Statistics and Distributions

Question 1

measures of dispersion

Answer 1

descriptive statistics

how tightly clustered are individual data points to the mean

Question 2

variance

Answer 2

descriptive statistics
difference between each data point and mean
square each value
divide sum by (n-1)

Question 3

Standard deviation

Answer 3

the square root of the variance

the extent of deviation for a group as a whole

Question 4

probability distributions of a discrete variable

Answer 4

identifies the probability of each value

Question 5

probability distributions of a continuous variable

Answer 5

identifies the probability of the value falling within a particular interval

Question 6

all probability distributions add up to ____

Answer 6

1 or 100

Question 7

percentile

Answer 7

1% cut off

Question 8

decile

Answer 8

10% cut off

Question 9

tertile

Answer 9

1/3 cut off

Question 10

quartile

Answer 10

1/4 cut off

Question 11

quantile

Answer 11

1/5 cut off

Question 12

positive skew

Answer 12

heavy right tail

Question 13

negative skew

Answer 13

heavy left tail

Question 14

are +/- 1 SD away from mean

Answer 14

68%

Question 15

area +/- 2 SD away from mean

Answer 15

95%

Question 16

are +/- 3 SD away from mean

Answer 16

99.7%

Question 17

mean IQ is

Answer 17

100

Question 18

z score is

Answer 18

number of SDs away from the mean

Question 19

conceptual hypothesis

Answer 19

texts that concern a topic familiar to a reader are easier to comprehend

Question 20

research hypothesis

Answer 20

operationalizes conceptual hypothesis

Question 21

statistical hypothesis

Answer 21

whether selected hypothesis about whether selected parameters of data population are are equal or different

Question 22

null hypothesis

Answer 22

baseline, statement of equality

Question 23

alternative hypothesis

Answer 23

statement of inequality typically what you are trying to prove

Question 24

we use _______ to test the null hypothesis

Answer 24

inferential statistics

Question 25

to prove null hypothesis is wrong we just need to prove that _______ is right

Answer 25

alternative

Question 26

statistically significant p=___

Answer 26

0.05 or 0.01

Question 27

t test

Answer 27

evaluation of difference between 2 variables relative to variability in the data

Question 28

f test

Answer 28

used to compare means of more than 2 groups, compares between group variability with within group variability

Question 29

Inferential outcomes: correct

Answer 29

reject null hypothesis which is in agreement with true population value

Question 30

Inferential outcomes: false positive, type 1 error

Answer 30

reject null hypothesis when there is no true effect

Question 31

Inferential outcomes: power

Answer 31

do not reject null hypothesis and rightly so

Question 32

Inferential outcomes: false negative, type 2 error

Answer 32

we do not reject null hypothesis when there is an effect truly there

Question 33

ho do we decrease type 1 errors

Answer 33

by moving judgment criteria

Question 34

is 1 SD from mean enough to be signifigant

Answer 34

No

Question 35

inferential tests

Answer 35

estimate how certain we are about rejecting the null hypothesis

Question 36

standard error

Answer 36

how close mean of sample is to true population mean | like the SD of inferential statistics

Question 37

increase power by ... (3)

Answer 37

increase sample to decrease standard error make signifigant threshold less strict make data less variable

Question 38

participation observation

Answer 38

enter the world of people

Question 39

laboratory observation

Answer 39

controlled lab

Question 40

interviewing

Answer 40

honest answers? intimidating get direct info

Question 41

phone interview

Answer 41

no travel | selection bias

Question 42

quesstionares

Answer 42

cheap and fast

Question 43

perfect correlation

Answer 43

correlation of 1 or -1

Question 44

semipartial correlation

Answer 44

a measurement of the correlation between 2 variables that remains after controlling for the effects of 1 or more predictor variables

Question 45

standard score

Answer 45

(individual score-mean score) / SD

Question 46

r^2

Answer 46

squaring correlation coefficient of determination calculates effect for correlations indicates proportion of variance

Question 47

eta squared

Answer 47

proportion of the total variability of the DV that is accounted for by the IV

Question 48

cramers Φ

Answer 48

chi squared test for independence with 2 rows and 2 columns

Question 49

cramers v

Answer 49

chi squared for larger than 2x2

Question 50

cohens w

Answer 50

chi-squared goodness of fit

Question 51

cohens d

Answer 51

effect size calculation that looks at the difference between the means of two groups and takes into account the variability using the pooled sample standard deviation