Why Hands-on Experiments Are Important
by Frank Eshelman, Ph. D.
We can learn science in many ways. Some examples are personal observations from everyday experiences, reading, watching videos or DVDs, listening to someone give a lesson and doing experiments. Here, we will examine some of the reasons that the study of science is important and why hands-on experiments are a necessary part of a good science course.
Ideally, science with hands-on experiments should be taught at every grade level. Studies have shown that students who have lab experience are much more likely to consider entering science fields such as medicine or engineering.
Lab experiments help students gain a better understanding of scientific concepts. Students learn that the study of science is more than just reading and memorizing facts. Experiments show that science includes discovery, learning new ways of thinking, and learning some new problem- solving methods. These skills are also important because they can be applied to many other subjects.
For example, let’s look at magnetism. You can learn about magnetism by reading about it, but you will understand it better if you also get a pair of bar magnets and experiment with them. Observe which poles attract each other and which poles repel each other. You can also float a piece of wood in a bowl of water, place a magnet on the wood and observe which direction the magnet “points”. As another experiment you could wind some wire around a large nail and connect the wire to a battery. (Be careful because the wire will probably get hot). Now observe the reaction between a bar magnet and the magnet you made by winding the wire on the nail.
Experiments at the elementary level are usually simpler than experiments at the high school level. Elementary level experiments will involve more examination and observation and less analysis, math or detail. Some examples are: Examining leaves or insects, using levers, making simple electrical circuits and watching simple chemical reactions.
Science at the high school level is more challenging and can seem abstract and unreal. Hands-on labs are necessary to help bring reality and understanding. Here, experiments are more involved and can be more expensive. For example, a microscope for biology study can cost more than $200. The labs will include more analysis, more gathering of data, and have longer, more complex procedures than at the elementary level. This material will often be at the college prep level and will help prepare students for college-level lab courses.
Many colleges require science lab courses at the high school level. Often these are courses such as general science, physical science, biology, chemistry, earth science, and/or physics. If a high school science course includes only material from books and DVD’s, a college may require an additional (and sometimes remedial) lab course to meet their requirements. For these reasons it would be wise for students to check out the entrance requirements for the college of their choice.
Because students enjoy lab experiments, they help them comprehend and remember science material. One teacher told me that when his students get bogged down and interest lags, he turns to experiments and the students “come alive”.
I teach a crash course in high school chemistry every fall. The material is covered very fast and students would not be able to grasp it if they didn’t have lots of labs (two lab experiments every day).
We can illustrate the importance of hands-on learning by looking at an experiment that I wrote for the manual in the “MicroPhySci Kit”, a comprehensive lab kit for middle school students. Here is a shortened version:
Atomic Motion and Diffusion
1. To become aware that atoms are in constant motion.
2. To observe diffusion through a liquid.
Atoms are in constant motion. In fact, at 250 C (770 F), the average speed of oxygen molecules is an amazing 1170 km/hr (1080 mi/hr)! This motion of atoms causes diffusion, which is the movement of one material through another material. We have all observed diffusion through a gas. Have you ever gone home and knew what you were having for dinner the moment you got there? The odor of the food had spread throughout the house by diffusion.
Materials and Equipment Needed
A Drinking glass, food coloring, water, and a source of heat (a stove).
1. Heat some water to boiling in a pan and fill the glass about ¾ full of this water. (Be careful, as the water is hot and can burn your fingers). The water will be about 1000 C (2120 F).
2. Put two drops of food coloring in the water near the edge of the glass.
3. Record the time it takes for diffusion to evenly distribute the coloring throughout the water.
4. Empty the glass (remember that it is hot) and fill it about ¾ full of luke warm water. Assume the water temperature is about 200 C (680 F).
5. Much like you did in Step 2, put two drops of food coloring near the edge of the glass and record the time it takes to evenly distribute the coloring throughout the water.
Results (See table above)
1. Record the temperatures and diffusion times in the table above.
2. If you take a trip in a car, what is the relation between the speed and the travel time?
3. If the diffusion time is shorter, is the diffusion rate faster or slower?
4. If the diffusion time is less when the water is hot, what can you say about the atomic motion?
5. What is the relation between the temperature and the atomic motion?
I hope that these suggestions have been helpful and will increase your interest in finding more hands-on science experiments.
Dr. Frank Eshelman is a retired engineering professor with 36 ½ years of teaching experience at both the high school and the college levels. He has a Ph.D. from Iowa State University in materials science and has been a consultant on many cases involving materials and/or produce failure. The chemistry kit he developed, the MicroChem Kit, has received several awards. He has also co-authored with Ken Schaefer, a former student, the manual for the MicroPhySci kit, a comprehensive lab science kit for middle school students. ■