U1C1A4 Evaluating Experimental Design

Exp 1: Heating Earth Materials 1Q: If the type of Earth’s material is changed, what happens to the temperature of the material as it is heated by sunlight?

2. MV: type of Earth materials RV: temperature of Earth materials as heated by sunlight

3. MV values: twp types of Earth materials - dirt and water

4. RV is measured in temperature, Degrees C, with a thermometer

5. Same: buckets, amount of sunlight, thermometers and their placement, time in the sun

6. Differences other than MV and RV: Yes, the amount of Earth material Full bucket soil, 1/2 bucket water

7. No, this is not a fair test - more than one variable - see answer to #6. (amount of Earth material varies)

Exp 2: Freezing Water 1Q: If hot and cold water are placed in a freezer, which freezes more quickly?

2. MV: water temperature RV: time it takes for water to freeze

3. MV values: tray of hot water, tray of cold water

4. RV measured by time intervals, and observing if water frozen

5. Same/control: tray size amount of water added in each tray liquid used is water 15 minute interval checks both put in the same freezer

6. Different other than MV and RV: Yes. The trays are made out of different material (metal, plastic), and they are place on different shelves in the freezer (top, bottom)

7. This experiment is NOT a fair test because of #6, more than one variable (tray material and location).

Exp 3: Corn 1Q: If the type of corn seed is changed, what happens to its growth rate and health in crowded conditions?

2. MV: type of corn seed RV: growth rate and health

3. MV value: seed types 1,2,3,4

4. RV measured by observation of the plant health, and measurement/count of growth

5. Same/control: same number of seeds in each pot, same pot sizes same depth planted same amount of water all checked at same time (3 weeks)

6. Different other than MV and RV: Yes, the type of soil in each pot is different

7. No this is not a fair experiment, because there is more than 1 variable (soil type)

Conclusion: You should be able to answer/identify the 7 criteria used in this activity to determine if an experiment is designed fairly: 1Q 2: MV, RV 3: values MV 4. RV measurement 5. Same controls 6. Different variables 7. Answer (Fair, yes or no)

Share/Communicate: See the “How to Analyze an Experimental Design and determine if the Experiment is a Fair test”