Dec 04 2009

Teaching How Science Works

I and other science promoters have long advocated that science education needs to teach not just the current findings of science, but how science works – how we know what we know. Science is an intellectual  journey and a collection of methods, not a set of facts.

But facts are important too. Method without substance is hollow. Science is more of a dance between facts and ideas, and you need to know both, as well as how they interact, in order to do and understand science.

One conventional criticism of science education is that it emphasizes teaching facts and inadequately deals with process and theory. However, this criticism now appears to be outdated. Educators have gotten the word – teach process. In the UK this concept has been called HSW – How Science Works – and is a major part of the science curriculum.

Unfortunately, this has apparently not led to better science education, and perhaps even worse, all because of terrible execution.

(My standard disclaimer – I know there are excellent science teachers out there. I have had the privilege of having some in my own education. I am discussing the minimum standard, and not denying the existence of occasional excellence.)

HSW is coming under fire in the UK on two major points: First, emphasis on teaching HSW is taking too much time away from teaching traditional science content – so the balance isn’t optimal. Second, the execution of HSW has been bad overall, leaving students frustrated and not really understanding the methods of science. Rather, they are left with a vague sense of science as just another way of knowing, but don’t understand it’s strengths or how to distinguish science from pseudoscience. Students complain they feel like science is just another English comprehension course.

Another way in which a good sounding idea for science education has been poorly executed on average is the introduction of hands-on science. Ideas are supposed to be learned through doing experiments. However, textbook quality is generally quite low, and when executed by the average science teacher the experiments become mindless tasks, rather than learning experiences.

I have two daughters going through public school education in a relatively wealthy county in CT (so a better than average school system) and I have not been impressed one bit with the science education they are getting. Here is an example – recently my elder daughter had to conduct an experiment on lifesavers. OK, this is a bit silly, but I have no problem using a common object as the subject of the experiment, as long as the process is educational. The students had to test various aspects of the lifesavers – for example, does the color affect the time it takes to dissolve in water.

The execution of this “experiment” was simply pointless. They performed a single trial, with a single data point on each color, and obtained worthless results that could not reasonably confirm or deny any hypothesis. By my personal assessment, my daughter learned absolutely nothing from this exercise, and afterwards complained that she was becoming bored with science.

I repeated the experiment with her. First we thought of all the variables that could affect the outcome, and then controlled for those variables. We discussed various hypotheses as to how color could affect dissolving time. We then ran multiple trials and tabulated the results. We discussed some of the technical difficulties of the experiment – it was not completely obvious, for example, when the lifesaver “completely” dissolved – that last little bit seemed to have a half-life. We observed for possible confounders – such as air bubbles in the individual lifesavers. In the end we found that there was no clear relationship between the color and dissolving time.

In the classroom, however, all of these important details were glossed over. The students did a mindless experiment with uninterpretable results, and learned nothing. In fact, if they learned anything it was sloppy technique – they learned pseudoscience.

My daughters learn far more about HSW from Mythbusters than they do from science class.

Where is the disconnect? I think we need more involvement by working scientists, especially academic scientists who have a talent for teaching science. We also need a higher standard for science teachers – who should be required to take seminars and pass exams to qualify to teach science. It is simply too important an area to leave to those who do not have an adequate understanding of science. Great science teachers do a wonderful job of teaching science and filling their students with the wonder and awe of science. We should endeavor to make all science teachers great science teachers.

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