Decision 1: Difference Or Correlation

• Depending on type of hypothesis

Decision 2: Experimental Design

• Independent Groups = unrelated

• Repeated Measures & Matched Pairs = related

Decision 3: Levels Of Measurement

→ Interval Data

• Differences between measurements, but no true zero

• e.g. temperature in Degrees Celcius

→ Ordinal Data

• Ordered categories (rankings, order or scalings)

• e.g. service quality rating, student letter grades (differently sized gaps between each)

→ Nominal Data

• Categories (no ordering or direction)

• e.g. marital status, type of car owned