ABSTRACT
This chapter looks at data, what they are and how they are collected. It looks at what form data exist as before they are made subject to statistical or qualitative analysis. There are data that exist as numbers and data that exist as written or spoken words. Researchers are sometimes limited to a particular level of measurement (such as ordinal) where the data only ever exist at that level. However, sometimes researchers can select data-collection tools that will yield data at a particular level of measurement. Qualitative data can be taken from interviews, manuscripts, books, drawings or really any of the many ways in which people communicate their thoughts and ideas. Questionnaires are useful and there are many occasions when they work well. However, as with any kind of data collection, one always needs to question whether there might be a better way of collecting the data. Systematic reviews often employ a ‘meta-analysis’ of data from previously published studies.
