Scientific MethodScientific Method

Chapter 1: Section 2Chapter 1: Section 2

How Scientists WorkHow Scientists Work

NotesNotes

Observation vs InferenceObservation vs Inference

ObservationObservation

The act of noticing and The act of noticing and describing events or describing events or processes in an processes in an organized way.organized way. Using your sensesUsing your senses

The object is redThe object is red The object smells fruityThe object smells fruity

InferenceInference A logical interpretation A logical interpretation

based on what scientists based on what scientists already know.already know.

The organism is an The organism is an aquatic organismaquatic organism

The cat is on fireThe cat is on fire

List 3 Questions based on your observations and inferences:

Step 1: State the Question

Step #2 State the Hypothesis: Hypothesis: “An educated guess” a middle school

definition Hypothesis: A scientific explanation for a set of

observations that can be tested and can be proved or disproved

***The hypothesis should include the manipulated variable (independent) and responding variable (dependent) ***

Step 3: Design a Controlled Experiment

Term Definition 

Example 

Controlled Experiment: 

 An experiment where only 1 variable changes

Controlled Variable: 

All parts of the experiment that are the same. 

Manipulated Variable: 

 The variable that is being deliberately changed.

Responding Variable: 

 What is being measured…. Aka your data for the experiment.

Control: The experiment ran under normal conditions.

Step 3: Design a Controlled Experiment

Term Definition 

Example 

Controlled Experiment: 

 An experiment where only 1 variable changesMiracle grow is added to plant A  and all other variables are the

same.

Controlled Variable: 

All parts of the experiment that are the same. Amount of water, soil, sunlight,

etc. 

Manipulated Variable: 

 The variable that is being deliberately changed. Miracle grow 

Responding Variable: 

 What is being measured…. Aka your data for the experiment.

Plant growth

Control: The experiment ran under normal conditions.Plant with only normal soil.

(This is used for comparison purposes)

Step 4: Gather and Analyze Data

Qualitative Data

 Quantitative

Data

Definition:Characteristic Value

 Definition:

 Numeric Value 

Examples: red, softball-sized, cold, violent reaction  Example: 1 mL, 2,000 meters, 10 inches 

Step 5: Make a Conclusion

Your conclusion should include the following:•A bold sentence stating whether you prove or disprove your hypothesis•Explain any experimental errors•List improvements•Change your hypothesis that you could retest (if you proved your hypothesis wrong) or explain how you could use your hypothesis to come up with another experiment to test (if you proved your hypothesis right)

Try writing a conclusion based on the miracle grow experiment!