Stats Exam #1

Question 1

Definition of statistics

Answer 1

A set of tools and techniques that are used for describing, organizing, and interpreting data

Question 2

Descriptive statistics

Answer 2

Used to organize and describe the characteristics of a given data set

Question 3

Inferential statistics

Answer 3

Used to make inferences based on a smaller group of representative data

Question 4

Data set

Answer 4

A collection of data

Question 5

Population

Answer 5

All of the occurrences within a certain characteristic

Question 6

Sample

Answer 6

A subset of a population

Question 7

Empirical evidence

Answer 7

Information obtained through observation

Question 8

Three measures of central tendency

Answer 8

Mean, median, and mode

Question 9

Mean

Answer 9

The average, used when there are no outliers or categories

Question 10

Median

Answer 10

The middle value, used when there are outliers

Question 11

Mode

Answer 11

The most common value, used with categories of data

Question 12

Σ (Sigma)

Answer 12

Add together whatever follows it

Question 13

x

Answer 13

Each individual score in the group

Question 14

n (italicized)

Answer 14

The sample size

Question 15

N

Answer 15

The population size

Question 16

What do higher and lower scores do to the mean?

Answer 16

Skew it

Question 17

Three measures of variability

Answer 17

Range, standard deviation, and variance

Question 18

Range

Answer 18

The distance between the biggest and smallest scores

Question 19

Standard deviation

Answer 19

The average amount of variability in a data set

Question 20

Variance

Answer 20

The standard deviation squared

Question 21

Bar graph

Answer 21

Compares frequency

Question 22

Line graph

Answer 22

Trend of data over time

Question 23

Pie graph

Answer 23

Percentage that a category takes up out of the whole

Question 24

Scatterplot

Answer 24

Shows the relationship between two variables

Question 25

Histogram

Answer 25

Shows the center and spread of the data, as well as outliers and skewness

Question 26

Correlation

Answer 26

The relationship between two variables

Question 27

Pearson product-moment correlation

Answer 27

Examines the relationship between two continuous variables

Question 28

Direct correlation

Answer 28

The variables change in the same direction

Question 29

Indirect correlation

Answer 29

The variables change in different directions

Question 30

Positive slope

Answer 30

The line on the scatterplot goes up from left to right

Question 31

Negative slope

Answer 31

The line on the scatterplot goes down from left to right

Question 32

.5 - 1.0

Answer 32

Strong

Question 33

.3-.4

Answer 33

Moderate

Question 34

0-.2

Answer 34

Weak

Question 35

Coefficient of determination

Answer 35

Square the correlation coefficient

Question 36

Coefficient of alienation

Answer 36

The percent that remains after the coefficient of determination

Question 37

Validity

Answer 37

Does it test what is claims to test?

Question 38

Reliability

Answer 38

Does it test the same coinsistently?

Question 39

Independent variable

Answer 39

The manipulated variable

Question 40

Dependent variable

Answer 40

The measured variable

Question 41

Common types of validity

Answer 41

Content, criterion, and construct

Question 42

Content validity

Answer 42

Does the content cover all of the aspects of the topic?

Question 43

Criterion validity

Answer 43

Do the scores relate to other criteria that measure the same thing?

Question 44

Construct validity

Answer 44

Does the test measure some underlying psychological construct?

Question 45

Concurrent validity

Answer 45

Consistent with the present

Question 46

Predictive validity

Answer 46

Consistent with the future

Question 47

Four types of validity

Answer 47

Test-retest, parallel-forms, inter-rater, and internal consistency

Question 48

Test-retest

Answer 48

Is the test reliable over time?

Question 49

Parallel forms

Answer 49

Are different forms of the test reliable or equivalent?

Question 50

Inter-rater

Answer 50

Is there consistency among different people who score the same?

Question 51

Internal consistency

Answer 51

Is there consistency in the scores among the items on the test?

Question 52

True score

Answer 52

The score you would get if you took the test an infinite number of times

Question 53

Observed score

Answer 53

What you got on the test once

Question 54

Null hypothesis

Answer 54

There is equality among the variables, considered to be true without knowing more

Question 55

Research hypothesis

Answer 55

The variables are inequal, there is statistical significance