Thursday, June 23, 2011
A recent study from University of Washington professors compared two approaches for teaching large introductory biology classes: 1) traditional lecture method, and 2) “active learning” without lecture. Eliminating lecture does not in itself improve teacher-student ratios. Indeed, some have said it doesn’t matter whether one lectures to 20 students or a thousand.
What is important is to address the question of what happens to educational quality if you reduce the number of teachers. There is certainly no evidence that increasing the number of students in a lecture hall will improve teaching effectiveness, and in fact the opposite is likely. Statistically, increasing class sizes in lecture courses has a disproportionate deleterious effect on socio-economically disadvantaged students. So, as number of teachers decreases in response to economic necessity, we can expect the educational gap to grow between advantaged and disadvantaged.
So, how should educators respond to having more students and fewer teachers? The educational literature has been building for decades toward the conclusion that lecturing is a poor way to teach. We teachers know about many alternative “active learning” strategies, but just don’t use them much, because lecturing seems so intuitive and for most of us, it has become a habit. And lecturing is the environment in which most of us were trained.
In the U. Washington study, the professors compared grade performance in classes based on lectures with classes based on active learning. The type of active learning they used included pre-class reading quizzes, daily multiple-choice “clicker” questions, a peer group instruction format that included so-called “constructivist” learning exercises, and weekly practice exams. Also, they adjusted learning requirements to require more creative and critical thinking, since most college students have little experience with higher cognitive tasks of synthesizing and applying learned material in new contexts (as specified in Bloom’s taxonomy of learning). The learning activities went beyond the lower levels of learning vocabulary and understanding of concepts.
Large student populations were involved for both comparison groups, and the classes studied spanned several semesters. Student performance was measured in terms of difference from the predicted performance based on college grades prior to entering this biology class and SAT scores (which are highly reliable predictors, based their previous analysis of five year’s of class data). This analysis also revealed a reliable prediction that disadvantaged students were twice as likely to fail this course than non-disadvantaged students.
Not surprising (to me at least) was the consistent result of better final grades in the classes that had active learning instead of lectures. The benefit was especially noticeable on exam questions that demanded higher-level thinking. Moreover, the disadvantaged students improved disproportionately.
The authors did not examine possible explanations for why active learning yielded better results than lecturing. I think the explanation is obvious, based on what I know about mechanisms of learning and memory. First, learning from lectures requires sustained paying attention, but a whole generation of multitasking students has emerged who are not very adept at sustained attentiveness. Accordingly, the short attention spans of these students make it difficult for them to be engaged with the lecture content. Engagement lies at the heart of effective learning.
Secondly, active learning requires more engagement because the students have to “do something” instead of just listen. They have to find, assimilate, and use information to solve problems — all of which enhance understanding and are effective memory rehearsal strategies. The social dynamic of student learning teams facilitates these activities. It is much harder to drift off task, daydream, or sleep in class when a student has to interact socially with peers to perform a learning activity.
These ideas have been advocated for several decades. But now, it seems imperative for teachers to use these approaches in an age where there will be fewer teachers and where more students are unable to benefit from lecturing. This requires for many teachers a sea-change in teaching attitude and strategy. It is no longer suffices for a teacher to be a source and dispenser of information. Information already exists in many places, text books, Web sites, and videos, often in better presentation form than a typical teacher can produce. Even the expected role of teachers in explaining everything is problematic. Students remember much better that which they have to figure out. Working in groups makes it easier to figure out difficult material. Students can often explain things to each better than teachers can because teachers have more difficulty in knowing why students are having a comprehension problem.
The teacher must become a manager of learning activities. This means structuring in-class time so that students work collaboratively on learning activities. Students also need homework that gets beyond “busy work.” And, as I have been advocating for some time now, students will benefit from more frequent testing, especially under lower-stakes conditions.
Effective managers are those who can “scale up” to manage more and more people. We can’t wait for a new generation of teachers and professors. We need professional development programs now that emphasize management of student learning.
Haak, D. C., et al. 2011. Increased structure and active learning reduce the achievement gap in introductory biology. Science. 332: 12131-1216.
