Designing an Experiment

SCIENTIFIC

INQUIRY

Designing an Experiment

• Designing an experiments starts with what?

Observation!

What’s an observation? What do we use to make them? We use our Five Senses to make an observation!

• Then a question regarding that observation is asked.

The PROBLEM QUESTION

The PROBLEM QUESTION…

• Before you ask this question you must

know what VARIABLES you are working

with.

• Every experiment has two variables:

INDEPENDENT

and

INDEPENDENT VARIABLE

• This is the variable that you will be

controlling (changing) in the experiment.

DEPENDENT VARIABLE

• This is what you will be measuring in the

experiment.

• This is the variable that gives you the

data you will be collecting.

Airplane Lab

• Each cadet will make their own paper

airplane

• Then, each will take turns throwing their

paper airplane only once

• Next, each cadet will make one

modification to their airplane

• Who has the closest birthday to today?

That cadet can make as many

Airplane Lab

• Now throw a second time from the same

spot as the first time

• How did your modification cause your

airplane to fly differently?

• If you made many modifications which

ONE modification caused your airplane to

fly differently?

Airplane Lab

• In the airplane exercise we just did, what

was the I.V. and D.V.?

• I.V.= the different modifications you made

to the plane.

Because you controlled what changes to

make.

• D.V. = Distance the plane traveled.

Let’s Practice…

Pepper Lab

You want to grow some big peppers this summer, but you do not know which

fertilizer will make them grow biggest. Last year you didn’t use any fertilizers, so this year you set up five rows of peppers. Here is what you put on each row:

Let’s Practice…

Pepper Lab

You want to grow some big peppers this

summer, but you do not know which

fertilizer will make them grow biggest.

Last year you didn’t use any fertilizers,

so this year you set up five rows of

peppers.

QUESTION:

ANSWER…

• I.V. = type of fertilizer

Because it is what we are

controlling/changing.

Let’s Practice Some

More…

Tea Lab

You want to know if sugar will dissolve

faster in cold or hot tea.

QUESTION:

ANSWER…

• I.V. = temperature of the tea

Because it is what we are

controlling/changing.

• D.V. = time it takes the sugar to

dissolve.

Setting Up a Data

Tables

When you make a data table:

• the I.V. always goes on the LEFT

• the D.V. always goes on the RIGHT

1 2 3 4

The PROBLEM QUESTION…

• Now that you know what variables are,

you can write the problem question for

the experiment!!!

• Follow this formula:

What is the effect of the _________

Let’s Practice…

Airplane Lab

Write the problem question for the Airplane Lab.

ANSWER:

What is the effect of the different types of

Let’s Practice…

Pepper Lab

Write the problem question for the

pepper experiment.

ANSWER:

What is the effect of the type of

Let’s Practice Some More…

Tea Lab

Write the problem question for the hot

and cold tea experiment.

ANSWER:

Designing an Experiment

• Starts with an observation.

• Then a question regarding that

observation is asked.

The PROBLEM QUESTION

• From there you must figure out a way to

collect data that will help answer your

Designing an Experiment

• Next, you think about what you expect the outcome to be.

This is done BEFORE the experiment and is based on your prior knowledge of the

situation. (NOT a guess!!!)

The HYPOTHESIS:

An “Educated Prediction” not a guess!

The HYPOTHESIS…

Follow this formula:

If _________________________

Then the ___________

Let’s Practice Together…

Write a hypothesis for the Airplane

experiment using the “variable” you

chose!

ANSWER:

Let’s Practice…

Write a hypothesis for the pepper

experiment.

ANSWER:

IF the type of fertilizer is cow poop

Let’s Practice Some More…

Write a hypothesis for the hot and cold

tea experiment.

ANSWER:

If the temperature of the tea increases

Then the time it takes the sugar to

Warm-up

You want to know if you will perform

better on a science exam if you study

for 30 minutes a night instead of the

usual 60 minutes.

• Write the

I.V

. &

D.V

.

• Problem question

• Hypothesis

for the following scenario.

Answers

• I.V. =

the time you study each night

• D.V.

How well you perform on the exams

• What is the effect of the time I study

for my science exam on how well I

perform on the science exam?

• If I study 30 minutes a night for my

Designing an Experiment

Now you know how to:

• Make an Observation

• Determine the I.V. and the D.V.

• Write a Problem Question

• Write a Hypothesis

Constants and Controls

• In every experiment you can only change one variable. The rest must be held constant.

• A constant is something that stays the same throughout the lab.

• What was the constant in the Airplane Lab?

• Where you stood during your throw!

• 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)

What was the control in the Airplane Lab?

The

CONTROL GROUP…

• You will collect data from this group,

BUT it does not have any of the I.V.

Challenge…

What is the control group in the

Pepper experiment???

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}

Answers…

• I.V. which group gets the special juice

• D.V. how many stacks of papers each

group has made.

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 Variable}

Answers…

• I.V. which side of the shower was

sprayed with what substance.

