Measurement of scales Classifications Nominal scale Ordinal Interval

Measurement of scales

Classifications • Nominal scale • Ordinal • Interval • ratio

Nominal scale • Least powerful level of measurement • No order • No relationship • No arithmetic origin • It is a counted data • No quantitative value • Given numbers for convenience

• These numbers does not give any meaning to place them in an order • Despite its weakness…. it is widely used • E. g: Assigned numbers in the “T “shirts of cricketers

• E, g, nominal data: color of the hair, place of living, gender….

Ordinal scale • It is used commonly in qualitative research • It is a lowest level of ordered scale • Here ranks are assigned • Only ranking highest and lowest is possible • It wont tell rank one how many times better than rank 2 • Only it tells who is on the top and who is at the bottom of the scale • Comparison cannot be made • So statement one can do is… greater than and lower than

e. g. ordinal scale • Customer satisfaction survey on products • Satisfaction towards nursing care • Discomfort in the classrooms • Happiness expressed by the children

Interval scale • A rule is established to make the units equal • Here there is arbitrary zero • But no absolute zero or true zero…this is a greater limitation of this scale • It does not have a capacity to measure the complete absence of a trait hense , they are powerful than ordinal scales • Here ‘F’test , t test is generally used for statistical significance • SD is used as a measure of dispersion. • E. g for the interval scale: temperature

• Interval scales are numeric scales in which we know not only the order, but also the exact differences between the values. • E. g TEMPERATURE.

Ratio scale • Has true zero or absolute zero • zero says completely absence of measure • E. g zero length, weight, distance • Geometric and harmonic means, central of tendency and coefficient of variation are used for analysis

• These variables can be meaningfully added, subtracted, multiplied, divided (ratios).

End • The least precise scale is nominal scale • Most precise scale is ratio • As per nature of the variable the researcher need to select the scale of measurement.