Research Methods Flashcards
What is a null hypothesis?
The assumption that there is no difference between two conditions or no relationship between two variables. (Any difference seen is considered a coincidence).
What is a directional hypothesis?
A prediction that states the direction of the difference between two conditions or which states the direction of any correlation between two variables.
What is a non-directional hypothesis?
A prediction that states that there will be no difference between conditions or that there will be a correlation but which does not state the direction.
What is an extraneous variable?
Any variable which may affect the dependent variable other than the IV.
Why do researchers try to control or eliminate extraneous variables?
To make it a fair test.
What does an alternative hypothesis state?
That there is a significant difference between two conditions or that there is a significant relationship between two variables.
What does the confounding variable affect?
The dependent variable
It also varies systematically with the independent variable
Explain the independent groups, experimental design.
Different participants in each condition of the IV.
Explain the repeated measures, experimental design.
Each participant does both conditions of the independent variable.
Name a strength and a weakness of the independent groups, experimental design.
Strength - there is no chance of learning or improving between the first time they do the experiment and the second time.
Weakness - there may be difference between the participants, participant variables.
Order effects may be present in the repeated measures, experimental design, explain what this is.
Where a person may either be better the second time due to practice, or be worse due to boredom/fatigue.
Explain the matched pairs, experimental design.
One person does one condition of the IV, but are matched with another person doing the other condition on some important extraneous variable.
Explain counterbalancing.
Half the participants in one particular order and the other half do the conditions in the opposite order.
Explain why counterbalancing is done.
To balance possible order effects.
Name an advantage and a disadvantage of a lab experiment.
Advantage - done in a controlled environment, reduced extraneous variable, easily repeated, reproducible.
Disadvantage - demand characteristics are likely, low ecological validity
Name a pro and a con of a field experiment.
Pro - higher ecological validity, natural environment, no demand characteristics
Con - low control, increased extraneous variables, not as easy replicated
Name an advantage and a disadvantage of using standard deviation.
Advantages - much less affected by outlying results, allows us to understand where an individual score lies in relation to the general population, shows us the variability of the data.
Disadvantages - hard to interpret data if not normally distributed, harder to calculate the range.
What is the target population in relation to a psychological study?
Group of people you’re interested in studying, the population you want to generalise the findings of your study to.
How does random sampling work?
Every member of the target population has the same chance of appearing in the sample.
What is opportunity sampling, what’s a pro and a con?
The researcher uses whoever is available from the target population at the time.
Pro - quick
Con - can be biased
What is volunteer sampling?
What’s a pro and a con?
Participants choose themselves by doing a questionnaire or answering an advertisement.
Pro - quick
Con - not a representative sample
Give the 4 demand characteristics.
- participants may want to appear ‘normal’
- participants may guess the aim and act how they think the investigator wants them to act.
- they may deliberately try to behave unexpectedly
- participants may attempt to look socially desirable
Name 3 examples of investigator effects.
- researcher may unwittingly influence the participants behaviour
- researcher may interpret data wrong
- an attractive researcher may cause demand characteristics.
Which experimental design did Peterson and Peterson’s (1959) study on STM use?
Repeated measures
