part 1 Flashcards
what does the term operationalism mean
when we define exactly how a variable is going to be measured.
what is validity
Validity refers to whether a study or test is measuring what it claims to be measuring
what is external validity
External reliability refers to how consistent the results of a study or specific test are.
what is internal validity
Internal reliability refers to how consistent the results are of individual items on a test or questionnaire.
what is face validity
Face validity refers to whether a test appears to be measuring what it claims to measure
what is concurrent validity
Concurrent validity refers to whether a test shows similar results to another test, that is already known to be valid, and that aims to measure the same thing.
what’s two ways to prevent investigator effects
Investigator effects can be prevented by using standardisation, and by conducting a double-blind study.
How can a researcher reduce the likelihood of demand characteristics?
by using a single-blind study, so that participants do not know which experimental group they are in.
what is an extraneous variables
something other than the independent variable that can affect the dependent variable.
participant variable
type of extraneous variable in which the personal characteristics of a participant influence their behaviour and responses during a study.
what is meant by situational variable
type of extraneous variable, referring to anything external to the participant or researcher, that may affect the results of the study
what is meant by investigator effects
Investigator effects occur when a researcher influences the results of their study
what is demand characteristics
Demand characteristics are aspects of the study which lead participants to guess the aim of the study and form expectations about how they should behave.
what is meant by random allocation
Random allocation is way to control for participant variables, by assigning participants at random to either the experimental or control group .
What is one limitation of matching or a matched pair design?
A limitation of matching is that we cannot control for every possible participant variable that could affect the results of the study.
What is meant by a single blind study?
In a single blind study, participants are not aware of which experimental group they are in, but the researcher is aware.
What is meant by a double blind study?
In a double blind study, both the active researcher and participant are not aware of which experimental group the participant is in.
How can a researcher reduce the likelihood of demand characteristics?
A researcher can reduce the likelihood of demand characteristics, by using a single-blind study, so that participants do not know which experimental group they are in.
What is meant by the split-half method?
The split-half method is a way to test the internal reliability of a test or questionnaire. This is done by comparing the results of one half of the test with the second half, to see if the two halves obtain similar results.
What is meant by the test-retest method?
The test-retest method is a way to test the external reliability of a test or questionnaire. This is done by using the same measure, on the same group of participants, at different timepoints, to see if the results are consistent.
What are two ways to assess validity?
Two ways we can assess validity include testing the face validity of a study or measure, and testing the concurrent validity of a measure.
What is one way to assess external reliability?
External reliability can be assessed using the test-retest method.
What is one way to assess internal reliability?
Internal reliability can be assessed using the split-half method.
what is ecological validity
the results of a study generalise to how people behave in everyday life
what is temporal validity
when the results generalise across time
what is population validity
when the results of a study generalise to the rest of the population that the researcher wants to study
higher when sample includes multiple subgroups of the population
what is sampling
when researchers pick a sample from the population. this must be representative
what is volunteer sampling
when researchers post an advert and wait for people to volunteer. eg advert
pros and cons of volunteer sampling
+ easy, and can reach lots of people
- not very representative of the population
what is opportunity sampling
when a researcher approaches members of the population who are willing and available to be participants
pros and cons of opportunity sampling
+ quick and easy to sample participants
- not very representative of the pop
what is systematic sampling
pickings every nth person from the entire population. to do this we need some kind of list of the whole population
what are the pros and cons systematic sampling
+ more representative sample than volunteer or opportunity - samples from whole pop
- more difficult to do as it requires a list of the whole population
- if there’s a pattern in how the pop is listed, the sample may not be representative of the pop
what is random sampling
when a researcher chooses participants at random from a list of the entire population. this means that every member of the pop has an equal chance of being a participant
what are the pros and cons of random sampling
+ more likely to be representative as everyone in the pop has an equal chance if being chosen
- more difficult then systematic, need a list and a way to randomise sample
- representative sample is not guaranteed
Rank the four types of sampling we have seen from least to the most representative.
least volunteer opportunity systematic random stratified most
Rank the four types of sampling we have seen from least to most difficult.
least volunteer opportunity systematic random stratified
what is stratified sampling
sample so that there sample has the same proportion of each subgroup as the total pop
what are the steps for obtaining a stratified sampling
- identify important subgroups within your population
- identify how many people you need from each subgroup for your sample to match the original pop
- sample randomly from each subgroup until you reach the desired proportion
pros and cons of stratified sampling
+ more representative than all other types of sampling, generalise to whole pop
- researchers may miss out important subgroup by mistake
- time consuming and get complicated