Getting to grips with Statistics: Understanding variables

What do we mean by ‘Statistics’? With an upper-case ‘S’, Statistics is the discipline of systematically analysing data that either consist of numbers or can be represented by numbers. Numerical data are collected in quantitative research studies where the aim is to investigate a research question involving counting or measuring. With a lower-case ‘s’, ‘statistics’ are quantities calculated from data values that tell you something about the data.

For example, as part of their research, Koima et al (2014) wanted to estimate the prevalence of exclusive breastfeeding among HIV-positive women in Nairobi, Kenya. They also wanted to find what factors influenced adherence to exclusive breastfeeding and to measure how strong the relationships were. Such questions can only be addressed using numerical data, which the authors collected using interviewer-administered questionnaires. The authors also collected qualitative data via interviews and focus groups to triangulate with and enrich the quantitative findings.