Tests of association Flashcards
(28 cards)
Tests of association
refers to a number of bivariate statistcial techniques used to measure whether or not two variables are associated with each other
How are 2 interval or ration variables measured?
Person’s correlation analysis
How are 2 interval or ratio involving a DV and an IV measured?
Regression analysis
How are 2 ordinal variables measured
Spearman’s rank order correlation
How are 2 nominal variables measured
Chi - squared test
Correlation analysis
Indicates the relationship between two interval/ratio variables
Peason’s correlation coefficient
a statistcial measure of the covariation or association between two variables
coefficient of determination r2
A measure obtained by squaring the correlation coefficient, r, that proportion of the total variance of a variable that is accounted for by knowing the value of another variables
- tells us how much of an influence one variable might have upon another
correlation matrix
the standard form for reporting correlational results
What is the null hypothesis in a correlation analysis?
ρ = 0 (there is no association between the variables).
Q: What is Spearman’s rank-order correlation used for?
To measure association between ordinal variables or interval data with unequal intervals.
What is the formula for a bivariate linear regression model?
: Y = α + βX, where Y is the dependent variable and X is the independent variable.
Q: In regression analysis, what does R² indicate?
The proportion of variance in the dependent variable explained by the regression model.
Correlation
allow us to determine the direction of the association, the strength of the association and the statistcial significance of the association between 2 interval/ratio variables
Regression
Between 2 interval/ratio variables where one can be classified as the DV and the other the IV allowing us to determine association and predict values of DV based upon values of the IV
Bivariate linear regression
A measure of linear association that investigates straight line relationships of the type
What statistic is used to assess how well a regression model fits the data?
R square value
- the higher the r2, the better the model first the data and the better prediction of the dependent variable
in regression analysis, what does R² indicate?
the proportion of variance in the dependent variable explained by the regression model.
standard of error estimate
another measure of how well the model fits the dat a
What does the ANOVA F-test in regression tell us?
Whether the regression model significantly explains variation in the dependent variable.
when the significance or p value of the f statistic is > 0.05
the indendependent variables do not explain the variation in the dependent variables
when the significance or p value of the f statistic is < 0.05
the independent variables collectively do a good job in explaining the variation in the dependent variable
Why are standardised coefficients important in multiple regression?
They help determine which independent variables contribute the most to explaining the variation in the dependent variable.
What type of test is the Chi-square test for independence?
A non-parametric statistical test.
