Chapter 3 Vocab Sed 554

Front 1

Bimodal distribution

Back 1

A distribution with two modes

Front 2

Correlation

Back 2

The relationship between two variables

Front 3

Correlation coeffecient

Back 3

A numerical value that expresses the degree of relationship between two variables. Ranges from -1 to +1. -1 to 0 indicates a negative correlation and 0 to +1 indicates a positive correlation except that 0 represents no correlation whatsoever

Front 4

Descriptive Statistics

Back 4

Statistics that describe and summarize data in a meaningful fashion

Front 5

Frequency distribution

Back 5

Expresses how often a score occurs in a set of data

Front 6

Interval scale of measurement ****

Back 6

An interval scale is one in which equal differences in scores represent equal differences in amount of pthe property measured but with an arbitraty zero point. *** example: Fahrenheit scale of measurement- 20 degrees isn't twice as hot as 10 degrees and 0 does not mean there is no temperature.

Front 7

multimodal distribution

Back 7

A distribution with three or more modes

Front 8

Negative correlation

Back 8

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 (one goes up, the other goes down.)

Front 9

Negatively skewed distribution

Back 9

A distribution in which more of the scores fall above the mean than below it

Front 10

Nominal scale of measurement

Back 10

Nominal data are categorical data. Assigning observations into various independent categories and then counting the frequency of occurence within each of the categories creates a nominal scale- it has no inheirit value, it is just a label

Front 11

Normal distribution

Back 11

Represents the way the 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 (this is the goal of test makers- for scores to form a normal distribution, which follows the theoretically perfect bell curve)

Front 12

Ordinal scale of measurement

Back 12

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

Front 13

Positive correlation

Back 13

a direct relationship: variables are said to be positively correlated when a 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 ( as one goes up, the other goes up)

Front 14

Positively skewed distribution

Back 14

A distribution in which more of the scores fall below the mean than above it

Front 15

Ratio scale of measurement

Back 15

A scale having interval properties except that a score of zero indicates a total absence of the quality being measured. A scale of zero means zero. (ex distance, weight, etc)

Front 16

skewed distribution

Back 16

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

Front 17

standard deviation

Back 17

the spread of scores around the mean

Front 18

variance:

Back 18

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

Front 19

zero correlation

Back 19

no relationship between the variables, so that a change in one is not associated with a change in the other