EKF :: Ku’ula 7-9 Curriculum

Phase 4 : Experimental Design

As stated in the science fair overview, the teacher plays the role of facilitator in this project. More than any other phase of the project, students will try to get you to do their experimental design for them. Students have become so used to being spoon fed all of their information, they've come to expect it from their teachers all the time. This science fair project works to kick that habit and have students really think and decide for themselves.

To design their experiment, students must first have a solid hypothesis. The hypothesis should give them some hints as to how they need to design their experiment. As a teacher you need to provide them with the basic information to get them started and then let them go. This is a genuine trial-and-error procedure, so be sure to reserve a lot of time for students to complete this phase. Students will struggle through a first draft of their procedures and turn it in to you for feedback. Here is where you can assist them but be careful not to tell them how to do their experiment. When checking their procedures, point out procedures that probably won't work but let them figure out how to fix them. Let them know if they are way off track, but let them figure out how to get their experiment back on track. Again we want the students to gain a sense of ownership for this project. They will not get that if we spoon feed them everything.

Experimental Design Notes

The Beef Stew Analogy

To emphasize the importance of detailed materials list and procedures you can use the beef stew analogy. This will also help them see that the procedures often dictate the materials list and that you often have to go back and forth between the two to make revisions. This can be done as an entire class or in small groups.

After going over the experimental design notes, tell the class that they will be cooking beef stew as a class project. Ask if anyone has cooked beef stew or anything else before. Then ask the class to come up with a shopping list of ingredients to make the stew. The shopping list will most likely be vague. They may list potatoes without giving the amount or the type of potato, etc. Just let them go for the moment. Give that shopping list to someone on the class who has no shopping experience. As a class walk through the shopping process by having the students visualize following the student while he/she shops. Take them to the produce section and have the student tell you what he/she would buy. Don't let the class correct that student's choices. After the student chooses the produce items, you can point out the missing details in the shopping list. Then it's on to the next section of the grocery store. They'll be a lot of laughs but they will start to see the point.

Once you've gone through the shopping list (materials list) ask them to come up with a recipe (the procedure). The recipe will probably have missing details as the shopping list did. Once the students finish the recipe, find someone in the class who has no experience in cooking. Give that person the recipe and have them pretend to cook the stew. You can use classroom materials as substitutes for the ingredients. Again, let the student cook get through a few steps of the recipe without any corrections from the class. After a few steps, then start to point out the missing details. For example, one of the first steps of the recipe may be to chop up the potatoes but it will not say to wash and peel them first. Again students will start to see your point.

After going through the beef stew analogy, take it back to their science fair experimental design to again show them the connections. Emphasize how procedures have to come first; how do you know what needs to go on your shopping list without a recipe? Re-emphasize the importance of detail. Both the materials list and the procedures should be clear and detailed enough for other people to duplicate the experiment. Now you are ready to go over the experimental design requirements with the students.

Experimental Design Score Sheet

Students should go through at least 2 experimental design drafts before turning in a final draft. The first draft should be assessed by the teacher to catch any initial mistakes and to provide the student with feedback. You also want to check for any safety red flags or considerations that the students may have missed. If possible, meet with students individually to go over their procedures. The next draft can be assessed by their peers.

Experimental Design Peer Evaluation

Again check to make sure that the students are following the timeline and are not falling behind during this phase. It is essential that the students have a solid experimental design before starting their experiment. If their experimental design is flawed, so will their data.