• D.V. the appearance of the green slime

in the shower

Identifying Controls and Variables

Bart 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}

Answers…

• I.V. Which mice were microwaved or not.

• D.V. If they could move the heavy wood

block or not.

Experimental

Design

Your Mission…

For each of the following experiments write

:

1. The independent variable

2. The dependant variable

3. A problem question

Breakfast Experiment #1

A study is being conducted to find out if

students who eat a healthy breakfast

before school perform better

academically.

One group of students is given no

Breakfast Experiment #1

1. The independent variable- The different types of breakfast consumed

2. The dependant variable- test scores

3. A problem question/statement- What is the effect of the different types of breakfast consumed by students on their test scores?

4. A hypothesis- If a student eats a healthy

breakfast then their test scores will increase.

Air Freshener Experiment #2

I see a commercial on T.V. that claims

this product removes Jon’s bad odors

better than any other. I decide to try

the product and see if it really works on

Jon’s bad odors. For the first week I

used

Febreeze

on Jon, for the second I

use

Stink-B-Gone

on Jon, for the third

week I used

Why-B-Stinkin’

on Jon and

for the fourth week, unfortunately I

The Air Freshener Experiment #2

air freshener

2. The dependant 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.

Flashback Questions

• 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 so important in a lab?

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 FOUR items…

1. The PURPOSE of the experiment 2. The HYPOTHESIS

3. What the data showed (results statement)

Use at least 2 examples of Data (numbers) to support the results statement.

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 Data

My Hypothesis: If I use cow poop, then the size of the peppers will increase.

Type of fertilizer (I.V)

Cow poop

Miracle Grow

Nitrogen

Nothing

Compost

Size of Peppers (D.V.)

4 inches

1 inch

2 inches

3 inches

8 inches

Pepper Conclusion

Example

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 the size of the peppers will increase.

3. The data showed that as I used cow poop, the peppers increased from 3 inches with no

fertilizer to 4 inches in size.

Breakfast Lab

Type of Breakfast Test Scores

No Breakfast

Junk Food

Healthy breakfast

Write a conclusion for the Breakfast Lab using this data.

I.V. types of breakfast D.V. test scores

72%

84.3%

Breakfast Conclusion

The purpose of this experiment was to

determine the effect of the different

types of breakfasts on the test scores.

My hypothesis was that if I eat a healthy

breakfast then my test scores will

increase.

The data showed that with no

breakfast the test scores averaged a

72%, but with a healthy breakfast test

scores averaged a 94.5%.

The data did

Air freshener Lab

Type of Air Freshener

Febreeze

Stink-B-Gone

Why-B-Stinkin’

Nothing

Write a conclusion for the air freshener Lab using this data.

I.V. types of air fresheners D.V. days he smelled good

Days he smelled good

Air freshener Conclusion

The purpose of this experiment was to

find the effect of the different types

of air fresheners on the amount of days

he smelled good.

My hypothesis was that if I use

frebreeze on him then his stink would

decrease.

The data showed that with no air

freshener he smelled good zero days,

but with frebreeze he smelled good for

four days.

Flatulence Experiment

Mr. Miller and Mr. Bais 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….

*

Homework

Every conclusion needs to have the following FIVE items…

1. The PURPOSE of the experiment

2. 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

The Data

Was your hypothesis correct?

Types of Food

No Food

Baked Beans

Broccoli

Cabbage

Amount of Flatulence

13 Flatulence

41 Flatulence

34 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.

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 with no food the

amount of Flatulence was 13, but with the use of baked beans the Flatulence increased to 41.

Flavored Dog Bone Experiment

Fish 15 minutes

Beef 25 minutes

Liver 2 minutes

Chicken 5 minutes

Lamb 12minutes

Original Bone 10 minutes

So that I am not wasting money, I want to find out what kind of flavored

bone is my dog’s favorite. I buy five different

flavored bones (chicken, beef, liver, fish, and lamb) and leave out her original rawhide bone; then I keep track of the amount of

Flavored Dog Bone Answers

flavored dog bones

2. The dependant variable- amount of time the dog spends with the flavored bone

3. A problem question- What is the effect of the different types of flavored dog bones on the amount of time the dog spends with the

flavored bone?

4. A hypothesis- If the dog is given a beef

flavored bone then the amount of time the dog spends with the bone will increase.

*Flavored Dog Bone Experiment

The purpose of this experiment was to find out the effect of different flavors of bones on the time the dog spends with the bone.

My hypothesis was if the bone is beef

flavored, the amount of time the dog spends with the bone will increase. The dog spent 25 minutes with the beef flavored bone,

compared to the 10 minutes the dog spent

with the original bone. The data did support

CaCl

₂

Experiment Conclusion

The purpose of this experiment was to find out the effect of different amounts of CaCl₂ on the temperature of the water. My

hypothesis was if the amount of Cacl₂ is

increased then the temperature of the water will increase. The data showed that the

temperature did increase. At 0 scoops of CaCl₂ the temperature was 20.4o Celsius.

When I added one scoop it was 21.2o, 2 scoops 22.3o and the temperature continued to