Wednesday, January 30, 2013
Principles of Testing and Measurements
Data Types and Why We Care
There are a million different types of data in the world. Some types we have learned through years of education and others have yet to be discovered. One question about data types that is asked frequently is “Why do we care?” Though there is no text book answer; I believe we care because without these various types of data we will not be able to answer even the simplest of questions. When I think of the definition a simple question I think of a question that can be answered in a few words. A simple question that I would like answered is “What Is Your Favorite Color?” I have picked this question because it is simple to answer and understand. My method of measurement for this question would be by ranking. For example blue would be ranked the highest because most students liked blue. I have picked basic rating because it is the best way to find the answer that I need without added confusing when it comes to understanding the results. There are many different levels of measurement. All levels have different ways numbers can be used. One level is the nominal level. At this level Numbers can be used for tags or labels like Barcodes and social security numbers. When using nominal variables measurement means is classified as classifying cases in groups. These groups “must cover all cases” and can not belong to several groups ("Levels of measurement,”). Ordinal Level is another level of measure. With this kind of measure Numbers are mostly used to order just like in popularity. You have the jerks, the cheerleaders and the Nerds but we all know what order there is. The groups for ordinal variables are ordered but the distance between two adjacent categories may vary. Interval or Ratio Level is the third level of measurement. With Interval or Ratio Levels numbers...