Final Exam
how do you interpret r as a slope
A one SD change in X is associated with an r SD change in Y
What does negative correlation mean
As one variable goes up, the other goes down
which assumptions apply to methods comparing multiple variables (and not single variables)?
Bivariate normality and homogeneity of variance
What are the key pieces of information needed to calculate confidence intervals
The SE or SD, the point estimate, the critical value
What is correlation a measure of
How related two variables are
Which of the following can invalidate or bias your correlation
Curvilinear relations, truncated scores, outliers
Which is used as the criterion for creating an OLS regression line
Minimizing the error, or squared difference from the predicted amount
What does it mean to reject the null when testing correlation
To conclude that the relationship between the two variables is not due to chance - there is a non-zero relationship in the population
What is the difference between a point estimate and an interval estimate
a point estimate gives a single number to represent an unknown population parameter, and an interval estimate gives a range of numbers
what is the relation between confidence intervals and null hypothesis testing
for the correct alpha for the chosen C, we can reject the null if the null is not in the confidence interval
which assumption is always included
independent and random sampling
What is the relationship between the correlation coefficient r and the regression coefficient b
r is standardized b
what is the relationship between r and the proportion of explained variance
r squared is the proportion of explained variance
how do you account for paired data
remove the variability due to the relatedness of the pairs by subtracting out the correlated variance
what does a significant b mean
the relationship between x and y (the slope) is probably not due to chance
what is b
the slope
what is homogeneity of variance
the variance (SD) of both populations is the same
which of the following is a correct interpretation of a confidence interval
we arre 95% confident that the population parameter lies within the confidence interval
When do you use a paired-sample t-test
when you can meaningfully and correctly match observations (participants) across samples
a paired sample t-test looks at which kind of information
within-pair