Hypotheses and Variables

A hypothesis is...

• what the researcher measures

• something unwanted that can affect results

• a testable prediction

• what the researcher changes or compares

The dependent variable is...

• what the researcher measures

• something unwanted that can affect results

• a testable prediction

• what the researcher changes or compares

The independent variable is...

• what the researcher measures

• something unwanted that can affect results

• a testable prediction

• what the researcher changes or compares

An extraneous variable is...

• what the researcher measures

• something unwanted that can affect results

• a testable prediction

• what the researcher changes or compares

In a study of the effect of a driver training program on driving skill, a possible operationalisation of the dependent variable would be...

• driving quality
• number of accidents
• hours spent training
• amount of traffic

There will be no relationship between variable X and variable Y. What type of hypothesis is this?

• Directional hypothesis

• Non- directional hypothesis

• Null hypothesis

Which of the following is a null hypothesis for a study of the role of aerobic exercise on one's mood?

• 16-year-old female participants who run on a treadmill for 30 minutes will score lower on a test for depressive symptoms than those that do not exercise.

• 16-year-old female participants who run on a treadmill for 30 minutes will score either higher or lower on a test for depressive symptoms than those that do not exercise.

• There will be no significant difference in the scores of on a test for depressive symptoms among 16-year-old female participants.

A teacher wonders if students would do better in IB psychology if the class were more visual. How could you write a research hypothesis for this proposal?

Answer explanation

An example answer:

"The regular use of visual materials in the teaching of the IB Psychology course will lead to higher IB exam performance than when no visual materials are used."

A teacher conducts an experiment to see if listening to music whilst studying will help academic grades. How could you turn this into a null hypothesis?

Answer explanation

There will be no difference in the academic grade of students who listen to music whilst studying, compared to students who do not listen to music whilst studying. Any difference will be due to chance.

How can you "operationalize" verbal aggression?

• Yelling at someone

• Kicking someone

• The number of insulting comments per hour.

• Giving someone the silent treatment.