PSY 520 Week 1 Discussion 1: [solved]
1. Nominal Scale. Nominal variables (also called categorical variables) can be placed into categories. They don’t have a numeric value and so cannot be added, subtracted, divided or multiplied. They also have no order; if they appear to have an order then you probably have ordinal variables instead.
2. Ordinal Scale. The ordinal scale contains things that you can place in order. For example, hottest to coldest, lightest to heaviest, richest to poorest. Basically, if you can rank data by 1st, 2nd, 3rd place (and so on), then you have data that’s on an ordinal scale.
3. Interval Scale. An interval scale has numbers that are ordered and have meaningful divisions. Temperatures are measured on an interval scale, which implies that a difference of 10 degrees between 90 and 100 is the same as a difference of 10 degrees between 150 and 160. When compared to high school ranking (which is ordinal), the difference between first and second place could be. 01, and between the tenth and eleventh. 5. You have something on the interval scale if you have meaningful divisions.
4. Ratio Scale. The ratio scale is exactly the same as the interval scale with one major difference: zero is meaningful. For example, a height of zero is meaningful (it means you don’t exist). Compare that to a temperature of zero, which while it exists, it doesn’t mean anything in particular (although admittedly, in the Celsius scale it’s the freezing point for water).