Scientific Method

Ms. Yanuck’s Class

Scientific Method

• Systematic way scientists solve

problems or answer questions.

• Series of steps designed to test a

hypothesis.

Scientific Method Steps

Step 1: make observations which lead you to

ask a question or identify a problem.

Step 2: form a hypothesis about the solution

to the problem (if…then…because

statement).

Step 3: test the hypothesis with an experiment.

Step 4: data collection and organization

Step 5: make a conclusion (is your hypothesis

correct?)

Step 6: share your results

Scientific Method

Observations

Two types of Observations

1. Qualitative observations are made

using our five senses. (touch, taste, smell,

sight, hearing)

– Ex. “There is ice on the roof”

2. Quantitative observations are made

using numbers and measurement (you

can ask “how much?” or “how many?”.

– Ex. “The mass is six grams”

Observations should

be precise

• Good Observation:

“The mold was green and 5 cm long”

• Bad Observation:

“There was a lot of icky green mold”

• A hypothesis is an educated guess based

on observations that leads us to create an

experiment.

• A hypothesis is written as an

“if….then….because” statement.

• “If” explains what you, the scientist, will do.

• “Then” explains what you guess will

happen.

• “Because” explains why you think it will

happen.

Example: If Ms. Yanuck gives a test on

Friday, then the students will get a good

grade because they studied on Thursday.

• The independent variable is the thing

(condition) that the scientist controls or

changes on purpose.

The “if” part of a hypothesis.

• The dependent variable is what happens

in the experiment due to the change.

The “then” part of the hypothesis.

Experiment

• Control – part of the experiment you

do nothing to and do not change

• Constant – Everything except your

variable stays exactly the same.

• Trial – You need to test it more than

once

Data Collection and

Graphing

Data Collection and Graphs

• Data is information collected from the

experiment

• Data is used to analyze the results of an

experiment and draw a conclusion about

whether the hypothesis was proven to

be right.

• Data can be presented as graphs or

data tables.

• Examples of Graphs and Tables

Graphing

1. Title graph

2. Independent variable on the X axis

3. Dependent variable on the Y axis

4. Plot data points

5. Make a best fit line

Making Graphs

• Plot the data points

Time

(yrs.)

Height

(cm)

1 5

2 10

3 15

5 25

0 4 3 2 1

5

5

25

20

15

10

Time (years)

He

igh

t (c

m)

Conclusion

• Analyze data (find the average) and compare your results to your hypothesis.

• Graph the data to look for trends and

relationships.

• Was your hypothesis correct?

• Accept a correct hypothesis

or

Conclusion

• Reject an incorrect hypothesis. Give possible reasons for the difference between your hypothesis and the experimental results.

For a rejected hypothesis –

If you were to make another experiment

for this activity, what modification

(change) would you make to your

control?

Share Data

• Share your results with others so that they may repeat the experiment