Hands On Experimentation as a Teaching Tool

The real world is hardly cut and dried, it is full of uncertainties, probabilities, and hypotheses to be verified. Introducing this into a classroom though, is hardly straightforward. Even adults are sometimes unprepared to deal with uncertainty. And young children are even less well equipped to handle uncertainty.

The Common Core State Standards introduce Statistics & Probability in grade 6, and the Next Generation Science Standards introduce the concept of measurement error and multiple measurements at about the same time.

Laboratory experiments provide a strong example of measurement error and probability and their interaction with other subjects. Laboratory experiments can be introduced just after probability and measurement error.

Hands on work, laboratory work, practical work, it has many names. It has even more benefits. Perhaps so many benefits that it is sometimes difficult to prioritize them for a given situation^1,2. Further many of these benefits are distinct from standard classroom instruction and as a result at times "outcome measures consisted almost exclusively of paper and pencil achievement tests that were often poorly linked to the laboratory activities."

Not only do we need to be careful in constructing the laboratory component of our instructional content, we have to be careful how we access its effectiveness. Designing each of these requires a familiarity with scientific experimentation and the scientific method.

We have talked about the contextual sensitivity of knowledge, and the value of presenting the same material from multiple viewpoints over time. The laboratory experiment exercises both of these principles.

The first hand exposure to scientific principles provides a new path to insight on classroom material. At least as importantly, it necessitates dealing with real world issues such as what it means to validate or invalidate a hypothesis, dealing with experimental data, presenting experimental results, and drawing conclusions from experimental results. Entire books have been written on these topics ^5,6.

Perhaps the most important of these, and one of the most difficult to grasp, is the need for experimental verification of reality. This concept lies at the heart of the scientific method, a deep understanding of which generates much more confidence in science and helps in the ability to differentiate legitimate from illegitimate claims both inside and outside of science.

An effective lab will be designed to illustrate and explore concepts from the other components of the coursework, better still if they also relate to the broader curriculum.

How do we introduce lab work to students? Start early. This example introduces laboratory work to 7th graders. While it is highly, and perhaps overly, procedural, it does introduce lab work. For example, I would not check the student data as soon as it was gathered, I would allow the students to continue on to the analysis and conclusion, and stress the questions of whether or not the conclusion is what they expected, and is the conclusion consistent with established science. Then follow up with the question of why, or why didn't, they expect the result. While this first example may serve as an introduction to more advanced lab work, it should be clearly understood as such an introduction by both the students and teachers. Can you see additional ways that this lab could be improved?

To many students, a laboratory activity has meant manipulating equipment but not manipulating ideas. Multiple studies confirm that the frequently observed ritualistic, even 'mindless' student behaviors observed in many laboratory activities stifle students' personal engagement in decision-making in the laboratory. These kinds of activities rarely uncover students' underlying beliefs; they do not encourage students to wrestle with their prior knowledge in making sense of their experiences, and they do not encourage them to reflect on their own thinking.³

Contrast the first example with another lab where once again middle school students tackle experimental work, but this time in an almost completely unstructured format. Here the students are confronted with a real world situation, their fish are dying due to a high pH, which would spike after a few days. When the teachers who had setup they system failed to find a cause, they involved their students in investigating the mystery. The students now know this is a real world investigation. According to the article, the students reached out to experts from UW-Milwaukee, who visited the school and worked with the students. This added more realism and helped the students follow accepted scientific methodology.

'With science, it's got to be hands-on, it's got to be real world,' said Stewart [one of the teachers]. 'Students did their own research for this, there's a sense of ownership for them.'

The real world nature of this lab will be hard to duplicate, but the successful involvement of eighth graders is promising and inspiring. Involving outside experts lends additional realism. Interestingly, the local cable company, Time Warner, has a program to connect practitioners with educational programs. Perhaps because it is new, there do not seem to be many programs visible in my geographic area.

Most students are best served by a path that touches on elements from both of these examples. For example provide a clear stage and goals for the lab as in the first example, while drawing the real world relevance and involvement of the students in designing the actual actions and analysis from the second.

The importance of hands on experience and dealing with errors and uncertainty in raw data speaks loudly to the superiority of actual experimentation over simulations of experimentations. Simulations can provide reinforcement of classroom material, and have a place in our instructional repertoire. However, they can not provide the confidence in science and the scientific method that flows from hands on experiments and direct observation. Fundamentally, simulations behave the way they do because that's how we built them. They are at least a layer or two of abstraction removed from actual physical reality.

• Learning in and from Science Laboratories: Enhancing Students' Meta-Cognition and Argumentation Skills. Avi Hofstein, Mira Kipnis, Per Kind, in Science Education Issues and Developments. 2008, Nova Science Publishers, Inc.
• The Role of Laboratory Work in School Science: Educators' and Students' Perspectives. Dr. Ali Khalfan Al-Naqbi, Dr. Hassan H. Tairab, Journal of Faculty of Education UAEU. Year 18, Issue No. 22, 2005.
• Learning and Teaching in the School Science Laboratory: An Analysis of Research, Theory, and Practice. Vincent N. Lunetta, Avi Hofstein, Michael P. Clough, Handbook of Research on Science Education, 2007, Lawrence Erlbaum Associates, Inc.
• The Role of the Laboratory in Science Teaching: Neglected Aspects of Research, Avi Hofstein, Vincent N. Lunetta, Review of Educational Research, Summer, 1982, Vol. 52, No. 2, Pp 201-217.
• Statistical Treatment of Experimental Data, Hugh D. Young, 1962, McGraw-Hill Book Company, Inc. Company.
• Beautiful Evidence, Edward R. Tufte, 2006, Graphics Pr.

