research methods Flashcards
independant variable
variable manipulated by the researcher.
dependant variable
variable measured by the researcher to observe change due to IV
controlled variable
other variables that the researcher controls to ensure changes to DV is solely due to IV
3 types of psychological studies, briefly explain each
- controlled experiments (effect of IV on DV observed while other variables are controlled)
- case study (investigation of situation that includes complexities of real world)
- correlational study (researchers observe effect of IV on DV without active control or manipulation)
3 controlled experimental designs, briefly explain each
- within subjects (same participants are used for control and experimental group)
- between subjects (different participants are used for control and experimental group)
- mixed design (contains elements of both designs)
3 sampling techniques
- convenience sampling
- random sampling
- stratified sampling
extraneous variables
variables other than IV that may cause an unwanted effect on the DV.
confounding variables
extraneous variable that was not controlled for, and has now directly affected the DV
examples of extraneous variables
only need to say a few
- participant-related variables (participant differences)
- order effects
- placebo effects
- experimenter effects (bias)
- non-standardisation
- demand characteristics
how can extraneous variables be prevented
only need to say a few
- sampling size/method
- experimental design choice
- counterbalancing
- placebo
- single-blind procedure
- double-blind procedure
- standardisation
- controlled variables
primary + secondary data
primary data is sourced from first-hand experience.
secondary data is sourced from other’s prior research.
qualitative + quantitative data
quantitative data is numerical.
qualitative data is non-numerical.
objective + subjective data
objective data is factual and free of personal opinion.
subjective data is informed by personal opinion.
measures of central tendency, briefly explain each.
- mean (average)
- median (central figure)
- mode (most common figure)
measures of variability
- range
- standard deviation
accuracy
how close a measurement is to the true value of the quantity being measured.
true value
value that would be found if quantity could be measured perfectly.
precision
how closely a set of measurement values agree with each other.
systematic errors
errors in data that differ from true value by a consistent amount. affects the accuracy of the measurement.
random errors
errors in data that are unsystematic and occur due to chance. affects the precision of the measurement.
repeatability
extent to which successive measurements produce the same results when carried out under identical conditions within a short period of time.
reproducibility
extent to which successive measurements produce same results when repeated under different conditions.
validity
extent to which psychological tools/investigations truly support findings and conclusions.
internal validity
extent to which an investigation truly measures/investigates what it claims to.
