Saturday, November 15, 2008

Necessary, Not Sufficient

Analyzing tides
If you have read a few of my posts, you'll note that I feel very strongly that students should have some real science experiences in their science classes. With more and more hands-on labs being pushed aside by virtual labs, I'm concerned about the nature of those labs. If simulations are used as lab substitutes, students lose an imporant opportunity to learn science.

They may learn about science, the vocabulary, laws, and theories of science, but they won't have the opportunity of understand the nature of science.

Nevertheless, simply using real experiments from the material world will not suffice. This fact is the second important conclusion of America's Lab Report (recommended reading). The first important conclusion is that science lab experiences must use the data, objects, and phenomena of the "material world" in their investigations.

What is required in addition to reality? I see two broad areas where additional requirements lie. The first area is in the presentation of the lab units, and the second area concerns how the lab fits into the course.

When preparing for a science lab experience, instructors should allow students to own, at least in part, the work they're about to do. Put the lab into context as solving a problem. Have students do some "research" on the problem. They might talk, read, or do some simple exploratory experiments. Don't just tell them the answer. Allow them to think about it, to mull it over. Then, they'll have some reason to do the lab other than you telling them to.

After the lab is completed, and students have done some analysis, get them together to talk about it. What conclusions have they made? Did all students come to the same conclusions? If not, why not?

In the post-lab post-mortem, you should ask students to identify what they observed directly and what they inferred. Find out how much they think can be inferred from observations. Talk about the quality of data. If possible, talk about data that did not fit expectations and discuss why. Was it experimental error, experimental design, or something else?

What you do before and after a lab can elevate or depress the value of the lab. It can change the lab from a dull, repetitive experience into an exciting investigation.

The second area for making a lab useful in a course requires that you properly integrate the lab into the course. Labs should not take place before a proper learning foundation has been laid. They also should not occur long after the topic has been introduced. Students should see the lab as a natural part of the course flow.

America's Lab Report focuses on four goals for integration.

Science lab experiences must (1) "be designed with clear learning outcomes in mind," (2) "be thoughtfuly sequenced into the flow of classroom instruction," (3) "integrate learning of science content and process," and (4) "incorporate ongoing student reflection and discussion."

Always realize that one of the clear learning outcomes that, according the the NRC, can only come in real lab experience is "understanding the complexity and ambiguity of empirical work." Inasmuch as possible, this should be a learning outcome of every science lab experience because lab time is limited and precious. This goal may not be realized with only a few opportunities to experience it. Don't squander those opportunities on simulations masquerading as science labs. Reserve use of simulations and other visualizations (interactive or not) for non-lab class time.

© 2008 by Paracomp, Inc., U.S.A. www.smartscience.netFollow this author on ETC Journal.


Oskar said...

Your description of the goals of labs hits home with me. In the class I'm taking now it is very hard to feel that we really learn much from our labs. What we are trying to do often isn't clearly defined. We are told to perform some kind of experiment or demonstration but there isn't enough time to really analyze what it means. There are too many students in the lab so it's often too noisy and crowded and the teacher is spread too thin to be of real help. The time is often filled with trying to do too many things. It would be better to do just one thing well and have time to analyze it. Instead the teacher has to tell us that if we don't have time to finish, just make notes on what we managed to do. My partner and I sometimes ask each other why we are doing this, and we try to guess. This isn't helping us to understand science, even though we were interested in this class when we started.

Harry said...

America's Lab Report writes about a "typical" lab experience as being poor. You've described some aspects of that experience.

Your instructor does not control everything that goes into your lab experience. In your case, for example, class size is not under the instructor's control.

Still, teaching requires organization and effort to bring what you can to the students. Make no mistake; it's not easy. Teachers are not usually trained in how to prepare labs, integrate labs into their courses, and handle all of the problems associated with presenting labs. The ones that succeed have mostly figured it out by trial and error along with help from colleagues.

Basically, science is simply figuring out what makes the world tick. Doing that can be fun. Scientists have specific thinking methods they use when doing this sort of work. Mostly, they insist on clear experiments with reproducible results. They compare their work with that of others. They take nothing on faith.

Too many students have poor science experiences beginning around grade 6 and continuing into college. As a result, many miss out on a career that they would have loved -- given the chance.

Sue said...

Thank you for stopping by my blog. I am a chemistry teacher and interested in teaching science in the most effective way to my students. Online students can be very motivated and many don't have the opportunity to take a traditional course. Whether face-to-face or online, I want to find a way to "turn on" introductory students to how science can relate to the world around them. I love it when I have a student tell me that "this stuff is actually interesting" in the middle of the semester.

I find incorporating labs into an online course interesting. Many students treat labs as a cookbook exercise and don't really analyze what they are doing and how it relates to what they're learning in class. I am always looking for ways to lead them into thinking about what they are doing.

Harry said...

Sue, thank you for stopping by.

I was once a chemistry professor at a very large private university, Northeastern University.

One way to engage students is having them do an experiment with unexpected results. Do that early in the course, and you may have many "hooked" on science.

My son taught high school science, and I helped out as his lab assistant quite often. Once, for physical science (he also taught chemistry), he provided the canonical pendulum experiment with different lengths and masses.

When a student group came to him and worried that their data was wrong because the period didn't change when the mass did, he had a great learning moment.

Students must learn that science is all about finding out, that certain thinking tools are employed in finding out, and that finding out can be fun, social, exciting, and rewarding.