RESEARCH METHODS Flashcards
Define aim
What researcher intends to investigate
Define hypothesis
Clear, precise and testable statement that states the relationship between variables being investigated
Define variable
Factor that can be changed in an investigation
Define independent variable
Experimental situation that researcher manipulated or it changes naturally
Define dependent variable
Measured by the researcher to see how it changed
Define operationalisation
Turning abstract concepts from your aim into clearly define variables that can be measured
Define directional hypothesis
Kind of difference/relationship between IV and DV(one-tailored hypothesis)
Define non-directional hypothesis
Predicts that there will be a difference between conditions but can’t predict which direction it’ll go (two-tailored hypothesis)
How do researchers decide what type of hypothesis to use
One tailed if previous research suggests an outcome.
Two tailed if no previous research or it’s inconclusive
Define extraneous variables
Any variable other than the IV that may have an effect on the DV (if it is not controlled).
Define confounding variables
- Do systematically change with the IV.
- Any variable other than the IV that may have affected the DV so we cannot be sure of the true reason for the DV changing.
e.g. personality
Define investigator effects
- Any effect of the researcher’s behaviour that could change the outcome of the results (DV).
e.g. smiling more when lying
How can extraneous variables and confounding variables be controlled?
- Standardisation > All participants should be subject to the same experimental condition (i.e. environment, time etc).
Randomisation > Using chance in order to control for the effects of bias in an experiment.
Define participant and population
- Participant-people who take part in the research
- Population-group of people from whom the sample is drawn
Why does sample must be representative
in order to generalise your findings from your sample to the population
Whats random sampling
- Every member of the target population has an equal chance to be chosen
1) Compile a list of all target population
2) Assign each name and number
3) Select a sample using random number generator
Advantages of random sampling
- No researcher bias
- Increased internal validity > confounding & extraneous variable distributed between two groups.
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
What’s systematic sampling
- Every nth member of the target population is selected
1) Create a list of the target population in order (sampling frame)
2) Take sample from list
Advantages of systematic sampling
- Objectives > avoids researcher bias > researcher has no influence once the sample is chosen
Disadvantages of systematic sampling
- Could still draw a non-representative sample
- Time consuming > costly
- Participants may refuse to take part
What’s 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 subgroup are selected randomly in the same proportion as the target population
Advantages of stratified sampling
- Avoids researcher bias
- More representative of the whole population > findings are more generalised
Disadvantages of stratified sampling
- Stratification is never perfect > complete representation of population is not possible
What’s opportunity sampling
Sample from people who are available and willing when the study is carried out (e.g. psychology undergraduates).
1) Select whoever is available at the time.
No need to obtain a list of the target population.
No need to devise a method of random selection - saves time.
Advantages of opportunity sampling
- Quick
- Convenient
- Less costly
Disadvantages of opportunity sampling
- Unrepresentative of the target population > cannot generalise
- Researcher controls selection so may avoid certain people > researcher bias.
What’s volunteer sampling
Self-selected sampling – participants become part of the study when asked or in response to an advert.
Advantages of volunteer sampling
- Convenient.
- Less time consuming.
- No researcher bias.
Disadvantages of volunteer sampling
- Often unrepresentative. Volunteers may have similar profile (e.g. people with spare time) > volunteer bias.
Define experimental design
How you allocated your participant to the different conditions in an experiment
List the 3 experimental designs
- Independent group
- Repeated measures
- Matched pairs
What’s independent group
- Participants take part in 1 condition
-Required a separate group for each condition then results for each group, usually by comparing mean results
Advantages of independent groups
- Avoids order effects > reduces boredom and fatigue
- Reduces demands characteristics
Disadvantages of indepedent groups
- Needs lots of participants > costly
-Difference between groups (participant variables) > may affect result; however random allocations can overcome this
Define order effects
When the order of the conditions in an experiment has an effect on participant behaviour.
What’s repeated measures
- Participants do all conditions
- Results compared at the end
Advantages of repeated measures
- Avoids participants variables as everyone does all the conditions
- Fewer people needed > less costly
Disadvantages of repeated measures
- Order effects more likely > requires counterbalancing
- Demand characteristics more likely as participants are more likely to guess the aim.
Define counterbalancing
Alternating the order in which participants take part in different conditions.
e.g. 1) control followed by experiment
2) experiment followed by control
Define matched pairs
- Participants are matched in each condition for any characteristics that may affect performance. E.g. age, gender, IQ.
- Results are compared between members of each pair.
Advantages of matched pairs
-Reduces participant variables
- Reduces order effects and demand characteristics
Disadvantages of matched pairs
- Very time-consuming > costly
- Impossible to match pairs exactly (even for twins) > may be unexpected confounding variables.
Confounding variable
A kind of extraneous variable that systematically change with the IV.
Any variable other than the IV that may have affected the DV so we cannot be sure of the reason for the DV changing.
Participant variable
any individual differences between participants that may affect DV
Situational variables
any features of the experimental situation that may affect DV
Examples of participant variables
Personality, age, gender, motivation
Examples of situational variables
weather, instructions, temperature, time of day, noise
Demand characteristics
Any cue from the researcher or from the research situation that may be interpreted by participants as revealing the purpose of an investigation. This leads to a participant changing their behaviour within the research situation
How can we control extraneous and confounding variables ?
1) standardisation- All participants should be subject to the same experimental conditions
2)Randomisation- Using chance in order to control for the effects of bias in an experiment
Order effects
When the order of the conditions in an experiment has an effect on particular behaviour
counterbalancing
Alternating the order in which participants take part in different conditions
What is an experiment ?
There is an IV sometimes manipulated by the researcher
The effects of the IV on the DV are observed or measured so that the hypothesis can be tested
The participants are allocated randomly to the conditions, where possible.
lab experiments strengths
control extraneous variables- increases objectivity + validity
- can be standardised, easy to replicate
Lab experiments limitations
Artificial conditions-low ecological validity, demand characteristics, experimenter bias, low mundane realism, ethics
difference between field and natural experiment
natural also takes place in a real life setting but unlike field, researcher has no control over either the environment or variables so iv is therefore likely to be naturally occuring