Quantitative data provide information that can be counted to answer such questions as “How many?”, “Who was involved?”, “What were the outcomes?”, and “How much did it cost?” Quantitative data can be collected by surveys or questionnaires, pretests and posttests, observation, or review of existing documents and databases or by gathering clinical data. This section describes both quantitative and qualitative methods, and Table 7.1 shows examples of quantitative and qualitative questions according to stage of evaluation. These methods are rarely used alone combined, they generally provide the best overview of the project. Both methods provide important information for evaluation, and both can improve community engagement. An evaluation can use quantitative or qualitative data, and often includes both.
