Scientific Research

Sci

enti

fic

Meth

od

• Make an observation

• Ask a testable question

• Form a hypothesis

• Design and perform an experiment to test hypothesis

• Repeat experiment

• Analyze data

• Draw Conclusions

• Share

Ob

serv

ati

on

s an

d In

fere

nce

s • Observation

• What you see

• Inference

• What you think

• Example:

• You observe that the sky is darkening.

• You infer that it is about to storm.

About Hypotheses• Avoid the phrase “educated guess”

• Instead, think of a hypothesis as a “proposed answer to a scientific question”

• Scientists will do plenty of research about their topic before forming a hypothesis

About Experiments• Every experiment needs:

• A control

• Constants

• Independent variable

• Dependent variable

• Scientists should design an experiment that will thoroughly test their hypothesis

• Results of experimentation should always be compiled and shared

Contr

ol

s• The control group is not

exposed to experimental conditions

• Used for comparison

• The group that is exposed to experimental conditions is the experimental group

Const

an

ts• Variables that are

controlled for a held constant

• This way we can test one single variable and we can feel confident that our experimental results are due to that variable and not something else

Ind

ep

end

ent

Vari

ab

le

• A condition that is manipulated

Dep

end

en

t Vari

ab

le• A condition that is observed or measured

Data

• Qualitative data

• Think QUALITY

• Observed, but not measured

• Smell, taste, color, texture etc.

• Quantitative data

• Think QUANTITY

• Measured

• Height, temperature, weight etc.

Exam

pl

e!

• You want to see if a certain blood pressure medication will lower the blood pressure of people with hypertension (high blood pressure).

• Control

• people with high blood pressure that are NOT given the medication

• Constants

• age, weight, general health, gender, amount of medication given, diet

• Independent variable (X axis)

• Ask: Which variable can be manipulated to cause a change in the other variable? The medication can be manipulated to cause a change in the blood pressure (while blood pressure cannot be manipulated to change the medicine).

• Dependent variable (Y axis)

• Ask: Which variable is dependent on the other? The blood pressure of the person depends on the dosage of their medication.

• Qualitative Data

• Patient appears pale and tired while on medication

• Quantitative Data

• Systolic and diastolic blood pressure was reduced, on average, by

• 10 mmHg

Assignment!• Complete the scientific method practice sheet