K-BLOG 8: Freedom to Design an Experiment: Reaction Time Lab
The Challenge:
For most of my school life and at least half of my teaching career, students participated in what are sometimes called, “Know the Outcome Science Experiences”. These were the type of “experiments” that had been done by countless generations of students. Some examples of these are: conducting chemical tests to see if something is a sugar or protein, noting the effect of a variable such as acid on seed germination, or observing the reaction of hydrogen peroxide on liver. It’s not that these “experiments” did not teach something to the observer. It’s that the student participant was not free to explore. They were usually given a set of instructions to follow, and even a pre-made data chart to fill in. It should be a given that your class has the opportunity to explore phenomena, collect data, and design and improve their own experiments. Even though many educators have changed their approach to teaching the “doing” of science, it is sometimes tough for teachers to give up control to their students. It is especially important to allow kids to experience and learn from experiments that do not work. Students must be given the confidence to believe that their mistakes and misleading ideas are valued. When students have an idea for an experiment and they defend the idea through a logical experimental design, if safe, they should get the go ahead to try their self-designed experiment. When I have students design one of their first experiments, I like to give them some broad parameters so that equipment and costs do not to not bog them down.
A Solution:
My goals are for students to think about how to design experiments, have fun, and not be afraid to do what they want to do, as long as it is safe. They should not have the idea that there is only one right way to design an experiment. In my reaction time experiment, for example, I start off by saying, “Create an experiment using a reaction time test to study something about reaction time”. What should they do? The students work together and brainstorm to produce some parameters. The expectation is that they must develop a well-defined testable question that they can explore using a computer or any type of reaction test. Students should develop an experimental plan that includes: 1) a research question; 2) experimental variable; 3) control variable; 4) constants. Here are some of my students' ideas:
Reaction Time: Athletes vs. Non-Athletes
The Effect of Music on Visual Reaction Time in High School Students
How does Shape/Color Affect Visual Reaction Time?
Reaction Time to Sound Cues of Musicians vs. Non-Musicians
Resources:
Some online computer reaction time tests
Red Light – Green Light Reaction Time Test
https://faculty.washington.edu/chudler/java/redgreen.html
Auditory Reaction Time Test
https://new.cognitivefun.net/task/cogfun-16-auditory-reaction-time
Reaction Timer – respond to an image on a computer and get reaction times. It is possible to vary the way the image is presented on the screen.
https://nrich.maths.org/reactiontimer
Ruler Reaction Time Test
https://www.crick.ac.uk/whats-on/public-events/family-zone/test-your-reactions
