Save
RM1
week 7
Save
Share
Learn
Content
Leaderboard
Share
Learn
Created by
Susan Denkiewicz
Visit profile
Cards (14)
what happens to a t distribution if degrees of freedom are high enough
matches the
normal distribution
in t tests degrees of freedom are equal to
n -
number of groups
when do we use one-tailed tests
when
previous research
suggests a direction the data may head in
what is the p-value often used in psychology
0.05
What does Neyman-Pearson say
often when looking at the
null hypothesis
people fail to look at the long-term effects, this is where type 1 and type 11 errors are seen
incorrectly accepting the null causes a
type 1 error
incorrectly rejecting the null causes a type 11 error
P(Type 1 error) =
alpha
P(Type 11 error) =
beta
if p =
0.05
, alpha =
5%
standard value of acceptance level of beta is
0.2
meaning that
20%
of time we accept H0 incorectly
What is a within subjects experiment
repeated measures design
evaluate a within subject design
fewer
ppts
eliminates
individual differences
time-related threats
may interfere
order effects
may interfere
participant attrition
what are the 5 types of time-related threats
history - personal changes during study
maturation
- psychological or physical effects
instrumentation
- instruments used to measure DV
testing effects
- effects experienced as a result of prior condition (order effects)
statistical regression
- extreme scores may become less extreme due to statistical regression
what is the carryover effect
when an
experimental
condition may have a lasting effect on
ppts
going through it
what is contrast effect
when
subjective
perceptions of
experimental
conditions may contrast to that of the last one causing an effect on the results
what are examples of progressive error
practice effect
- ppts become better at the condition because they practiced
fatigue
- become worse at the condition
How can we control for the effects relating to a within subjects experiment
controlling time - ensuring the times between each condition are not so long that
time-related threats
interfere
switching to
between subject design
counterbalancing
evaluate
counterbalancing
causes order effects in some ppts but not all so increases
variance
in the study
asymmetrical
order effect
number of conditions - may not be possible due to number of conditions in the study
why are two-treatment designs less convincing than multiple-treatment designs
are not as good at establishing a
cause-and-effect relationship