Chapter 15
What is considered a good cronbach's alpha?
.70 is good (the higher the better)
What are considered special cases of regression?
ANOVA and t tests
What is the difference between multiple regression and hierarchal multiple regression?
In multiple regression, all the predictors are entered at the same time but in hierarchal multiple regression, the predictors are entered sequentially (the researcher decides the order of entry)
What statistical tests are mathematically equivalent variations of each other?
Independent t test, ANOVA, bivariate correlation/regression and multiple correlation/regression
What is a reliability analysis?
It measures the extent to which scores on a measure are consistent over time or are internally consistent
What are the three extensions of ANOVA?
MANOVA ANCOVA MANCOVA
What is a MANCOVA?
Multivariate analysis of covariance: assesses the relationship between nominal IVs (any number) and multiple equal interval DVs while controlling for one or more covariates.
ANOVA R^2=
Regression R^2
ANOVA SSwithin=
Regression SSerror
ANOVA SSbetween=
Regression SSregression
ANOVA SStotal=
Regression SStotal
What are these four tests all special cases of?
Th general linear model
What does the p value represent in terms of the study?
The probability of getting a t score more positive or more more negative than the t cuff off if the null is true
Why do you enter the variables sequentially in hierarchal multiple regression?
To show that one IV can account for a unique variance on the DV over and above that already accounted for by the other IV
Why do we use a partial correlation?
To sort out alternative explanations for relationships between variables
What is a special case of a one way ANOVA?
a independent t test is a special case of a one way ANOVA because it has two levels instead of three
What is a factor?
a set of items
What is a ANCOVA?
analysis of covariance: it assesses the relationship between nominal IVs (any number) and an equal interval DV while controlling for one or more covariates.
Why do we use an independent t test?
because researchers always use the simplest test because before computers, everything was done by hand
What range for a variable is considered to do a good job representing its factor?
greater than or equal to .30 or less than or equal to -.30
what is the most specialized special case?
independent samples t test
Why do we used scales than individual items to analyze?
its simpler
what is the most general special case?
multiple correlation/regression
What is a MANOVA?
multivariate analysis of variance: it assesses the relationship between nominal IVs (any number) and multiple equal interval DVs
what is a factor loading?
the association between each individual item and its factor and ranges from -1 to 1
What is a partial correlation?
the degree of association between two equal-interval variables but partialling out the influence of one or more other variables called covariates. IT is an average of multiple correlations in which a variable has been held constant.
What is cronbach's alpha?
the reliability coefficient for internal consistency of a set of items
When is factor analysis used?
to determine which variables go other with each other and which ones do not. It helps to determine which items correlate maximumly and minimally with other terms
