During my years of teaching the Science curriculum has gone through many changes. Unfortunately, the one that was in place for the years before I retired was not one of the best. In my opinion the pre-high school science curriculum should be far less content oriented and more process oriented. Especially in the Intermediate (Middle) grades when students are evolving into more rational thinking, the emphasis should be more on scientific method than on any content. Not only is it critical to a proper understanding and perspective towards science, but it also reinforces the developmental changes and intellectual curiosity of the student at this age.
There was a time when this was understood and applied, roughly during the mid 1990s. It was one of the few bright spots in Ontario’s Outcome Based Learning initiative. When OBL was scrapped for some reason a lot of the process based learning outcomes went out with the bathwater, and a proper introduction to scientific method was one of the casualties.
The best intermediate science curriculum I ever saw came from the Lincoln County B of Ed. in around 1990. There was a 2” binder for each of grades 7 & 8. The grade 7 curriculum was themed around physical sciences and grade 8 around biological sciences. But the thing that made these special was that each started out with a comprehensive unit about scientific method and that process was reflected in all of the units that came afterwards. It introduced the ideas of what a hypothesis was, or what the difference between correlation and experimental data. It introduced the idea of different types of variables and why controlling them was important. It also introduced basic equipment, so that students would know how to use a triple beam balance and understand the difference between force, weight and mass. None of these skills, or the many others that come under the banner of basic scientific method, were contained in the content based science curriculum that I was forced to deliver in the last years of my teaching.
Additionally the entire program could be conducted without a textbook, as each teacher guide page was accompanied by several student work sheets that were all excellent. This might be one of the reasons for its demise and one should never underestimate the influence of the textbook publishing industry in educational policy. Text book publishing is a billion dollar industry and is largely responsible for the standardized testing craze, as they publish those as well. However, back to the matter at hand...
One of my favorite activities in this program was to have students calculate the unit cost of theatre popcorn. I would save up a number of popcorn bags from movie theatres and bring them into class. Then we would make popcorn and figure out its cost per kilogram and per pound. It was a fun activity, but required the concepts of net, tare and gross weight, how to use a triple beam balance and how to convert measurements. When I recently visited a grade 8 class and ran this program I found that each one of those skills had to be taught as they’d never been exposed to them in their current curriculum. The cost, by the way, works out to about $68 per pound, which is interesting to compare to other items. Students would go on line and discover how much quality steak, lobster and caviar cost, being amazed to find that theatre popcorn is more expensive than all but the most exclusive caviar.
Another of my favorite activities was the basic pendulum experiment, used to teach the manipulation and control of variables, forming a hypothesis and planning a valid experiment. It starts with the question, “What factors (variables) will influence the frequency of a pendulum?” A bunch are listed, including amplitude of the swing, mass of the bob and length of the swing. We did one together as a class in order to model the proper design and write up of an experiment, paying attention to things like replication, observation charts and proper wording for conclusions. Students then worked in small groups to plan and conduct the other experiments until they can show which factors (length of the string being the only one) did or didn’t result in frequency change. Once they established length as being the only relevant variable, they were required to investigate further by using many different lengths, recording the data and plotting it on a graph, thus showing that there was a mathematical relationship between length and frequency.
We did many similar experiments, some involving levers and leverage, or calculating the height of a tree using shadows and ratios. The idea was not to teach a specific content, such as memorizing the Periodic Table, but rather to encourage the proper understanding and application of scientific method and process. Not only did the students end up doing a lot of experiments, but they also were exposed to a variety of scientific equipment.
I want to briefly mention two other activities used in this approach to science. The first involved giving pairs of students a small slip of paper on which was written CARBON DIOXIDE and a stoppered test tube full of water. Students were then told that all of their discoveries had to remain secret, and as they progressed through the activity they could only relate their discoveries to me in a whisper. They were then told to use the two items and try to discover something that was problematic. It doesn’t take long before you begin to hear “What the…” as the students look through their test tubes at the slip of paper. What they are noticing is that, as seen through the water, the word carbon flips upside down while the word dioxide does not. Each pair comes up to tell the teacher and after a while the teacher announces the problem to the class and tells the students that it is their job to find out why this is happening. I would tell them that once they understood the reason it would be an “aha” moment and they were still required to keep the secret. The class would talk briefly about the kinds of experimentation that could be conducted and the kinds of variables that could be changed. Then students are let loose to experiment. Eventually you get the “ahas” and students begin to come up with the answer. (I won’t tell you what it is here. You can try it yourself if can’t figure it out in a mental experiment.) That’s all there is to it. There’s very little written work in this activity, other that a short personal response about what the student learned from the experience. But the activity is extremely instructive, …again without the need for specific content.
Another activity was about the integrity of research and revolved around a great Internet site which I believe is still active. I told the students that the lesson was about safety and that they were going to examine a dangerous chemical called dihydrogen oxide. (Once again they were told that if they had the aha moment to keep it to themselves.) They then had a work sheet with general questions on it and were directed to the web site in order to find the answers. The web site had many facts on it such as that dihydrogen oxide was responsible for more deaths every year than any other chemical. Students would dutifully answer the questions on their sheets, but eventually a few would clue in to the fact that dihydrogen oxide is, in fact, water. Once the class as a whole was enlightened it would lead to a discussion about facts and their interpretation, along with the importance of verifying information from the Internet. There are many other similar activities in the Internet, but this one is simple and not in any way controversial.
So, these initial units in grade 7 & 8 provided an essential grounding in scientific method and other related concepts. Later units reinforced and expanded these. Behavioural concepts were studied using mealworms, and in several years I even had students design and conduct simple, harmless psychological experiment, sometimes using subjects from younger grades. These were always tremendously fun for all concerned.
One of my favorite applications did not come from the LCBE curriculum, but was an elaboration of an idea from a conference I attended. This was the idea of a CSI unit, where the students were given a murder mystery to solve. Clues were provided to them, on which they had to do research and experimentation. For example a cup of coffee was found at the scene and the police recorded the temperature of the coffee. Students were given information about the temperature at which it was brewed at the local Tim Horton’s and how far away it was. They then had to measure the rate of cooling of coffee in a Tim Horton’s cup to see whether it matched the time line given by the suspect. Other evidence included materials that had to be looked at under a microscope and even tire and shoe tracks that had to be compared to real life data. (The “guilty” party was a real person in the school.) This CSI unit ended up being combined with all of the other subjects from Math to Language Arts to Geography in a vast integrated unit which consumed a major part of each day for several weeks. Setting up integrated, multi-subject units like this one is something that I’ll discuss in a future entry as it was definitely the highlight of my teaching career.
I strongly believe that students need an ability to critically evaluate the massive amount of information that they encounter every day through the media in the internet. I know that half the time I hear a study stated on the radio or on TV, I look at it and shake my head because I can see the flaws in the science. Understanding scientific method, statistics, and logical fallacies are central skills, not peripheral. In my opinion they need to be stressed at the age that the biggest leap in rational developmental growth takes place, which is early adolescence.