Exam 2

Question 1

Nominal #

Answer 1

may contain letters

Question 2

Ordinal #

Answer 2

rankings

Question 3

Interval #`

Answer 3

scalar

Question 4

Ratio

Answer 4

can be divided into each other to form meaningful ratios, utilizes zero.

Question 5

Normal Distribution

Answer 5

mode and mean are same as median (middle of distribution)

bell shaped - in large, fairly selected, unbiased populations

Question 6

Leptokurtic curve

Answer 6

high peaked, values centrally distributed

Question 7

platykurtic curve

Answer 7

flat, values are not centrally distributed

Question 8

bimodal/multimodal curve

Answer 8

2+ peaks, one median, 2+ modes (equal, major, minor)

Question 9

Skewed distribution

Answer 9

positive or negative (right or left)
long tail; fat tail

long tail in the positive direction - positively skewed
long tail in the negative direction- negatively skewed

Question 10

Range

Answer 10

highest score to lowest score

width of dispersement

shows variability or difference in scores

Question 11

Predictions

Answer 11

normally distributed data is commonly used as a predictor using SD
only is sample represents general population

Question 12

percentile rank

Answer 12

specific score falls within a population that has been tested or measured

equals percent of scores that are lower or equal to the specified score

always a %

Question 13

percentile

Answer 13

a particular score, on an ordered list of scores, at or below which a given percent of the other scores fall.

always given as a score, not percentage

Question 14

Z-scores

Answer 14

allows comparisons of any score to the mean by expressing as a fraction of the SD

Question 15

Z-table

Answer 15

shows percentile ranks for certain z-scores for normally distributed data

% of sample that falls to the right of the z-score

Question 16

correlations

Answer 16

degree of relationship between 2 variables

0 to 1
+ or - indicates the direction of the relationship

used to develop a prediction model

Question 17

multiple correlation

Answer 17

prediction of some variable from several more readily measured variable

Question 18

test battery

Answer 18

group of tests

Question 19

t-test and error

Answer 19

more than 3 groups increases risk of type 1 error

Question 20

type 1 error

Answer 20

inferring that a difference exists in a population then none does

Question 21

ANOVA

Answer 21

analysis of variance, use when there are 3+ variables (means)

Question 22

Probabilities

Answer 22

found with correlations

p value is the chance that random sampling would result in low correlations where the r-value may be close to zero

Question 23

type 2 error

Answer 23

fails o find a difference that really does exist

Question 24

power, define, what does it depend on?

Answer 24

ability to find the difference between the means

depends on: size of sample, size of effect, p-value, variability of the groups