This document discusses different types of measurement scales used in research: nominal, ordinal, interval, and ratio. Nominal scales involve categories with no intrinsic ordering, while ordinal scales involve ordered but non-quantified categories. Interval scales have equal intervals between points, and ratio scales have a true zero point, allowing ratios to be calculated. The type of scale used constrains the types of analysis that can be performed on the data. Questions can be designed to collect different types of data depending on the scale, from multiple choice to rankings to numerical values.