Tuesday, June 07, 2011
The “best” teachers are the one’s who make learning easy. At least that is what the poorer students say. They may be wrong. The popular belief that it is easier to learn things that are easy rather than harder is also probably wrong. Easy material may not elicit enough attention and engagement to produce lasting learning. So, educators may need to re-think the whole notion of what makes a teacher effective. Making learning easier makes the teacher more popular, but that does not necessarily translate to real student achievement.
Kent State psychology professors have just reported a study of this matter with college students. They find that when students think something is easy to learn they may have only a superficial level of learning that does not last much beyond the next test. Just staring repeatedly at learning material is not nearly as effective as forcing retrieval of the information. Moreover, students can develop an easy-learning attitude that leads to bad study habits and an ineffective learning style.
Other research that I have summarized elsewhere shows that students likely do not know material as well as they think they do. That is, if they perceive they have “got it in the bag,” they may find out they are sadly mistaken at test time. Likewise, students tend to quit study too soon, thinking the material was easy and they have learned it. In fact, repeatedly studying material you assume you know makes it more likely that you really do know it.
Easy learning, as in a single cramming session, is deceptive. It is not nearly as effective as the harder learning of spreading out the study over many days and weeks. The self-testing under the delayed conditions is much more effective precisely because it is harder to recall material learned days ago .
In the Kent State studies, college-aged students were asked to study for a week a pack of 48 flashcards that paired Swahili vocabulary words with their English translations. The students were divided into two groups and in both groups, students asked to use a mediator — word, phrase or concept — link both words of a pair. Students in one group were given practice quizzes where they were shown a word and asked to name the other member of the pair. An examination at the end of the week revealed that the practice-quiz group performed much better on the final exam, especially if they were asked to recall the mediator.
In a study recently reported at an American Educational Research Association meeting in by Katherine Rawsom at Williams College, students studied 35 Swahili-English word pairs on flash cards. The students were asked to practice until they got the vocabulary correct using either the entire stack or five stacks of seven cards each. Researchers instructed students to study the flashcards until they had gotten each translation correct either once, five, or 10 times, before taking a final quiz a week later. Getting the stack correct five times was three times more effective for the final quiz than the stack was correct only once. Also, study of one big stack was better than five little ones.
Students had predicted just the opposite. They expected studying smaller groups of flashcards would be more helpful than studying the big stack, and they expected no real benefit from studying cards more than once. They remembered about as many words as they expected to recall when studying the entire pack, 43 percent to 46 percent. Yet those who had studied the small stacks expected to remember nearly 60 percent of words yet recalled only 17 percent. In general, students were incorrect in two ways: 1) they give too little value to learning strategies that are difficult (using multiple sessions on the big stack), and 2) they give too much credence to strategies that were later documented to be less effective.
The deceptiveness of ease of learning was reinforced in a study reported in Psychological Science by Nate Kornell and collaborators at three other universities. Participants were asked to predict how easily they would remember vocabulary words after studying them once or multiple times. Some of the words were presented in the standard font size on the person’s computer screen, while others were presented four times larger —something that makes the text feel easier to process but prior research shows does not improve memory. In addition, for some words, participants were told they would be allowed to study more than once.
The participants uniformly predicted that studying the words in larger font would help them remember more than studying the words multiple times. In fact, increased font size did nothing to help them, but studying even once more improved their recall of the new words.
Some school authorities have it all backwards. They want teachers to make the material as easy to learn as possible. I don’t mean to excuse teachers whose instruction is disorganized and confusing. But teachers who challenge students with difficult material and assignments, as well as frequent testing, are actually doing their students a favor. They are just the opposite of the accusation of being “bad” teachers.
This also relates to “dumbing down” the curriculum, which may actually interfere with learning. If we raised standards, we would find that students have to get more engaged. Better learning is predictable. I think that when learning is difficult, learners are obliged to be more engaged. And it is the engagement that achieves lasting learning. Of course this only works for students who are motivated to learn.
Cavallos, M. (2011) How testing improves memory. Science News. November 6th, 2010; Vol.178 #10
Kornell, N., Rhodes, M. G., Castel, A. D., & Tauber, S. K. (2011). The ease of processing heuristic and the stability bias: Dissociating memory, memory beliefs, and memory judgments. Psychological Science. 22(6) 787 –794
Sparks, Sarah D. (2011). Studies find “desirable difficulties” help students learn. Education Week, April 26.