- Lesson 1, Part 3: Measurement and Scale
- "Measurement" Is:
- Measurement Scales
- A Real-Number System: Order, Distance, and Origin
- Scale and Real Number System: Example
- Movie Rating Scale
- Richter Magnitude Scale: -1.5-12
- What About Richter Earthquake Severity Scale?
- Richter Scale Presented by TNT Explosions
- 1976 Tangshan Earthquake 7.8; Deaths = 240,000!
- Measurement Scales and Computation
- Variable and Score Limits
- Real Score Limits

<br />Measurement Scales and Computation<br />

- Nominal: Only one is to count
- Ordinal: No for addition, subtraction, multiplication, and division; but OK for statistical procedure based on rank;
- Interval: OK for addition and subtraction, but not multiplication and division since no absolute zero (e.g., 50 degrees is not two times 25 degrees); most of stat procedures can be used;
- Ratio: All math operations (+, -, x, /) and stat procedures (but not necessary in the meaning of a number)