Statistics Test #1 Ch 1-3

Front 1

Statistics:

Back 1

methods for organizing, summarizing and interpreting data

Front 2

Sampling error

Back 2

naturally occurring difference between a statistic and a parameter

Front 3

Descreptive statistics

Back 3

organize and summarize data

take raw data and summarize it

Front 4

Inferential statistics

Back 4

use sample data to draw inferences about populations.

techniquest that allow us to study samples and make generalizations about the populations from which they were selected

Front 5

Correlational method

Back 5

two variables are observed to determine whether there is a relationship between them

Front 6

Expirimental method

Back 6

one variable is manipulated while another variable is observed and measured

Front 7

operational definition

Back 7

measurement procedure for measuring an external behaviour and uses the resulting measurements as a fefinition and a measurement of hypothetical construct.

Front 8

discrete variable

Back 8

separate, indivisible categories. No values can exist between two neighboring categories.

(gender, occupation, number of children, academic major, etc)

Front 9

Continuous variable

Back 9

infinite number of possible values that fall between any two observed values

(Height, weight, etc)

Front 10

Real limits

Back 10

the boundaries of intervals for scores that are represented on a continuous number line. The real limit separating two adjacent scores is located exactly halway between the scores. Each score has two real limits (Upper and lower)

Front 11

Nominal scale

Back 11

a set of categories that have different names.

I.e. an academic major can be chemistry or biology, but it can't be "more" chemistry than the other.

Front 12

Ordinal scale

Back 12

consists of a set of categories that are organized in an ordered sequence. Measurements on an ordinal scale rank observations in terms of size or magnitude

Front 13

Interval scale

Back 13

ordered categories that are all intervals of exactly the same size. Equal differences between numbers on scale reflect equal differences in magnitude.

like inches, seconds, points, degrees

Front 14

ratio scale

Back 14

an interval scale with the additional feature of an absolute zero point. Ratios of numbers do reflect rations of magnitude.

Front 15

X
Y
N
Sigma

Back 15

X = represent scores for a variable.
Y = second set of scores
N = numbr of scores in a population
Sigma = sum

Front 16

Frequency distribution

Back 16

an organized tabulation of the number of individuals located in each category on the scale of measurement

Front 17

Symmetrical distributions

Back 17

draw a line through the middle so that one side of the distribution is a mirror image of the other

Front 18

Skewed distributions

Back 18

scores tend to pile up toward one end of the scale and taper off gradually at the other end

^_ positive

_^ negative

Front 19

Class intervals

Back 19

Frequency distriubution table should have 10 - 15 rows. If the scores cover a wider range, it is customary to divide the range into selections called class intervals.