Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
Definition of Wald Test |
Joint Significance test for non-metric variables with more than 1 group |
|
What test do you use when there are non-metric variables with 2 variables
|
t-test |
|
What test do you use when there are non-metric variables with more than 2 variables? |
Wald-test |
|
What assumption does Homoskedasticity have? |
Equal variance with groups |
|
From the output, what needs to be read to check for Homoskedasticity?
|
Standard Error & p-value |
|
What is the Wald-test used for? |
Correction for Wald-test |
|
How do you interpret this equation? |
One unit in x1 means, holding the other variables in the model constant, an expected increase of B1 units in y |
|
Factors are interval scales, therefore? |
No absolute zero |
|
What does 1 unit (standard deviation) increase mean in a factor? |
A Standard deviation is a "typical deviation of an observation from its mean" |
|
How can the coefficients be interpreted
|
if B1 > B2, then x1 is more important than x2 |
|
What are the three steps to interpreting coefficients? |
Significance Direction Magnitude |
|
What is moderation?
|
The interaction
|
|
What does a negative significance suggest? e.g. Log(starpower)*log(Adspend) |
Advertising is less effective for movies with more powerful stars |
|
How can 0/1 variables be explained? |
Either yes or no. Bankrupt or not |
|
What are the problems with the Linear Probability Model? |
Fitted probabilities can be >1 or <0. Non linear relationships |
|
What is the formula? |
Odds Ratio |
|
How is this interpreted? |
For every newspaper that someone reads, the odds of being in favor of legalizing abortion increases by a factor of 1.497 |
|
How is this interpreted? |
The odds of a republican being in favor is only 0.004 times the odd of a democratic being in favor of legalizing abortion - holding media consumption through newspapers constant |
|
How is this interpreted? |
The odds of a republican being in favor is only 0.003 the odds of a democratic being in favor of legalizing abortion - holding gender and media consumption through TV and Newspaper constant |
|
What methods can be used for Model Fit? |
AIC. Hit Rate |
|
How is the AIC interpreted
|
The probability that we observe what we observe together with the number of parameters in the model (penalized for more parameters)
|
|
What value is desired for AIC |
the lower the better |
|
What needs to be considered when using the AIC? |
AIC can only be interpreted relatively in comparison to other models |
|
How is the Hit-rate computed? |
Compute Fitted Probabilities Create Best Guess (Assign 1 for >0.5, 0 for <0.5) Compare best guesses data |
|
What is the True Positive Rate? |
Sum of positives matching the 1 |
|
What is the True Negative Rate? |
Sum of positives matching the 0 |