Helping Students Learn in the Sciences

Students often struggle in the physical sciences. Not only does one have to be proficient in mathematics. A pupil also needs to understand concepts and some of these are quite challenging. There are indeed instances in which a student is clearly capable given his or her aptitude in math and reading and yet, still finds either chemistry or physics as tough subjects in school. It is therefore necessary to look at ways that can help students overcome difficulties. As Susan Carey has pointed out, "All good teachers have always realized that one must start “where the student is”... ...Now we understand that the main barrier to learning the curricular materials we so painstakingly developed is not what the student lacks, but what the student has, namely, alternative conceptual frameworks for understanding the phenomena covered by the theories we are trying to teach."

There is nothing inherently wrong with how young children understand their physical world. After all, scientists also reshape how they view nature as they continue to hypothesize, experiment and discover. The atomic theory is one good example. What is important to realize is that there is indeed this progress as concepts are refined from what is learned in the early years to what is tackled today and in the future. Carey provides the following example to illustrate the challenge of conceptual change:

...the teacher may ask the students to imagine the weight of a pile of rice, a piece of rice, half a piece of rice, half of that, and so on. Most of the students will agree that one reaches a point where the rice weighs 0 grams. Then the puzzling question can be raised: how can a pile of rice weighing 2 grams be composed of many pieces weighing 0 grams?

Knowing "where the student is" is crucial for teachers but it is equally important that students also know where they currently stand. Thus, some of the promising ways of supporting students learn in the sciences involves self-examination. Hofer and coworkers have recently examined a battery of interventions that can greatly help students overcome the challenges of conceptual change in the physical sciences. This approach called the "cognitively activating instruction" (CogAct) includes the following ingredients:

  • Generating Solutions to Novel Problems Prior to Instruction (Productive Failure)
  • Inventing With Contrasting Cases
  • Comparing and Contrasting
  • Metacognitive Questions

This blog has descibed previously another study that looks at how these methods enhance learning. In Problem Solving Before Instruction, the work of Loibl, Roll and Rummel has been  highlighted. The experiment performed although quite limited already shows great promise in helping students learn new concepts. The new study by Hofer and coworkers deals with a more elaborate setup. Lessons on mechanics are given during a 10-12 week period to 172 students enrolled in 10th grade Gymnasium classes in Switzerland. The Gymnasium is the highest academic track which is comparable to the Advanced Placement (AP) courses taken by high school students in the United States. These classes are therefore taken by students who already have demonstrated proficiency in their primary and early secondary years. The instructors who participated in this experiment either hold a masters or a doctorate degree in Physics. Thus, with the design, the effect alone of the "cognitively activating instruction" can be carefully measured. Examples are provided and here is one for the Productive Failure part:

Above copied from
Hofer, S. I., Schumacher, R., Rubin, H., & Stern, E. (2018). Enhancing physics learning with cognitively activating instruction: A quasi-experimental classroom intervention study. Journal of Educational Psychology. Advance online publication.
http://dx.doi.org/10.1037/edu0000266


Most student will not get the correct answer, that is, the force meter will still display the same amount of force, 10 N, when an additional weight of 1 kg is placed on the other side of the force meter. It is this failure that helps wake up the students to the new concept of Newton's third law.

The results of the experiment illustrate the positive effects of "cognitively activating instruction", CogAct, especially with female students who score high in IQ tests:

Above copied from
Hofer, S. I., Schumacher, R., Rubin, H., & Stern, E. (2018). Enhancing physics learning with cognitively activating instruction: A quasi-experimental classroom intervention study. Journal of Educational Psychology. Advance online publication.
http://dx.doi.org/10.1037/edu0000266

What is truly amazing is the significant way CogAct erases the gender gap for female students with an intelligence score above the 75th percentile. However, the impact on problem solving for males with high intelligence is not demonstrated and generally, why CogAct effects on students with lower IQ needs are small needs to be further examined. 



Comments