Pearson's correlation Flashcards
what type of data is a correlation used?
relationship between 2 continuous variables where there is no clear DV or IV
what type of graph is used for a correlation?
scatter graph (each dot = 1 person with one score on the x variable and a score on the y variable, looking for a linear pattern)
what are the different types of conclusions that can be drawn from a scatterplot?
X has caused Y, Y has caused X, relationship can be explained by a 3rd variable, relationship is purely chance
explain the difference between correlation and causality
correlation results can’t tell us which conclusion is the correct one as correlation doesn’t infer causality
what are the 2 aspects of the correlation coefficient (r)?
direction (positive or negative relationship) and strength (0-1)
the more data resembling a straight line, the ______ the correlation will be
stronger
a strong relationship will have a correlation coefficient (r value) above?
0.7
can be + or -
correlation coefficient =
measure of effect, gives indication of strength of relationship
what would be the H1 and H0 of a correlation analysis?
H0 = correlation would be 0, h1 = correlation unequal to 0
what size would we want the p value to be in a correlation analysis?
p value as small as possible so the chance that there is no relationship in the population to be as small as possible
identity the assumptions that need to be met in order to use a correlation analysis
data is normally distributed, no clear outliers, ASSUMPTION OF LINEARITY
explain the assumption of linearity in a correlation analysis
must be a linear relationship between the 2 variables (can’t be a u shaped curve)
how will the 2 continuous variables be presented in SPSS?
vlQ and slQ
the proportion of variation in scores in one variable can be explained by the variation in the other variable =
shared variance
with shared variance, the stronger the relationship means there is _____ overlap so _____ variance they share
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