research methods Flashcards
(103 cards)
Aim
A general statement of what the researcher intends to investigate. This is the purpose of the study.
E.g. An investigation into how colour of text affects recall of words.
Hypothesis
A clear, precise and testable statement that states the relationship between the variables to be investigated.
e.g. words will take longer to recall if they are presented in the same colour as the meaning of the word.
Variables
A factor that can change in an investigation.
Independent Variable (IV)
An aspect of the experimental situation that is manipulated by the researcher or changes naturally so the effect on the DV can be measured.
Dependent Variable (DV)
The variable that is measured by the researcher. Any result/change on the DV should be caused by the change in the IV.
directional hypothesis
states the kind of difference or relationship between the IV and the DV. It is sometimes called one-tailed hypothesis.
non-directional hypothesis
simply predicts that there will be a difference between conditions (but does not predict which direction it will go). It is sometimes called two-tailed hypothesis.
Extraneous variables
Any variable apart from the IV which can effect the DV if not controlled. However they can be maintained or eliminated.
Confounding Variables
A variable apart from the IV which can effect the DV. However it can’t be controlled.
Demand Characteristics
Any cue from the researcher or research situation that can be interpreted by participants as revealing the purpose of the investigation leading them to changing their behaviour.
Experimenter Effects
Where the experimenter changes a persons views usually sub-consciously through body language.
How can we control extraneous and confounding variables?
- Standardisation
-All participants should be subject to the same experimental condition (i.e. environment, time etc).
-Standardised instructions (scripted/recorded). - Randomisation
-Using chance in order to control for the effects of bias in an experiment.
-E.g. Randomly allocating questions to participants.
Conditions could be randomly allocated.
Participants
people who take part in research.
Population
the group of people from whom the sample is drawn.
Bias
when certain groups are under- or over-represented in a sample (not representative).
Random Sampling
Every member of the target population has an equal chance of being chosen.
1.Compile a list of all target population.
2.Assign each name a number.
3.Select sample using a random number generator (e.g. computer or draw from a hat).
advantages of random sampling
+No researcher bias.
+Confounding variables should be distributed evenly – improves validity.
disadvantages of random sampling
-Difficult to get a complete list of target population.
-Time consuming.
-Participants may refuse to take part.
-May randomly draw a non-representative sample.
Systematic Sampling
Every nth member of the target population is selected (e.g. every 5th person on the register).
1.Create a list of the target population in an order (e.g. alphabetical) – this is the sampling frame.
2.Take a sample from this list.
advantages of systematic sampling
+Objective - avoids researcher bias. Researcher has no influence once system is chosen.
disadvantages of systematic sampling
-Could still draw a non-representative sample.
-Time consuming and costly.
-Participants may refuse to take part.
Stratified Sampling
Composition of the sample reflects proportions of certain subgroups in the target population.
1.Identify different subgroups in the population.
2.Work out proportion of each group.
3.Participants in each sub group are selected randomly in the same proportions as the target population.
advantages of systematic sampling
+Avoids researcher bias.
+More representative of the whole population so findings are more generalizable.
disadvantages of systematic sampling
-Stratification is never perfect. Complete representation of population is not possible.
