Saturday, April 11, 2009

Proving Theories

F. W. Westaway's book, "Science Teaching," is full of excellent advice for science teachers and is just a pertinent today as in 1929 when it was published. Here's a nice nugget from the footnotes.
We may perform an experiment to verify a law, or to confirm the possibility of the truth of some hypothesis. But if we could "prove" theory to be "true", the theory would become identical with objective reality and cease to be "theory" entirely.
This simple prose explains why we can only disprove hypotheses and never prove them. We only "confirm the possibility of truth."

In the Smart Science® system, we have the option for teachers of presenting pre-written hypotheses or predictions to students. The students collect data from the prerecorded real experiments and/or from their hands-on experimentation and use those data to eliminate or disprove individual hypotheses or predictions.

It's quite possible that more than one hypothesis remains. Depending on the list, all may be eliminated. In any event, students are expected to defend their choices when writing their lab reports.

© 2009 by Paracomp, Inc., U.S.A.
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Tuesday, April 07, 2009

Some Advice on Teaching Science

Frederick W. Westaway gives lots of advice on teaching science. Regarding experiments or labs, he provides plenty as well. Here is some.
Beware of the pseudo method of discovery. "Pour H2SO4 on granulated zinc, and you will discover that hydrogen is given off "!

Beware of verification methods. "Show that ferrous ammonium sulphate contains one-seventh of its own weight of iron." This is simply asking for the evidence to be cooked.

When a boy works an experiment, keep him just enough in the dark as to the probable outcome of the experiment, just enough in the attitude of a discoverer, to leave him unprejudiced in his observations.

Do not adopt the heuristic extremist's principle that a pupil must not be permitted to take anything second hand. Life is too short.

Do not make the fatal mistake of thinking that all boys have an instinct and imagination for making discoveries, or can be made first-class workers in the laboratory. In any average science class, be satisfied with 25 per cent of α's, 50 per cent of β's, and 25 per cent of γ's, but do not stick labels on the γ's for all the world to recognize them.

Teach boys the virtue of recording all mistakes as well as successful results. Tell them that all science workers make mistakes: that that is almost the normal thing! Faraday, the most resourceful experimenter that the world has ever seen, said that he learnt far more from his mistakes than from his successes. A boy's laboratory note-book containing no mistakes is never a true record of the work he has done, and it is morally wrong to let it be presented as if it were such a record.

The pupil's notes should tell a plain tale to people who were not present when the record was made, and they should be written up in the laboratory, in ink, when the work is in progress.

In the laboratory, a teacher should have everything in readiness before a lesson is due to begin, including instructions as to the procedure to be followed in all experiments to be performed. If these instructions are given orally, they are forgotten; dictated, they take up much time; written on the blackboard, they are not permanent, and have to be written up again for a future lesson. Typed instructions answer best.

Whatever general method of teaching you adopt, do everything possible to economize time. It is bad economy — it is worse, it is sheer waste of time, to say nothing of a lack of ordinary teaching intelligence to worry beginners about, say, the difference between density and specific gravity, or " pressure at a point ", or the number of stamens in a flower.
Of course, Westaway, in 1929, had no idea that simulations would become popular 80 years later. As you read his words, you have to conclude that he would not have liked his students doing simulations in place of the real thing. Demonstrations may not allow students to do the experiments with their own hands, but at least they're real. With a good teacher, they can provide a good learning opportunity, provided that the class is not too large.

© 2009 by Paracomp, Inc., U.S.A. www.smartscience.netFollow this author on ETC Journal.

Thomas H. Huxley Speaks to Us

Frederick W. Westaway, in 1929, spoke clearly to us today about science education in his book, Science Teaching. He quotes Thomas H. Huxley, also known as "Darwin's bulldog," at length about science education. Huxley foreshadows Piaget's constructivism in 1869!
Huxley said: "It appeared to me to be plainly dictated by common sense that the teacher who wishes to lead his pupils to form a clear mental picture of the order which pervades the multiform and endlessly shifting phenomena of nature, should commence with the familiar facts of the scholar's daily experience; and that, from the firm ground of such experience, he should lead the beginner, step by step, to remoter objects and to the less readily comprehensible relations of things. I conceived that a vast amount of knowledge respecting natural phenomena and their interdependence, and even some practical experience of scientific method, could be conveyed, with all the precision of statement, which is what distinguishes science from common information. And I thought that my plan would not only yield results of value in themselves, but would facilitate the subsequent entrance of the learners into the portals of the special science."
You have to wonder why education has the continual rediscovery associated with it. If Huxley clearly enunciated this principle of founding learning on the experience of students, why did Piaget have to rediscover it?

This concept of beginning with what students already know from their experience has become the bedrock of many teachers today. Yet, it's treated with the attitude that it's something new when it was truly explained 140 years ago!

© 2009 by Paracomp, Inc., U.S.A. www.smartscience.netFollow this author on ETC Journal.

Canon Wilson

I am privileged to be reading Science Teaching by F. W. Westaway, published in 1929. In it, he summarizes the history of science teaching and begins by dividing this subject into two eras: before and after 1867. Why pick that date? That's when Canon Wilson wrote extensively about teaching science and broke with millennia of tradition. The following quote comes from Westaway quoting Wilson.

The lecture may be very clear and good; and this will be an attractive and not difficult method of teaching, and will meet most of the requirements. It fails, however, in one. The boy is helped over all the difficulties; he is never brought face to face with nature and her problems; what cost the world centuries of thought is told him in a minute; his attention, understanding, and memory are all exercised; but the one power which the study of physical science ought preeminently to exercise, the power of bringing the mind into contact with facts, of seizing their relations, of eliminating the irrelevant by experiment and comparison, of groping after ideas and testing them by their adequacy in a word, of exercising all the active faculties which are required for an investigation in any matter these may lie dormant in the class while the most learned lecturer experiments with facility and with clearness.
How ironic to see very similar ideas being written 142 years later by the National Research Council in America's Lab Report. What Wilson is referring to is the value of experimentation in learning. In order to gain the true benefits of science education, students must confront complex and ambiguous situations with true real-world data that is not clear-cut and obvious.

"Experimenting" with equation-derived data is insufficient. It's even wasteful of time that could be spent experimenting with real-world data.

Students must a) experiment, and b) collect data from the material world. Providing a safe, efficient, and inexpensive means to this end has been the driving force behind the creation of the Smart Science® system. No other organization has put the necessary time and effort into such a creation. They all take the easy way out with cartoon-like simulations that give you the same data always. There's no imperative to collect data point by point in a simulation. It makes no sense.

To put the case very bluntly, the time reserved in a science course for laboratory experience must not be replaced by simulations. They are destructive of learning science if used in this fashion. Simulations, like any tool, must be used properly to have a positive outcome. Students have to know that the simulation they're running is not an experiment or a "lab." They must know that it's an artist's conception of certain equations that represent the current consensus of scientists and that even so, they may contain errors or "bugs."

If your data source is the real world instead of algorithms, then these problems vanish.

The Smart Science® education system blends prerecorded real experiments with safe, effective, and inexpensive hands-on experiments to provide an optimized learning outcome. No other system available today can make that claim.

© 2009 by Smart Science Education Inc., U.S.A. www.smartscience.netFollow this author on ETC Journal.