Variables and hypothesis Flashcards
What are Independent variables?
These are the variable(s) that the experimenter manipulates or changes
What is the IV in this scenario:
A researcher is interested in comparing short-term memory capacity in males and females
The independent variable is gender (he cannot change participants’ genders, but he can assign people of different genders to the experimental groups he uses).
What are Dependent variables?
These are the variables that the experimenter measures - their value depends on how the independent variable has been set. Dependent variables need to be operationalised before they can be measured.
What is the DV in this scenario:
A researcher is interested in comparing short-term memory capacity in males and females
The dependent variable is short-term memory capacity.
What is Operationalising variables?
A variable is operationalised when it has been turned in to something that can be measured. ‘Memory’ is a variable, but how can it be measured? ‘Memory as measured by the number of items correctly recalled from a list after 5 minutes’ is an operationalised variable. Similarly ‘aggression’ could be operationalised as the number of aggressive acts recorded in a 10 minute observation.
What are Extraneous variables?
These are any variables other than the independent variable that may affect the dependent variable in some way.
What is a Directional hypothesis?
A directional prediction of what is expected to happen. It states which condition of the IV will perform better or worse than the other. It must include the DV and be operationalised.
What is an example of a Directional hypothesis?
•Male participants will score more basketball hoops than female participants.
What is a Nondirectional hypothesis?
A nondirectional prediction of what is expected to happen. It states that there will be a difference between the conditions of the IV, but it does not state which will perform better or worse. It must include the DV and be operationalised.
What is an example of a nondirectional hypothesis?
•There will be a difference between male and female participants in the number of basketball hoops scored.
What is a Null hypothesis?
A statement that nothing will happen. It states there will be no difference between the conditions of the IV. It must include the DV and be operationalised. It is an important statement as the purpose of empirical research is to reject or disprove the null hypothesis, and so lend support to the prediction made in one of the experimental hypotheses.
What is an example of a Null hypothesis?
•There will be no difference between male and female participants in the number of basketball hoops scored.
