Experimental Designer Scenarios

CHECK YOUR HOMEWORK FIRST…

Identifying Controls and Variables

Smithers thinks that a special juice will increase the productivity of workers. He creates two groups of 50 workers each and assigns each group the same task (in this case, they're supposed to staple a set of papers). Group A is given the special juice to drink while they work. Group B is not given the special juice. After an hour, Smithers counts how many stacks of papers each group has made. Group A made 1,587 stacks, Group B made 2,113 stacks.

1. Independent Variable

2. Dependent Variable 3. Control Group

Answers…• I.V. which group gets the special juice• D.V. how many stacks of papers each

group has made.• Control is Group B because the did

not get the special juice. We can compare the results to this group!

Identifying Controls and Variables

Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water as always. After 3 days of "treatment" there is no change in the appearance of the green slime on either side of the shower.1. Independent

Variable2. Dependent Variable3. Control Group

Answers…• I.V. which side of the shower was

sprayed with what substance.• D.V. the appearance of the green

slime in the shower• Control the side of the shower that

was sprayed with water.

Identifying Controls and VariablesBart believes that mice exposed to

microwaves will become extra strong (maybe he's been reading too much Radioactive Man). He decides to perform this experiment by placing 10 mice in a microwave for 10 seconds. He compared these 10 mice to another 10 mice that had not been exposed. His test consisted of a heavy block of wood that blocked the mouse food. he found that 8 out of 10 of the microwaved mice were able to push the block away. 7 out of 10 of the non-microwaved mice were able to do the same.

1. Independent Variable

2. Dependent Variable3. Control Group

Answers…• I.V. Which mice were microwaved or

not.• D.V If they could move the heavy wood

block or not.• Control The mice that were non-

microwaved.

Experimental Design

Mission

Your mission…For each of the following experiments

write:

1. The independent variable2. The dependent variable3. A problem question/statement4. A hypothesis 5. Control group

Experiment #3 While baking cookies I notice that the

bottom of my cookies are burning and the tops of the cookies are still mushy. I want to see if changing the type of cooking pan will make my cookies come out better.

For one batch I use the same pan as always, for the second I use one that is nonstick, and for the third I line it with aluminum foil.

Cookies1. The independent variable- Different types

of cookie pans2. The dependent variable- the taste and form

of the cookies3. A problem question/statement- What is the

effect of the different types of cookie pans on the taste and form of the cookies?

4. A hypothesis- If the pan lined with aluminum foil is used then the taste and form of the cookies will increase in satisfaction.

5. Control group- The original pan

Warm up Question• What is the difference between a control and

a constant?• A constant is something that stays the same

throughout the lab.• The control group is the part of the lab that

we use to compare our results to! No changes are made to the control in the lab! (Usually the original)

• Why is the control important in a lab?• It allows us to compare the variables in the

lab!

Air Freshener Experiment #4

I see a commercial on T.V. that claims this product removes bad odors better than any other. I decide to try the product and see if it really works on bad odors. For the first week I use Febreeze, for the second I use Oust, for the third week I use Glade plug-in and for the fourth week, unfortunately I use nothing.

The Stink- Eliminator Experiment

1. The independent variable- Different types of air freshener

2. The dependent variable- the amount of odor removed

3. A problem question/statement- What is the effect of the different types of air freshener on the amount of odor removed?

4. A hypothesis- If the air freshener used is Febreeze then the amount of odor removed will increase.

5. Control group- No air freshener

Warm up Question• What is the difference between a

control and a constant?• Please give an example of each from

the different labs we did in class. (Airplane, pepper, dog bones, baking pans)

Writing a conclusion to an experiment…

A conclusion is how you will share the overall results of your experiment. Every conclusion needs to have the following FIVE items…

1. The PURPOSE of the experiment2. The HYPOTHESIS 3. What the data showed (results

statement)4. Data (numbers) to support the results

statement. (use at least 3 examples)5. If the data supported, did not support, or

was not clear about the hypothesis.

Writing a PURPOSE…

Use the formula:

The purpose of the experiment was to determine the effect of the (I.V.) on the (D.V.).

Pepper Lab DataType of fertilizer (I.V) Size of Peppers (D.V.)Cow poop 4 inches

Miracle Grow 1 inch

Nitrogen 2 inches

Nothing 6 inches

Compost 5inches

Pepper Conclusion Example

Title-The Pepper Experiment• 1. The purpose of the experiment was to

determine the effects of the different fertilizers on the size of the peppers.

• 2. My hypothesis was if I use cow poop, then my peppers will increase in size.

• 3. The data showed that although cow poop perppers did grow the group with nothing grew more.

• 4. The data showed that with cow poop the peppers grew to 4 inches but with nothing they grew to 6 inches. Cow poop peppers did grow more than the group with miracle grow to 1 inch.

• 5. The data did NOT support my hypothesis.

Flatulence Experiment

The crazy science department wanted to see what types of food would make them the most gassy. First they tried bake beans. The next day they tried broccoli. The following day they tried cabbage. They also took data without eating any food.

YOUR MISSION…..For each of the following experiments

write:

1. The independent variable2. The dependent variable3. A problem question4. A hypothesis 5. Control group

The Data(copy this down)

Types of Food

Amount of Flatulence

No Food 13 Flatulence

Baked Beans 41 Flatulence

Broccoli 34 Flatulence

Cabbage 26 Flatulence

Flatulence Experiment

• IV- The type of food eaten• DV- The amount of Flatulence • Problem Question- What is the effect

of the type of food eaten on the amount of Flatulence ?

• Hypothesis- If the type of food eaten is baked beans then the amount of Flatulence will increase.

• Control Group- No food

YOUR MISSION….Write the conclusion for the Flatulence experiment.

Every conclusion needs to have the following FIVE items…

1. The PURPOSE of the experiment2. The HYPOTHESIS 3. What the data showed (results statement)4. Data (numbers) to support the results

statement.Remember to use two examples. Maximum and

minimum.5. If the data supported, did not support, or

was not clear about the hypothesis.

Flatulence Experiment Conclusion

The purpose of this experiment was to find the effect of the different types of food eaten on the amount of Flatulence produced. The hypothesis was that if the food eaten was baked beans that the amount of Flatulence produced would increase. The data showed that any food increased the amount of farts.The data showed that with no food the amount of Flatulence was 13, but with the use of baked beans the Flatulence increased to 41. There was an increase of 28 Flatulence . The data supported the hypothesis.