Research Methods Flashcards
what are the two different types of hypothesis and explain them
- null hypothesis: have no difference or correlation
- alternative hypothesis: show a difference or correlation
what are the two different types of alternative hypothesis and explain them
-directional: a relationship/direction is shown (better/worse)
- non-directional: states there is a correlation or direction but doesn’t specify
what is an independent variable
something the researcher changes or manipulates to observe effects . It is generally the cause of effect
what is a dependant variable
something that is measured to see if there is any change. Generally described as the outcome/effect. The IV is a cause that has an effect on the DV
what does the term operationalisation mean
when the researcher clearly defines the variables in terms of how they are being measured. (more specific)
what is an extraneous variable
a variable that can effect the dependant variable unless it’s controlled. These are factors that can affect the results of the experiment
what is a cofounding variable
a variable that has an effect on the DV. Unlike the extraneous variable, confounding variables do change systematically with the IV.
what are demand characteristics
- cues from the procedure that suggest what the research is about, therefore ppts change behaviour accordingly
what is the investigator effects
- any unwanted influence of the investigator on the research outcome e.g bias to some ppts, or only picking extraverts
what does the term standardisation mean
- a way of controlling extraneous variables by keeping them the same across both conditions
define the term randomisation
- use of chance wherever possible to reduce the researcher’s influence on the design of the investigation
what is a repeated measures design
- the same ppts take part in each condition
- they take part in ALL conditions
what is an independent measures design
- ppts are randomly allocated into different conditions and only participate in that condition
what is matched pairs design
- ppts are paired together based on characteristics/variables relevant to the experiment and then each pair is allocated to one of the conditions. (each partner does a different condition)
what are the strengths of a repeated measures design
- differences can’t be due to individual differences as the same ppts take part in both conditions
- less time is spent recruiting ppts (time efficient)
- researchers are saving money as less ppts are needed
what are the limitations of a repeated measures design
- ppts may perform worse on 2nd condition due to boredom (order effect)
- ppts may do better in 2nd condition due to practise effects
- demand characteristics - guess aim and change behaviour accordingly
to reduce weaknesses: task may need to be changed between conditions to reduce extraneous variables
what are the strengths of an independent group design
- only participate in 1 condition so there will be no order effect or practise effects
- tasks won’t need to be changed, allows control between both conditions
-ppts are less likely to guess the aim, eliminating demand characteristics
what are the limitations of an independent group design
- differences could be due to individual differences
- more ppts need to be recruited, time and cost ineffective
- to reduce weakness: random allocation can help reduce ppts variables
what are the strengths of matched pair design
- no order effects or practise effects
- tasks won’t need to be changed
- ppts variables are accounted for as ppts are matched
- ppts are less likely to guess the aim of study, eliminating demand characteristics
what are the limitations of matched pairs design
- matching ppts can be time consuming and expensive, need to identify key variables and measure them
- can be difficult to know which variables ppts should be matched on
define a laboratory experiment
where the researcher directly manipulates/changes the IV and controls all other variables in a highly controlled environment. Ppts are aware they are taking part in this experiment
what are the strengths and weaknesses of a lab experiment
strengths:
- highly controlled over confounding variables
-highly replicable, standardised procedure
weaknesses:
- demand characteristics, ppts aware they are taking part in study
- low ecological validity- tasks aren’t reflective of everyday
define a field experiment
- carried out in natural environment- real life setting, researcher directly manipulates IV
what are the strengths and weaknesses of a field experiment
strengths:
- less chance of demand characteristics
- higher ecological validity
weaknesses:
-difficult to replicate
-no control over extraneous or confounding variables
- not ethical, lack of consent and deception
define a natural experiment
- researcher doesn’t influence or manipulate study as it is naturally occurring, they just observe and compares data
what are the strengths and weaknesses of a natural experiment
strengths:
- more ethical
- high external validity, dealing with real life issues
weaknesses:
-individual differences
- not easy to replicate
- doesn’t control extraneous and confounding variables
define a quasi experiment
- where the IV is naturally occurring as it is pre-existing within individuals but focuses on this difference in individuals to see the effects on the dependant variable. e.g age, gender or disabilities
what are the strengths and weaknesses of a quasi experiment
strengths:
- high control, replicable
- individual differences, allows comparison between types of people
weaknesses:
- ppts aren’t randomly allocated as IV is pre-existing. Ppts variables could have caused change in the DV
-demand characteristics
what is a target population
entire set of people psychologists are interested in
what is a sample
a group of individuals selected from a larger target population
what is generalisability
applying findings to a wider population
when do we consider a sample as biased
when the sample isn’t representative of the whole population e.g same sex
define random sampling
when all members of the population have the same equal chances of being the one that is selected
what are the strengths and weaknesses of random sampling
strengths:
- unbiased, randomly selected, no experimenter effects
weaknesses:
- time consuming
define systematic sampling
participants are selected using a set ‘pattern’ (sampling frame)
what are the strengths and weaknesses of a lab experiment
strengths:
-highly controlled, extraneous and confounding variables
- highly replicable
weaknesses:
- demand characteristics
-lacks ecological validity, doesn’t reflect every day tasks
define a field experiment
researcher directly manipulates the IV in a natural environment
what are the strengths and weaknesses of a field experiment
strengths:
-less chance of demand characteristics
-higher external validity
weaknesses:
- difficult to replicate
- no control over extraneous or confounding variables
- ethical issues, lack of consent and deception
define a natural experiment
- the researcher doesn’t directly manipulate the IV as it is naturally occurring.
what are the strengths and weaknesses of a natural experiment
strengths:
-more ethical, nothing is being changed or manipulated
- high external validity, dealing with real life issues
weaknesses:
- individual differences, no random allocation
-not easy to replicate
- no control over extraneous and confounding variables
define a quasi experiment
-where the IV is naturally occurring as it is pre-existing within individuals but focuses on this difference in individuals to see the effects on the DV. e.g age, gender or disability
what are the strengths and weaknesses of a quasi experiment
strengths:
-high control over variables so replication is possible
-individual differences, allows comparisons to be made
weaknesses:
- demand characteristics
- ppts not randomly allocated