Week 1: Statistics Flashcards
Central tendancy/spread
Mean, Median, Mode
Variance/DS
DS is just the route of the variance, it is in the same units as the data
Inferential stats
Use the sample to infer things about the population
H0
H0: There is no difference between groups
P-value
Probability of obtaining a difference as big as the one that we found when there is actually no difference
Usually .05
Less than 5% chance we would have obtained this big of a difference if there was none
Differences between 2 groups tests (2)
T-tests (two groups)
ANOVA (more than 2 groups)
Are 2 continuous variables related to each other?
correlation (r)
H0 r=0
Are multiple continuous variables related to each other?
Main effects
Interaction
Moderation
multiple regression
Multiple IVs and one DV
Unique association of each IV with DV (beta)
MAIN EFFECTS account for the effect of one IV on the DV after accounting for the effect of the other IVs
The beta value is the unique variance in the DV explained by this IV alone
INTERACTION EFFECTS are when the association between one Iv and the DV varies as a function of another IV
They act as MODERATOR VARIABLES
Interaction effects are shown with different gradients or crossing over on line graphs. If the lines are parallel, no interaction effects.
E.g. negative emotionality moderates the association between childcare quality and behavior problems and social skills at 4.5 years
IV negative emotionality
IV childcare quality
DV behavior problems and social skills at 4.5 years
NO MAIN EFFECT for either IV
INTERACTION EFFECT for the two
Negative emotionality moderates the association between childcare quality and behavior problems and social skills at 4.5 years. On average, children with high negative emotionality show higher social skills and less behavior problems at 4.5 years if they had good childcare and worse social skills and behaviour issues if they have lower quality childcare. This is not true for kids with low negative emotionality.
