whether the IV changed the DV or if it was something else
external
extent to which generalisaility is possible
population
to other people
temporal
depends on the time it was done
ecological
settings it was done in
face
what extent the method measures what it is supposed to
concurrent
assessed by comparing results with another well established, well recognised test
Threats to internal validity
Demand characteristics
P variables
might act extraneous ONLY with indepedent design
Situational variables
order effects
time of day
temperature
noise
investigator effects
Experiments
control groups
standardisation
use of single or double blind procedures
Observations
consider covert
no broad/ overlapping categories
trained observers
Questionnaires
a lie scale (a set of items within a psychological instrument (particularly a personality assessment) used to indicate whether a respondent has been truthful in answering.)
reassure Ps about anoymity
ask expert to look over it
Qualitative methods
write up uses Ps quotes to back up analysis
triangulation- variety of different sources as evidence
