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PDAM #6
| Question | Answer |
|---|---|
| What is Factorial ANOVA (2) | 1, it involves two or more independent variables 2, it is good to see if whenever one independent variable depend on anothe independent variable INTERACTION EFFECT |
| What are assumptions for Factorial ANOVA (2) | 1, independent measures 2, independent & normally distributed error/ residual (again robust for homogeneity) |
| In calculation of Factorial ANOVA what is different (2) | 1, SSm is splitted into multiple categories for each group and group interaction 2, that leds to multiple F-test and ost-hoc outputs |
| What is Covariance (2) | 1, Cov(x,y) = ∑(x-x̄)(y-ȳ) / n-1 2, shows how scores on two variables differ from their means, on average |
| What is standartized covariance | Correlation coefficient r= Cov(x,y,) / Sx*Sy |
| What is "phylosifically" our goal when comparing F models | if F models are more reliable methods that just mean |
| What is R² (3) | 1, shared variance 2, coefficient of determination 3, Correlation squared 2 |
| What are 3 methods to calculated correlation if there is no normality | 1, Bootstrap CI 2,Spearman r 3,Kendall´s tau |
| How does Kendall´s tau works (3) | 1, check concordant and discordant pairs 2, how often higher (or lower) x correspond to higher (or lower) y 3, values from -1=perfect negative 0= no effect 1= higher possible effect |
| How does Spearman works (4) | 1, rank x and y 2, check how different the rank positions are 3, values -1 to 1 where 0= no relation 4, sensitive to outliers and errors |
| What is idea between partial correlation (2) | 1, there may be another variables affecting the relationship investigated 2, with partial correlation the correlation is adjusted for that effect |
| What is standartized beta in simple regression | it is the same as r (unsquared explanatory level) >> β = r |
| What is important to check before using model for validity & generalizability (2) | 1, are the 4 assumption for linear regression met 2, would change excluding certain cases result in different regression coefficient |
| What 3 types of methods of including multiple predictors in regression are there | 1, Enter / forced entry 2, Hierarchial / blockwise 3, Stepwise methods |
| What is 1, Enter / forces entry method 2, Hierarchial / blockwise method | 1, Enter / forces entry method >>> all predictors are entered simultaneously 2, Hierarchial / blockwise method >>> researcher decides the order in which variables are entered into the model |
| Which 3 stepwise methods of including multiple predictors in regression are there | 1, Forward 2, Stepwise 3,Backward |
| How do following stepwise methods work 1, Forward 2, Stepwise 3,Backward | 1,Forward >adding predictors one by one starting with the one with strongest significance 2,Stepwise >adding the best predictor and add another if it improve the model 3,Backward >starting with all predictors and one by one exclude the weakest |
| What happens if we violate assumptions of regression model | we decrease confidence of the validity and the generalizability |