SCIENTIFIC INQUIRY

Brainpop-Sci Method

How do you design an experiment?

• Your friend is always trying to make money. He says, “I think if we grow some flowers under red light, the flowers will be red and we can cell them for Valentine’s Day.”

• How could you design an experiment to test this idea?

A. Problem/Purpose• The question the lab

will answer

A. Problem/Purpose• Identifies the

independent and dependent variables

• Independent variable– The factor the scientist

changes

• Dependent variable– The factor the scientist

measures to see the effect of the independent variable

Fill it in …• IV: • DV:

B. Research/Background Information

• Lets the reader learn about the topic

• Helps the scientist develop an educated hypothesis

C. Hypothesis

• An educated prediction

• Can be tested, proven false, and agrees with research

• If __(IV)__, then __(DV)__

D. Procedure/Experiment

• Steps must be precise and detailed

D. Procedure/Experiment• Has at least one

control group – Normal conditions

or absence of independent variable

– Used for comparison

• Experimental group(s) have only one changing variable (the IV)

E. Observations/Data

• Must be objective– Good example:

The bacterial colony is yellow.

– Bad example: The bacterial colony is nasty

E. Observations/Data• Use measurements

whenever possible– Good example:

There are 50 bacterial colonies

– Bad example: There are a whole bunch of bacterial colonies

E. Observations/Data• Do not draw

conclusions in the data section of the report– Good example:

There are bacteria & fungal colonies in the shoe section

– Bad example: The shoe was really dirty and so it was the most contaminated and grew a lot of stuff

E. Observations/Data• Should be organized

– May use a graph, table, or drawing(s)

– Always include units of measurement and a title

F. Analysis/Conclusions

• Answers the purpose question

• Accepts or rejects the hypothesis

• Explains what can be inferred from the data

Fill it in …• Six Steps of the Scientific Method:

Sci Method Song

How do we know it is “good science”?

• Scientific knowledge must be shared, which allows other scientists to repeat and verify the work of others (peer review)

How do we know it is “good science”?

• Scientific knowledge is tentative– Theories are the most

logical explanation based on current evidence, become stronger as more evidence is gathered, and give us a basis for prediction

– Laws are universal generalizations that are virtually unchanging

• Theories explain, laws predict

Krabb Patty Power

Mr. Krabbs wants to make Bikini Bottoms a nicer place to live. He has created a new sauce that he thinks will reduce the production of body gas associated with eating crabby patties from the Krusty Krabb. He recruits 100 customers with a history of gas problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but is really just mixture of mayonnaise and food coloring. Both groups were told that they were getting the sauce that would reduce gas production. Two hours after eating the crabby patties, 30 customers in group A reported having fewer gas problems and 8 customers in group B reported having fewer gas problems.

1. Which people are in the control group?

2. What is the independent variable?

3. What is the dependent variable?

4. What should Mr. Krabbs’ conclusion be?

5. Why do you think 8 people in group B reported feeling better?

1. Mr. Mandarich wanted to see if the color of light shined on a plant had an effect on the number of leaves it had. He gathered a group of the same species of plants, gave them the same amount of water, and did the test for the same amount of time. Only the color of light was changed.

 Independent variable:  Dependent variable:  Constants: Control group (What would Mr. Mandarich use as a control group?): 

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis?• Which step is an educated prediction about

the outcome of the experiment?• In the experiment, “the effect of nicotine on

the heart rate of a cat?” …– The independent variable is ________________– The dependent variable is __________________– The control group would most likely be ________

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis? RESEARCH/BG INFO

• Which step is an educated prediction about the outcome of the experiment?

• In the experiment, “the effect of nicotine on the heart rate of a cat?” …– The independent variable is ________________– The dependent variable is __________________– The control group would most likely be ________

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis? RESEARCH/BG INFO

• Which step is an educated prediction about the outcome of the experiment? HYPOTHESIS

• In the experiment, “the effect of nicotine on the heart rate of a cat?” …– The independent variable is ________________– The dependent variable is __________________– The control group would most likely be ________

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis? RESEARCH/BG INFO

• Which step is an educated prediction about the outcome of the experiment? HYPOTHESIS

• In the experiment, “the effect of nicotine on the heart rate of a cat?” …– The independent variable is THE NICOTINE– The dependent variable is __________________– The control group would most likely be ________

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis? RESEARCH/BG INFO

• Which step is an educated prediction about the outcome of the experiment? HYPOTHESIS

• In the experiment, “the effect of nicotine on the heart rate of a cat?” …– The independent variable is THE NICOTINE– The dependent variable is THE HEART RATE– The control group would most likely be ________

Check Yourself!• Which step of the scientific method is used to

develop a hypothesis? RESEARCH/BG INFO

• Which step is an educated prediction about the outcome of the experiment? HYPOTHESIS

• In the experiment, “the effect of nicotine on the heart rate of a cat?” …– The independent variable is THE NICOTINE– The dependent variable is THE HEART RATE– The control group would most likely be CAT(S)

WITH NO NICOTINE