Research Methods Flashcards
What’s a Null hypothesis
One that is based on the assumption that there is no difference between two conditions or no relationship between two variables
What’s a directional hypothesis (one tailed)
A prediction that states the direction of the difference between two conditions or which states the direction of any correlation between two variables
What’s a non-directional hypothesis (two tailed)
A prediction which states that there will be no difference between conditions or that there will be a correlation but which does not state a direction the difference will go in
What is the independent variable?
The variable that you change, which CAUSES the effect or outcome
What’s the dependant variable?
The variable that we measure which is the outcome of effect of the study.
What’s an alternative hypothesis?
One that States that there is a significant difference between two conditions of a significant relationship between two variables
Extraneous variable?
Any variable that may affect the dependant variable apart from the IV
What is operationalising a variable?
Means to make something clear so that it’s easier and more accurate to measure and makes reproducibility better
What are the experimental designs?
- Independent groups
- repeated measures
- matched pairs
Explain independent groups and it’s benefits and weaknesses
Different participants in each condition of the IV.
Strength- people only do one IV so there is no chance of learning/improvement (practice effects), there’s also no fatigue effects.
Weaknesses- there are participant variables as there’s different people doing each IV.
- usually needs more participants so is practically difficult
Explain repeated measures design and the strengths and weaknesses
Each participant does both conditions of the IV.
STRENTHS- it controls participant variables as both sets of participants do both conditions.
-requires fewer people
WEAKNESSES- it takes longer for each participant to complete it as the do it twice.
- there may be order effects including practice effects or fatigue.
Explain Matched pairs Design and its strengths and weaknesses.
Each person only does one condition of the IV, but are matched with another person doing the other condition on some important extraneous variable (e.g. IQ).
STRENGTHS- there are no problems with order effects
- the research gains control over extraneous variables
WEAKNESSES- the main weakness is that is can be impractical to match people at the beginning of the experiment.
- there are other participant variables that researchers cannot match participants on.
What is counterbalancing in repeated measures design?
Half the participants do conditions in one particular order and the other half do the conditions in the opposite order- this is done to balance possible order effects.
What are the different experimental methods?
- laboratory
- field
- natural And quasi experiments
Lab experiment
Conducted in a controlled environment.
Participants are aware they’re taking part in an experiment but may not know the aim.
Poor ecological validity.
Field experiment
Conducted in real world environments e.g. A hospital ward.
Less likely that participants know they’re in an experiment and there is less control over extraneous variables.
Natural experiment
Where the IV has not been manipulated by the experimenter, but has changed or occurred naturally (the terrorist attacks on 9/11 gave a natural opportunity to study the effects on pregnant women. They’re unplanned.
Quasi experiment
The independent variable has not been manipulated but the experimenter has still carefully planned it. The most common type of experiment is where researchers investigate the differences between men and women on a certain variable.
What is quantitative data
Information from an experiment that is gathers in the form of numbers
What are demand characteristics
The features of a study that may bias the participants to behave in a certain way as they may guess the purpose of the study and change their behaviour (screw you effect)
Define reliability
Extent to which findings of measures have been repeated with similar results of the extent to which a measure is consistent.
Reliability=consistency
Types of reliability
Inter-rater reliability - more than one researcher agrees with one another’s results.
Test-retest reliability - the test is done again on the same sample of participants. Looking for a high correlation between results
Replicability?
The ability to repeat a study over and over in exactly the same way.
Define validity
Results that are accurate and true. Accurately investigates what it intends to.
