Levels of measurement. Scaling data and standard scores
Descriptive and inferential statistics
The normal distribution. Probability and significance testing
Our investigation of analytical techniques is now ready to move from qualitative analysis to quantitative. Qualitative techniques, as we have seen, are approaches to data analysis which focus on the meanings of the information which has been received, and which attempt to draw out those meanings as part of the analytical process. Quantitative techniques, by contrast, are methods of analysis which involve the manipulation of numerical data and, at least in psychology, very often include calculations of probability.
The form of analysis that we use is closely linked with the research method that we have used to collect the data in the first place. We have looked at a variety of different methods of gathering information. Some of these, such as laboratory experiments and observations, are very tightly controlled, and limited in the number of possible outcomes which they allow. The information they give us, too, is very clearly defined and specific. Other research methods, such as interviewing or field observations, are more open to outside influences, and the information that they provide is more variable and unpredictable. Table 14.1 lists a number of different types of information that we might want to discover as part of a psychological research project. It isn't an exhaustive list, but it does give an idea of the range. In each case, some research methods would be appropriate for gathering that type of information, while others would not.