Variables, Levels of Measurement and Descriptive Statistics

Question 1

Operationalise

Answer 1

making it measurable

Question 2

What level is Categorical

Answer 2

most basic level - also called nominal

Question 3

categorical

Answer 3

assigning people or things to a category normally assigned a number

Question 4

nominal numbers

Answer 4

No value - cant perform maths on them

Question 5

binary variable

Answer 5

nominal categories with only 2 possible categories

Question 6

data collected from categorical

Answer 6

frequency

Question 7

ordinal

Answer 7

ranking items - size of number/differences between numbers have no meaning - no maths

Question 8

interval

Answer 8

assume equidistant points between each of the scale

elements. eg IQ

Question 9

interval maths

Answer 9

addition and subtraction

Question 10

Ratio

Answer 10

like the interval scale in that there are equal
intervals between points on the scale.
* in addition to this the ratio scale has a true zero

Question 11

Ratio maths

Answer 11

all mathematical operations

Question 12

central tendency measures

Answer 12

mid point

Question 13

mean

Answer 13

average - “arithmetic mean”

Question 14

median

Answer 14

middle value

Question 15

mode

Answer 15

most common value

Question 16

levels of measurement mean can be applied to

Answer 16

interval and ratio only appropriate for continuous data

Question 17

levels of measurement median can be applied to

Answer 17

ordinal,interval and ratio

Question 18

levels of measurement mode is appropriate for

Answer 18

all levels

Question 19

effect of outliers: mean

Answer 19

very sensitive

Question 20

effect of outliers: median

Answer 20

insensitive

Question 21

effect of outliers: mode

Answer 21

insensitive

Question 22

outliers

Answer 22

scores that are numerically very far apart from the rest of the data you have
in a particular set

Question 23

range

Answer 23

difference between lowest and highest scores in a data set

Question 24

-ves of range

Answer 24

• only describes extreme scores
• sensitive to outliers
• tends to increase with sample size

Question 25

interquartile range

Answer 25

only looks at middle 50% of scores

Question 26

+ves of IQR

Answer 26

• It gives the central grouping of the values in a data set.

* It is the best measure of dispersion for ordinal data.

Question 27

-ves of IQR

Answer 27

• Does not use all the scores in a set in its calculation

Question 28

variance

Answer 28

based on the difference of each score from the mean of those scores

Question 29

+ves variance

Answer 29

based on every score

Question 30

-ves variance

Answer 30

obtained value is not immediately meaningful because it is not in the original units of the data (need to work out square root)

Question 31

standard deviation

Answer 31

the average deviation between a set of scores and their mean - bigger the SD = bigger spread of data

Question 32

+ves of SD

Answer 32

• based on all scores
• obtained value is meaningful in terms of the original units of the data
• best measure for interval/ratio data

Question 33

-ves of SD

Answer 33

• not meaningful for ordinal

* sensitive to extreme scores