This document discusses different methods of data collection. It defines data collection as the process of systematically gathering and measuring information on variables of interest in order to answer research questions and test hypotheses. The two main types of data are qualitative and quantitative. Qualitative data is non-numerical, descriptive data often in the form of words, while quantitative data is numerical and can be mathematically computed. Common qualitative methods include interviews and focus groups, while quantitative methods include surveys, experiments, and observational studies. The document also discusses mixed methods research, which combines qualitative and quantitative approaches.