D2.1 Working with Variables.
According to Morgan et al., “Measurement is an assignment of numbers or symbols to the different characteristics of variables according to rules. In order to under your variables, it is important to know their level of measurement”. These traditional terms as different from SPSS programs, sometimes they are not always the most useful for determining what statistics to use. Nominal variable is considered the most basic of lowest level of measurement, in which the numerals assigned to each category stand for the name of the category, but they have no implied order of value. In regard to dichotomous variables, it always has only two levels or categories. In some instances, they do have particular orders, in other instances they don’t. In ordinal measurement, they are not only mutually exclusive categories as in nominal scales, but the categories are ordered from low to high. While approximately normally distributed variables not only have levels or scores that are ordered from low to high, the frequencies of the scores are approximately normally distributed. It is important to distinguish between interval and ratio data because, interval ordered levels, in which the difference between levels equal, but no true zero, while ratio ordered levels; the difference between levels is equal, and there is a true zero.