Research methods Flashcards
experimental method
changing independent variable to measure effect on dependent variable
aim
a statement outlining the purpose of an investigation
hypothesis
a clear, testable statement stating relationship between variables being used
directional hypothesis
states the direction of the difference or relationship
levels of the IV (independent variable)
to test the effect of the IV, there needs to be different conditions. different conditions are known as levels
operationalisation of variables
the process of defining variables in a way which makes them measurable i.e. referring to specific observable behaviours.
extraneous variables
any variable that isn’t the IV that will affect results if not controlled. two types: participant and situational variables
confounding variable
an EV that affects independent and dependent variables, it’s difficult to tell if results are due to CV or a IV
demand characteristics
cue from a researcher which might affect participants behaviour. please-u effect = acting in a way to please researcher. screw-u effect = acting in a way they think will sabotage the study
investigator effect
anything investigator does which has an effect on participants performance in a study other than intended
randomisation
the use of chance in order to control for the effects of bias when designing materials and deciding the order of conditions
standardisation
using exactly the same formulised procedures and instructions for all participants in a research study
laboratory experiment
conducted in a highly controlled environment
evaluation of lab experiments
+ high control over EVs and CVs so you know that any change in DV is due to IV, giving it high internal validity
+ replication is more possible because of amount of control, making it more valid
- artificial so lack generalisability and have low external validity
- pts are aware they’re being tested so may act unusually
- don’t represent the everyday experience, low mundane realism
field experiment
an experiment conducted in the participants’ natural environment. natural, more everyday setting
evaluation of field experiments
+ higher mundane realism
+ pts may be unaware they’re being studied, more valid + authentic behaviour, high external validity
- no control of EVs and CVs so difficult to establish link between IV and DV
- precise replication is often impossible
- ethical issues of having no consent from pts - invasion of privacy?
natural experiment
no control over the IV and can’t change it.
the IV is always natural but not always the setting - could be in a lab.
DV may also be naturally occurring.
evaluation of natural experiments
+ allows us to study real world issues as they occur, high external validity
- naturally occurring events are rare, reducing opportunities for research, also limiting scope for generalising
- pts may not be randomly allocated, so less sure if IV affected DV
- if conducted in lab = lacks realism
- demand characteristics may be an issue
quasi-experiment
the IV is based on existing differences (e.g. age or gender) so can’t be controlled
random sampling
everyone has an equal chance of being chosen. everyone should have random numbers assigned to them and chosen using a random selection method
systematic sampling
a systematic formula is used – every 50th person is picked from the phone book/school register
stratified sampling
different strata or subgroups are identified in the target population. what percentage of the whole target population does each sub group form? a random sample is taken from each subgroup so that the sample has the
same percentages as the target population
opportunity sampling
the researcher selects people from the target population who happens to be there at the time, and who are willing and able to take part.
volunteer sampling
asking for people to volunteer if they are able to take part in the study