It is time-consuming and exhausting, but well worth the effort!
The bottom line here is that students must learn to write and carry out an experiment of their own design. Major problem: A truly well designed experiment takes time. It takes time for the teacher to teach the student "HOW" to design the experiment, it takes a lot of time for the student to actually design the experiment, and then it takes more time for the student to carry out the experiment.
I think this is an important skill and well worth the effort. But if you decide to go this route with your students, be prepared for the fact that it will take much preparation and teaching on your part.
Okay, so where do you start? The first step is to make sure that the student is well-grounded in the scientific method. This means the student has to be able to do more than write down the steps to the scientific method. They have to be able to APPLY the scientific method to a problem or a question.
I can help with that. I have a PowerPoint, complete with notes for the teacher and the student, that teaches the application of the scientific method. Click this link: Scientific Method PowerPoint and Notes.
The next step is to have the students practice writing a lab procedure. I love this activity: Give the students some building materials. They can be old legos, tinker toys, paper clips, styrofoam peanuts. Any type of items will do. Each student takes their building materials and builds some sort of structure or device. They then have to describe, in writing, how to build their device. The students swap written descriptions and try to build their lab partners device from the written description. Click this link: Can You Write A Lab Procedure.
Now it is time for the student to design their own experiment from beginning to end. Start with something simple....something VERY simple. For our first effort, I had my students design an experiment to test the effect of different quantities of water on the germination of radish seeds. Simple , right? It turned out to be such a great idea! There are limited options for the students and no advanced knowledge about the topic was needed.
Radishes were a great choice! They germinated within 24 hours, and I allowed my students to observe their germination rate every day for three days. I had my students complete a lab report in which they had to design and complete the following:
- State a hypothesis that is testable.
- Write out detailed steps to their procedure.
- Determine the independent and the dependent variables.
- Include a description of their control and how it served as a control.
- Include a description of their experimental groups.
- Identify factors that must remain constant throughout the experiment.
- Design a data table.
- Graph their germination rates.
- Form a conclusion based on the data gathered.
Below are a few pictures that I took during the lab activity:
Our science students need to develop this skill. Take the time in your class to teach experimental design. It is well worth the effort!
Here are the links to the radish seed experiment as well as a few other labs I do in which the student must design their own experiment.