learning in their scenario was “future” learning. In addition, they only studied learning after wrong answers, so one must be careful not to assume their research sheds light on getting test questions wrong vs. getting them right. (Suppose a researcher reported that “Student learning among African-Americans is enhanced when they are given test questions they cannot answer.” If the researcher only studied African-Americans and made no comparison to other populations, the reported finding might easily be misinterpreted.)
What Kornell et al. did was compare two scenarios for learning previously unknown information. One scenario was unsuccessful retrieval attempts (the students were asked to provide the not-yet-learned information as answers to test questions, and they answered incorrectly). In this scenario, the retrieval attempt was followed by feedback that included a brief presentation of the new information (i.e., the correct test question answer). The second scenario was a longer-lasting presentation of the new information with no retrieval attempt (the students were not asked to answer a test question, and it’s unclear in some of the experiments whether the students knew what kind of test question they would later be asked). Not surprisingly, unsuccessful retrieval attempts enhanced learning (as measured by scores on a test containing questions like those in the retrieval attempt), when compared to presentation of new information with no retrieval attempts. Despite the Scientific American article’s subheadline, this research makes no case that “hard tests” are better for learning than non-hard tests. They may be, but this research doesn’t help us figure it out. The research does support the value of tests, hard or not-hard, so long as there’s feedback with the right answer.