Chapter 13 Statistics - Organising the Data

Question 1

Raw data/scores

Answer 1

Untreated, uncovered values obtained directly from measuring process used in a study

Question 2

Categorical Variable

Answer 2

Variable where cases are merely placed into independent, separate categories

Question 3

Measured Variable

Answer 3

Variable where cases measured on it are placed on some sort of scale that has direction

Question 4

Levels of Measurement

Answer 4

Levels at which data are categorised or measured

Question 5

Nominal

Answer 5

Level of measurement at which numbers are only labels for categories

Question 6

Ordinal

Answer 6

Level of measurement at which cases are arranged in rank positions

Question 7

Interval

Answer 7

Level of measurement at which each unit on a scale represents an equal change in the variable measured

Question 8

Coding

Answer 8

Giving ‘dummy’ numbers to discrete levels of an independent variable

Question 9

Frequency data/frequencies

Answer 9

Numbers of cases in specific categories

Question 10

Quasi-Interval Scale

Answer 10

Scale that appears to be interval by where equal intervals do not necessarily measure equal amounts of the construct

Question 11

Ratio Scale

Answer 11

Interval-type scale where proportions on the scale are meaningful; usually an absolute zero exists

Question 12

Median Split Method

Answer 12

Dividing a set of measured values into two groups by dividing them into high and low at their median

Question 13

Continuous Scale/Variable

Answer 13

Scale where there are no discrete steps; theoretically, all points along the scale are meaningful

Question 14

Discrete Scale/Variable

Answer 14

Scale on which not all subdivisions are meaningful; often one where the underlying construct to be measured can only come in whole units (e.g. number of children)

Question 15

Data Set

Answer 15

Group of data points or values which can be summarised or analysed

Question 16

Central Tendency

Answer 16

Formal term for any measure of the typical or middle value in a group

Question 17

Dispersion

Answer 17

Technical and general term for any measure of the spread of values in a sample of data or population

Question 18

Mean (arithmetic)

Answer 18

Average of values found by adding them all and dividing by the number of values in the set

Question 19

Outliers

Answer 19

‘Rogue’ values at an extreme distance from the centre of the data set. Can be removed from analysis of data set because they unnecessarily distort statistics but this procedure must be openly reported.

Question 20

Trimmed Mean

Answer 20

The mean of a data set with its most extreme 5% of values removed

Question 21

Median

Answer 21

Measure of central tendency; middle value of data set

Question 22

Median position/location

Answer 22

Position where median is to be found in an ordered data set

Question 23

Class Intervals

Answer 23

Categories into which a continuous data scale can be divided in order to summarise frequencies

Question 24

Mode/Modal Value

Answer 24

Measure of central tendency - most frequent value in a data set

Question 25

Bi-modal Distribution

Answer 25

Data set with two modes

Question 26

Range

Answer 26

Measure of dispersion - top to bottom value (plus one)

Question 27

Interquartile Range

Answer 27

Distance between first and third quartile in a distribution

Question 28

Semi-Interquartile Range

Answer 28

Half the distance between first and third quartile in a distribution

Question 29

Deviation Score/Value

Answer 29

Amount by which a particular score differs from the mean of its set

Question 30

Mean Deviation

Answer 30

Measure of dispersion - mean of all absolute deviations

Question 31

Variance

Answer 31

Measure of dispersion - square of standard deviation

Question 32

Standard Deviation

Answer 32

Measure of dispersion - the square root of the sum of all squared deviations from the mean divided by N or N-1

Question 33

Uncorrected (SD)

Answer 33

Version of standard deviation or variance that is used if only wanting summary statistics for the group and not making population estimates (uses N as denominator)

Question 34

Unbiased Estimate (of SD)

Answer 34

Version of standard deviation or variance that is used for population estimates (uses N-1 as denominator)

Question 35

Degrees of Freedom

Answer 35

Common term in statistical analysis having to do with the number of individual data points that are free to vary given that overall summary values are known

Question 36

Variation Ratio

Answer 36

Measure of dispersion - proportion of non-modal values to all values

Question 37

Sample Statistic

Answer 37

Statistical measure of a sample (e.g. mean, standard deviation)

Question 38

Population Parameter

Answer 38

Statistical measure of a population (e.g. mean, standard deviation)