the scientific method - park-science - home. design an experiment experiments have three main parts...

The Scientific Method

I. Identify a Problem

What are you trying to find out? ALWAYS stated as a question

Example Does the amount of water you give a plant

affect how tall it grows?

II. Form a Hypothesis

A hypothesis is written using three parts: If… (explain the situation) And… (what are you going to do, experiment) Then… (what results would you expect)

Example If the amount of water affects plant growth and I

water three plants different amounts of water thenthe plant that receives the most water will betallest.

III. Design an Experiment

Experiments have three main parts Independent Variable

The condition you will change (amount ofwater)

Dependent VariableThe condition you will measure (height)

ControlAnything that stays the same (light, soil, pot,

plant type, air quality, fertilizer, water source)

IV. Test The Hypothesis

DO the experiment Example:

Plant A - water 100 ml every day Plant B - water 200 ml every day Plant C - water 300 ml every day

V. Gather Data

Two types of Data Quantitative - Raw numbers Qualitative - Observations

Example Quantitative

QualitativeThe soil in plant C is always wet and has a

puddle on top

VI. Analyze the Results

Results can be in the form of pictures,data tables, or graphs

Examples

VII. Form a Conclusion

Conclusions should be written inparagraph form and should answer thefollowing questions: Do you support or reject your hypothesis? What data did you collect that leads you to

support or reject your hypothesis? What were some possible sources of error

(PSOE) - at least two.

Conclusion Continued…

Example:

Based on the data, I reject my hypothesis.During my experiment I found that plant Bgrew the most, but was watered less thanplant C but more than plant A. Twopossible sources of error could be notenough sunlight or poor soil quality.