Evaluation: Quantitative Methods

To evaluate something is to examine or assess its value or usefulness. For example, many health communication experts develop messages or interventions in an effort to change an intended audience's beliefs, attitudes, and behaviors regarding an important health issue. They then implement the intervention (e.g., show it to members of the intended audience), and evaluate what effect, if any, the intervention had on these individuals. Evaluating a health communication intervention before, during, and after implementation can provide important information about the success or failure of the intervention, and help improve both the current and future interventions. Quantitative evaluation methods are those that involve the collection and statistical analysis of numerical data. Surveys and experiments are two quantitative research methods that play a very important role in the design, implementation, and evaluation of health communication messages and interventions.

Types of Survey Research

Survey research can be grouped into four main categories based on (1) whether or not the survey is completed in-person (i.e., in the researcher's presence), and (2) whether or not the survey is [Page 457]self-administered (as opposed to being administered by an interviewer). Table 1 captures the key ways survey data are collected.

Table 1 The key ways survey data are collected

The choice a researcher makes will be based on a number of factors, including the project's budget, how quickly the data are needed, how big of a sample is needed, how important it is for the researcher to be able to clarify and probe participants' responses, whether or not participants will be more comfortable giving honest answers if the survey is anonymous, and even whether or not the participants can read and write (an important consideration when studying children).