Name ________________________                                                       Date __________

Review Sheet: Experimental Design and Scientific Method

Experimental Design

A. Scientific Method (Remember with “QHEIC” or “Quickly Heather Eats Ice Cream”)

1. Question – 1^st step of Scientific Method – Be able to write a question that can be explored with an experiment
2. Hypothesis – Be able to write in If-then-because format
3. Experiment – Be able to design and conduct experiments
4. Interpret Data – Be able to design and interpret charts, tables, and graphs
5. Conclusion – Make a conclusion based on your hypothesis and the results of your experiment

B. Sources of Error: Be able to identify sources of error and evaluate your hypothesis based on experimental results

C. Types of Variables and Key Vocabulary

1. Independent Variable = Manipulated Variable = the variable you purposely change (remember with “IM purposely changing”)
2. Dependent Variable = Responding Variable = the factor that may change as a result of the manipulated variable (remember with “the DR is expected”)
3. Experimental Group = the setup whose conditions you manipulate during an experiment
4. Control Group = the Control = the setup with ‘normal’ conditions; conditions are NOT being changed; this group is used for comparison
5. Controlled Experiment = a properly done experiment which keeps all conditions the same for the experimental and control group, except for the manipulated variable
6. Constants = conditions that are kept the same in the experimental and control group so you have a controlled experiment

Deena Bollinger                                                                                                                                   Grade 8 Science teacher

STANYS Westchester Section                                                                                               South Orangetown Middle School

Middle Level Subject Area Representative (SAR)                                                                                                  Blauvelt, NY

Name _______________________________                                       Date __________

Question and Hypothesis Worksheet

A student is interested in designing several experiments to test the factors that effect how quickly an Alka-Seltzer tablet dissolves in water (solution rate).  For each question, write a hypothesis that could be tested with an experiment.  Be sure each hypothesis is in the proper “If…then…because…” format.  See example below.

Example:

Question: What effect does stirring have on solution rate?

Hypothesis: If the water is stirred, then the tablet will dissolve faster because stirring increases solution rate.

1. Question: What effect does the water temperature have on solution rate?

Hypothesis: ___________________________________________________

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2. Question: What effect does crushing the tablet have on solution rate?

Hypothesis: ___________________________________________________

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3. Question: What effect does adding soda to the water have on solution rate?

Hypothesis: ___________________________________________________

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The next few questions are about factors effecting plant growth.  Write a hypothesis for each question using the proper “If…then…because…” format.  See example above.

4. Question: What effect does amount of light have on plant growth?

Hypothesis: ___________________________________________________

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5. Question: What effect does amount of water have on plant growth?

Hypothesis: ___________________________________________________

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6. Question: What effect does using plant food (Miracle Grow) have on plant growth?

Hypothesis: ___________________________________________________

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Name _______________________________                                       Date __________

Experimental Design Exercise

Choose one of the factors that effect how quickly an Alka-Seltzer tablet dissolves in water (solution rate).  You will now follow the scientific method to determine if your hypothesis is correct.  Use this sheet to plan your experiment and collect your data.

Question: Write the question you are trying to answer (see Question and Hypothesis Worksheet).

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Hypothesis: Write your hypothesis using the proper “If…then…because…” format (See Question and Hypothesis Worksheet).

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Experiment: Plan your experiment by following the steps below.

What is your manipulated variable (AKA independent variable AKA what you are testing)? _________________________

What is your responding variable (AKA dependent variable AKA what you are expecting will change)? ______________________

What variables must be kept constant for this to be a controlled experiment?

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List ALL materials you will need to perform your experiment.

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List the steps you will follow to perform your experiment.  Don’t forget about the control group, and don’t forget to repeat the experiment!

1. _____________________________________________________________

2. _____________________________________________________________

3. _____________________________________________________________

4. _____________________________________________________________

5. _____________________________________________________________

6. _____________________________________________________________

Collect your data here – Complete the data table during your experiment.

Interpret Data: What does your data show?  Be specific and descriptive.

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Conclusion: Based on your experiment, is your hypothesis true?  If it is true, restate your hypothesis below, if not true then revise your hypothesis below.

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Do you want to try another experiment?  If so, describe what you would like to do?