At its heart and soul, market research is about measuring (counting) to establish trends — or, as I prefer to think of it, to understand the beating heart of the industry, product, etc, that you are studying.
There are three basic criteria for good measurement:
1. Reliability: The degree to which measures are free from random error and thus yield consistent results.
2. Validity: The ability of a scale (a series into which an item can be placed according to its quantification) to measure what was intended to be measured
3. Sensitivity: A measurement instrument’s ability to accurately measure variability in stimuli or responses
Basically … quantify before you qualify.