PY 211 Chapter 15 True/False
The formula for the Spearman correlation coefficient was derived from the formula for the Pearson correlation coefficient
True
The formula for the phi correlation coefficient was derived from the formula for the Pearson correlation coefficient
True
The formula for the point-biserial correlation coefficient was derived from the formula for the Pearson correlation coefficient
True
The sign (+ or -) of a correlation coefficient indicates the direction of a relationship between two factors
True
The value of the sum of products can be positive or negative
True
Three assumptions for a correlation are homoscedasticity, linearity and normality
True
To summarize correlations, we report strength, direction & the p-value for each correlation coefficient
True
The closer that data points fall to the regression line, the more closely two factors are related
True
The coefficient of determination is mathematically equivalent to eta-squared
True
The correlation coefficient can be converted to a chi square statistic
True
Linearity is the assumption that the best way to describe a pattern of data is using a straight line
True
Outliers can change both the direction & strength of a correlation
True
A correlation of r=.50 in a sample of 15 participants is statistically significant for a two-tailed test at a .05 level of significance
False
A positive correlation is always stronger than a negative correlation
False
If r=0.026 and df=10, then t=7.20
False
Restriction of range occurs when an unanticipated variable not accounted for in a research study that could be causing or associated with observed changes in one or more measured variables
False
The assumption of normality requires that the range of scores observed in a sample is the same of the possible range of scores in the population
False
The coefficient of determination is a measure of significance
False
The coefficient of determination is the square root of the correlation coefficient
False
The denominator of the pearson correlation measures the extent to which two factors vary together
False
The point-biserial correlation coefficient is used to measure the correlation b/w 2 dichotomous variables
False
The spearman correlation coefficient is used to measure the correlation b/w two nominal variables
False
A correlation of r=.38 in a sample of 30 participants is statistically significant for a two-tailed test at a .05 level of significance
True
Correlation does not show causation
True
Homoscedasticity is the assumption that there is an equal variance of data points dispersed along the regression line
True
If r=.25, then the coefficient of determination is .06
True
The correlation coefficient varies b/w 0 and 1 and can never be negative
false
The Phi correlation coefficient can be converted to a t statistic
true
When we compute many correlations in a single study, we report each correlation coefficient in a table called a correlation matrix
true
