Ch 4: Basic Statistical Concepts

Question 1

Bimodal distribution

Answer 1

A distribution with two modes

Question 2

Correlation

Answer 2

The relationship between two variables

Question 3

Correlation coefficient

Answer 3

A numerical value that expresses the degree of relationship between two variables

Question 4

Descriptive statistics

Answer 4

Statistics that describe and summarize data in a meaningful fashion

Question 5

Frequency distribution

Answer 5

Expresses how often a score occurs in a set of data

Question 6

Interval scale of measurement

Answer 6

An interval scale is one in which equal differences in scores represent equal differences in amount of the property measured but with an arbitrary zero point

Question 7

Mean

Answer 7

The arithmetical average of distribution of scores

Question 8

Measures of central tendency

Answer 8

The mean, median, and mode of a distribution of scores

Question 9

Median

Answer 9

The middle score and a distribution. It is the score that separates the top half of the test takers from the bottom half

Question 10

Mode

Answer 10

The score in the distribution that most frequently occurs

Question 11

Multimodal distribution

Answer 11

A distribution with three or more modes

Question 12

Negative correlation

Answer 12

An inverse relationship: variables are said to be negatively correlated when a high score on one is accompanied by a low score on the other. Conversely, low scores on one variable are associated with high scores on the other

Question 13

Negatively skewed distribution

Answer 13

A distribution in which more of the scores fall above the mean

Question 14

Nominal scale of measurement

Answer 14

Nominal data are categorical data. Assigning observations into various independent categories and then counting the frequency of occurrence within each of the categories creates a nominal scale

Question 15

Normal curve (bell curve)

Answer 15

In this frequency polygon, most of the scores cluster around the mean. The farther above or below the mean a score appears, the less frequently it occurs

Question 16

Normal distribution

Answer 16

Represents the way test scores would fall if a particular test is given to every single student of the same age or grade in the population for whom the test was designed

Question 17

Ordinal scale of measurement

Answer 17

Ordinal scales involve their rank order system. It is a scale in which scores indicate only relative amounts or rank order

Question 18

Positive correlation

Answer 18

A direct relationship: variables are said to be positively correlated when high score on one is accompanied by a high score on the other. Conversely, low scores on one variable are associated with low scores on the other

Question 19

Positively skewed distribution

Answer 19

A distribution in which more of the scores fall below the mean

Question 20

Range

Answer 20

The difference between the high score and the low score in the distribution (range = high score - low score)

Question 21

Ratio scale of measurement

Answer 21

A scale having interval properties except that a score of zero indicates a total absence of the quality being measured. A score of zero means zero

Question 22

Skewed distribution

Answer 22

A distribution in which the majority of scores falls at either the high end or the low end rather than the middle of a distribution

Question 23

Standard deviation

Answer 23

The spread of scores around the mean

Question 24

Variance

Answer 24

A statistical concept that tells the spread of scores within a distribution