Levels of measurement

What are the 3 levels of measurement?

Nominal, ordinal and interval

Nominal data

• What is it?

• Example

• Which measure of central tendency should be used for it?

• Simplest form of data, named data

• Data can be classified into discrete categories, which cannot be meaningfully ordered and do not overlap

• Frequency data- count frequency of each variable

• E.g. favourite ice cream flavour, hair colour

• Mode

interval data

• what is it

• Example

• Which measure of central tendency?

• sophisticated data

• Has units with equal and meaningful intervals (specific standardised measures)

• The values are categorical, equal and constant

• E.g. time in seconds, temperature in degrees, weight in kg

• Mean

Ordinal data

• what

• Example

• Central tendency measure

• data that can be ranked in order

• Units do not have equal intervals

• E.g Position in a Race, Scores on a Memory Test, Grades

• Median