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Wednesday, August 12, 2015

The value of critique in science education

One of the most difficult concepts to get across to science educators (e.g. professors in a biochemistry department ) is the idea that students need to be exposed to ideas that you think are incorrect and they need to be given the opportunity to make a choice. It's part of critical thinking and it's part of a good science education. Part of the problem is that there's a general reluctance to even teach "ideas" as opposed to facts and techniques.

There's an extensive pedagogical literature on this but university professors are reluctant to admit that there might be better ways to teach. While browsing this literature, I came across a recent article by Henderson et al. (2015) that makes a good case.
Five Arguments for Critique: The Nature of Science Case

Any attempt to explain why the material world is the way it is demands the development of explanatory hypotheses. When competing hypotheses or models exist—as they always will (Quine, 1951)—evaluation must take place by establishing which offers greater explanatory coherence, and which offers greater parsimony (Thagard, 2008). Confronted with competing models or explanations, critical and evaluative reasoning draws on domain-specific knowledge to make a justified inference about which ideas are to be believed. A growing body of research that would suggest that scientific reasoning is fundamentally probabilistic provides further justification for the significance of evaluation and critique in science (Howson & Urbach, 2006; Oaksford & Chater, 2007). From this perspective, scientific reasoning is best seen as an inference to the best explanation. This means that the rhetorical task confronting the scientist is not solely one of convincing other scientists of why their scientific account is correct, but also one of convincing them of why alternative theoretical accounts are wrong (Szu & Osborne, 2011). Constructing knowledge then, is not so much a product of one conception being replaced by another (e.g. Posner, Strike, Hewson, & Gerzog, 1982), but rather a process of weighing alternates and evaluating the balance of probabilities between two competing beliefs—in short ‘a dialectic between construction and critique’ (Ford, 2008). Shifting the balance of individuals’ beliefs, then, is reliant not on the credibility of a single idea (Belief A), but rather, on the ratio between the strength of evidence for Belief A when compared to Belief B (an alternative): in short, an assessment of which idea is more probable. As Oaksford and Chater (2007) argue the consequence is that in the initial stages of the emergence of any new idea ‘scientific inference is irremediably uncertain’ (p. 76).

Thus, all scientific accounts are the product of the resolution of difference. Argument and critique are required to resolve the difference between competing visions. In the case of science, the primary grounds for that resolution are empirical evidence. Commonly, new ideas in science are characterized by incredulity and are often difficult to accept. For instance, Andrei Linde, one of the scientists that developed the idea that the early Universe went through a rapid period of ‘inflation’ said of his own idea that, if anyone had tried to describe it to him 35 years ago, he would have answered ‘go home and tomorrow, when you are not very drunk, come to me and tell me this story again’ (Cookson, 2014). Likewise for the neophyte student of science, the idea that air has mass, that all matter is made of just 90 elements, or that objects can continue in motion without a force is contradicted by the evidence of their senses. Therefore, the real challenge for the teacher of science is not just one of convincing students of the validity of the standard scientific account but also one of convincing students that the alternate conception they hold is either flawed, inadequate or a misrepresentation.
I often refer to "teaching the controversy" and that's what I mean. It isn't good enough to simply expose students to the "right" ideas and hope that they will adopt them. You also have to explain why the opposing ideas are not right. Students have to learn this process of weighing opposing concepts and arriving at a position that is supported by evidence. It's called critical thinking.
Not surprisingly, students, who are never given the opportunity to engage in critique, can hardly be expected to develop an understanding of what a major element critique is to the practice of science. Nor can they be expected to develop a critical disposition and the procedural and epistemic knowledge—essentially knowledge of the methods and nature of science—necessary to identify the daily flood of pseudo-scientific claims. Knowledge of the methodological procedure science uses to minimize error, test its hypotheses and the epistemic constructs it uses are essential to justify science's claim to know. In the absence of critique, such elements of scientific knowledge are absent too from the science classroom. Thus, if students are to be educated to be ‘critical consumers of scientific and technological information’ (National Research Council, 2012, p. 24), then it is important that they are taught the basic elements of knowledge necessary to engage in a critical evaluation of scientific claims—many of which often have important personal consequences.
This all sounds so obvious when you see it written down like that but, in practice, we don't teach the nature of science. And what's even more scary is that many university professors don't even practice critical thinking of this sort in their day-to-day work. This is why you end up with scientists who don't know how to define a gene, don't understand the Central Dogma of Molecular Biology, don't understand basic concepts of biochemistry, and think that most of our genome has a biological function.

It's no wonder they don't want to teach these things to undergraduates and it's no surprise that they don't want to encourage debate and discussion in their classrooms.
If the questions were to be encouraged in the teaching of science, students would then be forced to respond to the critique of the teacher and their peers with arguments and counter-arguments of their own, constructing explanations, posing questions, and rebutting alternative ideas. In short, to engage in the natural process of epistemic vigilance. In the process of negotiation, such critiques may trigger an individual to consider their relevance, let the point ‘take hold in [his or] her cognitive environment’ (Schwarz, Neuman, Gil, & Ilya, 2003, p. 244), and subsequently appropriate or accept a new concept. More fundamentally, the ability to construct and ask questions is a cognitive act indicative of an epistemic stance towards knowledge that sees all claims to know as tentative—in essence, the hall marker of an evaluative and rational thinker.

Ohlsson argues that the construction of knowledge is dependent on a set of seven key epistemic discourse activities—describing, explaining, predicting, arguing, critiquing, explicating, and defining (Ohlsson, 1996) and that, while this taxonomy may be short, it is nevertheless, ‘surprisingly complete’. While some of these epistemic activities are central to the construction of an idea, that is, defining, describing, explaining, and predicting, others are core to the process of evaluation, that is, critiquing. Arguing is required both to propose an idea and to advance reasons for its weaknesses. Classrooms that omit argument and critique are, therefore, epistemically curtailed failing to provide an opportunity for all the epistemic activities necessary for the learner to construct new knowledge. Billig (1996) goes further to suggest that all thought is irreducibly argumentative as all statements embody within them the potential for contradiction and, without knowing the counter-positions, the meaning is lost.

Henderson, J.B., MacPherson, A., Osborne, J. and Wild, A. (2015) Beyond Construction: Five arguments for the role and value of critique in learning science. International Journal of Science Education 37: 1668-1697 [doi: 10.1080/09500693.2015.1043598]


  1. This is great idealism, but it's nontrivial in practice. Any practical advice?

  2. I don't think this is a new idea. I went to a private high school in 1960 that had this kind of classes and teaching. then went to a small college that had small discussion groups in the lab sections. My first day of Biology lab, we were divided into groups of three, tasked with the question, what is life? We were supposed to come up with something to present to the larger group. Many of the lab sessions involved open discussion.

    I'm not sure what to think. The devil is in the implementation.

    1. "What is Life?" is well-known to lead to endless arguments going in circles and ultimately bogging down. People disappear into the topic and are never seen again.

      Often in online discussions someone shows up who says "Before we can talk about evolving life forms we first have to define Life." Once that discussion starts I know I can absent myself, that nothing will be achieved. If I return, it is to angry, frustrated, haggard discussants.

      I'm surprised you survived that.

    2. To be fair to the profs, I think that was their point. My point is that all controversies are bottomless pits. It takes a great deal of skill to guide discussion. I've got mixed feelings about my experiences. But most of my education followed Larry's model.