reliability and validity

Question 1

internal validity

Answer 1

extent to which the effect is due to the IV and nothing else

needs to thus avoid confounding variables

Question 2

threats to internal validity

Answer 2

history- normally takes a while to collect data- changes may be political, natural disaster, pandemic

sampling- relates to a method used (which creates most issues with bias)- random sampling should be best- pre-screening ppts

attrition/potential mortality- drop out rates- certain types of people may drop out

maturation- e.g. studying children- ppts change over time

testing and instruments- testing multiple times using same measures = order effects/practice effects
may need to design equivalent tasks
using different researchers can also have an impact

Question 3

rosenthal/pygmalion effect

Answer 3

high expectations lead to high performance

Question 4

ways of improving internal validity

Answer 4

• standardised procedures= the way u treat every ppts is the same e.g. if using a placebo it should look the same as the actual drug
• counterbalancing=reduce order/practice effects
• blinding= ppt or researcher or both blinded to what condition ppt is in

Question 5

external validity

Answer 5

how our results generalise out of the context e.g. ecological validity- real life settings or population validity

WEIRD samples effect this

Question 6

reliability

Answer 6

extent to which measures are reproducible or consistent over time

Question 7

external reliability

Answer 7

test re test-correlations of one time and another time

inter-observer or inter-rater= extent to which researchers agree in their ratings of coding.

Question 8

internal reliability

Answer 8

internal consistency of the test
e.g. scoring consistently on a personality questionaire

common measure this- cronbach alpha

Question 9

why is validity and reliability important

Answer 9

credibility of research
scientific rigor
ensure findings don’t conflict with each other

Question 10

true experiments and rtc validity

Answer 10

internal validity high

external validity low

Question 11

correlation validity

Answer 11

internal validity low

external validity high

Question 12

questionnaires validity

Answer 12

• face validity- extent to which a questionnaire is evidently measuring what it is supposed to
• content validity- do the items/content tap into what we are trying to measure
• criterion validity- is the questionnaire if tested do different groups of people perform differently
• construct validity- theory around the construct- how close are our interpretations of the construct actually exist and how do we actually measure this construct