Measurements and Scaling
The first determination in any survey design is "What is to be measured?" Although our problem statement or research question will inform us as to the concept that is to be investigated, it often does not say anything about the measurement of that concept. Let us assume we are evaluating the sales performance of group sales representatives. We could define their success in numerical terms such as dollar value of sales or unit sales volume or total passengers. We could even express it in share of sales or share of accounts lost. But we could also measure more subjective factors such as satisfaction or performance influencers.
In conclusive research, where we rely on quantitative techniques, the objective is to express in numeric terms the difference in responses. Hence, a scale is used to represent the item being measured in the spectrum of possibilities. The values assigned in the measuring process can then be manipulated according to certain mathematical rules. There are four basic types of scales which range from least to most sophisticated for statistical analysis (this order spells the French word "noir"):