Cross Cutting Concerns

The last entry talked about providing multiple illustrations of overriding themes within a subject. A closely related concept is providing views of the same or similar material, but when viewed through a different lens. In most cases the math, art, history and science curricula are developed in isolation. In reality there is significant overlap and meaningful interaction among these fields. Was Brunelleschi an artist, an architect, or an engineer? Was Leonardo da Vinci an artist or a scientist? Especially with da Vinci, how did these interests interact to produce a greater whole? In a more modern setting, Paul Graham's Hackers & Painters "points out that the similarities between hackers and painters are endless". James Burke's Connections has as a central theme of unexpected connections among technological advances, science, and economics. The Metropolitan Museum of Art even has a science department.

I have, for example, a strong memory of visiting the Fogg Museum at Harvard and seeing connections between studies and sketches to design patterns and iterative development development in computer software.

Remember that the recurring theme for this set of posts is making education more effective in the sense of making it more likely to be employed when encountering real world problems outside of the context of the classroom. Viewing material from multiple viewpoints is highly effective in this cause. Most directly, repetition is known to improve learning and recall of the subject matter. Presentation of material from multiple viewpoints and in multiple contexts increases both the ease with which it is incorporated into the student's existing knowledge base, and the depth of their understanding. It is important that the instruction emphasize that these are related presentations of the overarching theme. As always the students should be deeply involved in discussions about the relationships among the different contexts.

It is best if the repetition is separated in time. For example covering the development of the steam engine from an engineering perspective, then a couple of months later covering it from an economic perspective.

In addition to promoting both a deeper and broader understanding, this approach also strengthens motivation for understanding fields not obviously related to a student's central interests. A student interested in economics might ask why they should study physics. Now this style of teaching would show that economic concerns frequently set the tone for scientific progress, and that scientific progress frequently enables entire new economies. High speed communications enables corporations to be distributed over the entire planet, and brings many cultures closer together. Efficient transportation allows the distribution of manufacturing, and also the distribution of resources - especially in a time of crisis.

Another technique that I have had good success with is presenting the same abstract principle in significantly different contexts. It is important that the link between the examples and the general principle be explicit, understood by, and ideally discussed by the audience. The best results I have seen is when some of the audience provide the explanation themselves, perhaps with a little bit of coaching. This has additional benefits such as engaging the audience as an active participant in their own learning, and demonstrating to the audience that the material can be understood by their peers. This has been a subject of some interesting recent research^1,2 – indeed, reading this is what got me started writing about this topic. Relevance makes an appearance again – examples that are relevant to, or memorable for your audience are more effective.

In physics conservation principles such as the conservation of momentum and conservation of energy are stressed early with multiple examples from mechanics and electromagnetism. After four of five years these and other fundamental principles are ingrained into the learner's thought patterns.

Most disciplines lack such overarching principles so more effort is required to identify and incorporate abstractions into the learning process. Computer science, for example, has my favorite abstract principles, the concept of abstraction, and its child, the layered architecture. However, it is easy, perhaps even common, to focus to tools and algorithms while losing site of these important principles. To teach them in a way that is usable throughout the learners career requires that the abstractions be revisited with a clear discussion on how the principle manifests in each specific situation.

1) Analogical Encoding: Facilitating Knowledge Transfer and Integration, Proceedings of the twenty-sixth annual meeting of the cognitive science society
2) Learning and Transfer: A General Role for Analogical Encoding, Journal of Educational Psychology 2003, Vol. 95, No. 2, 393– 408

Putting knowledge – and education – to use.

This same principle has fascinating implications in the hiring process and in ethics.

People's ability to bring knowledge to bear on a problem as strongly dependent on the context of the problem. In software engineering I frequently raise an issue only to be countered with “I already know that”. Yes, but you are not employing that knowledge in your work. Knowing something about a topic, and indeed being able to discuss it fluently, is not the same as being able to employ that knowledge in a real world situation. Here, Joe Kraus, the founder of Excite, currently with Google Ventures, describes experts and "the mismatch between what they say is important, and what they actually do". This same phenomenon is commonly referred to in instruction as Transfer of Learning or Generalization. Understanding and addressing this is critical for effective instruction, instruction that can be employed out of the classroom in the real world, or even to disparate problems within the classroom that are manifestations of an underlying principle.

Of course I expect that many of you are saying "I already know that". But are you actively putting your knowledge to work? Are you measuring the effectiveness of your techniques?

What might some of those techniques be? Consider for example priming the pump – setting students into the frame of mind where they can see where the lessons will go, and how the material is relevant to the real world, especially their specific real world interests. Take a few minutes out of the last lesson of the week to give some pointers on what the next week will cover. Include comments guided by the known interests of the students. Yes – this means getting to know what drives your students. They will be thinking about the questions or applications from the preview all throughout your lessons. Also, cast the preview in a form that makes it clear that these goals are achievable by them. When I give a lecture I provide an abstract designed to get your attention and show the value of the talk. At the beginning I will provide an overview and touch on the relevance of the talk to your real world concerns. During the talk I will talk about applications, and if possible engage some of the audience members in a discussion about issues and applications important to them. I can remember when I was teaching and I employed these techniques then to good effect. OK, I admit I didn't generate any abstracts for my students.

More soon...