1. Designing an Experiment
Unit 1
Designing an Experiment

2. (1) State the Question What do you want to know? (Problem)
What is the effect of ________________
on ________________?
Independent variable
Dependent variable

3. Problem
Which brand of microwave popcorn pops the most kernels per bag?
IV/MV: Brands of popcorn
DV/RV: Number of kernels that popped

4. (2) Make a hypothesis A prediction of the experiment’s outcome
Written as an “If…then…” statement.
If IV/MV is action Then DV/RV is action
Example:
Hypothesis: IF 4 different brands of popcorn are popped, THEN Movie Time popcorn will pop Prediction Prediction
the most kernels per bag

5. (3) Design the experiment
Materials – list of things you need to perform the experiment
Procedure – Numbered list of steps you take to perform the experiment

6. Design the Experiment Materials List 4 brands of microwave popcorn
Bowl
Data table
Procedure
Buy 4 different brands of microwave popcorn
Pop 1st bag of popcorn
Count number of kernels popped
Record Data into data table

7. (4) Make observations Record data
Use appropriate metric units as needed
Ex: Record Data into data table
Brands
Trial 1
Trial 2
Trial 3
Average
Store Brand
234
236
225
232
Orville Reden
330
335
328
331
Movie Time
285
278
281
Jiffy Pop
258
250
248
252

8. (5) Study results Shown as graphs – make graph from data table
1. Bar Graph
2. Line Graph
3. Pie Chart

9. (6)
conclusion
Describes the purpose and the results of the experiment.
3 steps to the conclusion
Ex:
1 Answer the ? asked in the problem
2. Restate hypothesis and state if it is correct or incorrect
3. Use the data from data table to support your conclusion

10. Conclusion
The brand of microwave popcorn that popped the most kernels per bag was Orville Redenbacher. The hypothesis was incorrect. It stated that Movie Time brand would pop the most kernels per bag, but the data table showed that Orville Redenbacher popped 331 kernels and Movie Time popped 281 kernels.

11. Parts of an Experiment

12. (8) control Used as a comparison Unchanged/Natural/Original
Ex: The store brand of microwave popcorn

13. Experimental Group The group that is changed or tested
Ex: The 3 national brands of microwave popcorn

14. (7) Independent variable I change the independent variable.
Also called the manipulated variable
Each experiment should only test ONE I.V. (MV)
Ex: The 4 different brands of microwave popcorn

15. = = Independent variable Changing the brands of Microwave popcorn
Changing One variable
Changing the brands of popcorn and the time it cooks =
Changing too many variables

16. (9) Dependent variable This is what the IV (MV) effects.
This is what you measure/collect data from
Ex: The number of kernels that popped

17. (10) constants Factors that stay the same in an experiment.
There are MANY in an experiment.
Examples:
Same microwave
Same amount of popcorn per bag by weight
Cook for the same amount of time

18. (11) trials More trials = More reliable results.
Ex: pop 3 bags of each brand to ensure more reliable results