From PALS

Question 1

What is | in R

Answer 1

‘OR’

Question 2

Three types of R variables

Answer 2

Numeric
Characters (also called ‘strings”
Logical (eg true/false)

Question 3

A variable with more than one variable

Answer 3

Vector

Question 4

Character you use to select variables out of a dataframe

Answer 4

$

Question 5

Types of scores - untouched metric

Answer 5

= raw/observed

Question 6

Scaled to the metric mean

Answer 6

= Deviation scores (always sums to zero)

Question 7

Scaled to a specific mean, with specified amount of st dv per unit

Answer 7

= standardised score

Question 8

Mean is set to 0 and 1 standard deviation of 1 per unit

Answer 8

= Z score

Question 9

What are random variables

Answer 9

perpetually unknowable variables pertaining to the real world

Question 10

Two types of variable

Answer 10

Continuous (decimal points make sense)

Discrete (or factor) (ps categorical variable = discrete variables

Question 11

Standard Dev of a sampling distribution

Answer 11

= Standard error

Question 12

Examples of observed test statistic

Answer 12

t-statistic, chi-squared, F-statistic

Question 13

Theoretical probability distribution

Answer 13

gives you the equivalent of a sampling distribution without yo having to construct it

Question 14

Are CIs a function of p values

Answer 14

Yep

Question 15

What defines the CI

Answer 15

standard error + alpha criterion value

Question 16

Which error types do alpha criterions control

Answer 16

Type 1 (false positives)

Question 17

Effect size..

Answer 17

= strength of relationship

Question 18

Pearson’s r is…

Answer 18

an effect size measure

Question 19

Cramer’s V is…

Answer 19

an effect size measure

Question 20

R squared is…

Answer 20

an effect size measure

Question 21

Measuring systematic co-occurrance is done with..

Answer 21

association

Question 22

Correlation coefficient is a standardised…

Answer 22

covariance (essentially covariance of Z-scores)

Question 23

Range for Pearson’s r

Answer 23

-1 to 1

Question 24

What is r in correlation

Answer 24

sample coefficient

Question 25

What is rho in correlation

Answer 25

population parameter

Question 26

When do you use Cramer’s V

Answer 26

association between categorical variables

Question 27

Cramer’s V range

Answer 27

0-1?

Question 28

What is the value of a 0% CI

Answer 28

The sample statistic itself

Question 29

What does simple regression mean

Answer 29

1 x DV and 1 x IV

Question 30

How you calculate St Dev

Answer 30

Sort of variance

Question 31

Variance

Answer 31

Average variation

Question 32

Variation

Answer 32

Total variation…

Question 33

Covariance is standardised?

Answer 33

False

Question 34

Linear regression model equation

Answer 34

Y(hat) = a + bX + e

Question 35

What is OLS in regression

Answer 35

Ordinary Least Squares (smallest sum of squares)

Question 36

R-squared

Answer 36

proportion of variance explained by the model

Question 37

Under what conditions do you need to use an adjusted R squared

Answer 37

Small sample size

Large number of IVs

Question 38

Assumptions for regression (4)

Answer 38

1. Independence of observations
2. Linearity
3. Homoscedasticity
4. Normality of residuals

Question 39

How do you test Homoscedasticity

Answer 39

Breusch-Pagan (want a big p value)

Question 40

What is homoscedasticity anyway

Answer 40

residuals distributed equally above and below zero

Question 41

How can you tell if you’re looking at standardised multiple regression analysis results

Answer 41

there is no intercept reported (or it is 0)