Variables

Question 1

2 key distinction of variables:

Answer 1

• LEVEL OF MEASUREMENT

- CONTINUOUS/DISCRETE

Question 2

Level of measurement = 3 variables:

Answer 2

NOMINAL
ORDINAL
INTERVAL/RATIO

Question 3

Level of measurement/scale of measurement of a variable that indicates:

Answer 3

how much information the number contains

Question 4

Nominal =

Answer 4

• numbers used to code information
• e.g. continent: 1 = AFRICA, 2 = ASIA
• values aren’t ordered in relation to each other
• distance also meaningless, e.g. can’t calculate ‘average continent’
• UNORDERED CATEGORIES

Question 5

Ordinal =

Answer 5

• ORDERED CATEGORIES, e.g. income group: 1 = low, 2 = middle, 3 =high
• Order of number is meaningful, e.g. a country’s income is higher than another’s
• Distances between values have no meaning - CANNOT SAY HOW MUCH HIGHER
• Cannot sensibly, e.g. calculate average income

Question 6

Interval/ratio =

Answer 6

• Order of numbers is meaningful
• e.g. a country’s income is higher than another’s
• Distances between values = meaning = compare
• Can sensibly, e.g. calculate average income

Question 7

CONTINUOUS/DISCRETE: In practice, variables that have many values =

Answer 7

continuous

-variables that have only a few values = discrete

Question 8

Discrete =

Answer 8

CATEGORICAL
-Basic unit of measurement cannot be subdivided
-e.g. Income in categories: low,middle,high
-e.g. Days
-e.g. Did you study at all last week?
: YES/NO = DICHOTOMOUS/BINARY VARIABLE

Question 9

DICHOTOMOUS/BINARY VARIABLE =

Answer 9

just 2 categories, e.g. yes/no

Question 10

Continuous =

Answer 10

• if it can in principle be subdivided without limit
• e.g. income measured in dollars, fractions of dollars
• e.g. time [hours, minutes, seconds]

Question 11

Variables relationship can also be:

Answer 11

SPURIOUS

INTERVENING

Question 12

Spurious relationship : there is neither a direct nor indirect pathway between variables e.g. between shoe size and gender

Answer 12

ADULTHOOD       
       /                              \
SHOE       --------->    INCOME
SIZE         
       \                              /
               GENDER

Question 13

Intervening relationship: a variable intervenes between 2 other variables causing an INDIRECT RELATIONSHIP

There is also a direct relationship between 2 variables

Answer 13

(indirect relationship)
PART-TIME WORK
/ \
/ \
GENDER ———–> SUPERVISORY
(direct relationship) POWER

Question 14

Measurements are used sometimes as:

Answer 14

performance indicators

Question 15

Performance indicators: often measurements are motivated by the aim of

Answer 15

improving something

Question 16

Performance indicators: many are used to

Answer 16

track performance

Question 17

Performance indicators: GOODHART’S LAW: any measurements identified as targets become:

Answer 17

useless as measurements

Question 18

CONTINUOUS VARIABLE: use a threshold to divide it into a categorical one with 2 categories creates an:

Answer 18

ABSOLUTE LEVEL

Question 19

CONTINUOS/DISCRETE: definition as relative, recoding from continuous to categorical creates a:

Answer 19

relative threshold: can move up/down

Question 20

BOTH CONTINUOUS/DISCRETE PRODUCE:

Answer 20

COMPOSITE INDICATORS/SCALES