Organisation and Presentation of Data

Data as they first arrive from a survey are raw — a heap of individual responses that, on their own, reveal very little. Before they can be analysed they must be organised and presented. This step turns scattered replies into an orderly, readable form, and it draws directly on the chapters you have already studied on classification, tabulation and the diagrammatic presentation of data.

Organising the data. Organising means classifying and tabulating the responses so that similar items are grouped together and totals become visible. Typical operations at this stage include:

• classifying observations into meaningful categories (for example, respondents grouped by income class, by age group, or by the brand they use);
• tabulating the classified data — arranging them in rows and columns with clear headings; and
• forming a frequency distribution, which shows how many observations fall into each class, so that patterns in the data begin to appear.

Presenting the data. Once tabulated, the data are made still clearer through suitable diagrams. A well-chosen diagram lets the reader grasp at a glance what a table might take much longer to convey. The book specifically mentions:

• bar diagrams, useful for comparing the sizes of different categories (for example, the number of families influenced by each advertising medium); and
• pie diagrams, useful for showing how a whole is divided into parts (for example, the share of different occupational groups among the surveyed families).

Other appropriate forms, such as histograms for continuous frequency distributions, may also be used depending on the nature of the data. …