Both interviews and experiments are research methods utilized for collecting data. An experiment is a research method used to verify whether a hypothesis about some phenomenon is valid or not. Experiments focus on the examination of causal relationship among variables. There are three main types of variables - dependent, independent, and controlled variables. Dependent variables specify what is measured, namely, what will be influeced by the experiment. For example, if we study coffee bean growth, potential dependent variables may include the number of beans, the weight of the plant, leaf surface area, etc. Independent variables are those that may affect the dependent variables. For instance, in the coffee bean growth example, potential independent variables are the amount of fertilizer, type of fertilizer, temperature, etc. Controlled variables are those whose impact on the outcome of the experiment should be eliminated. For instance, we can assume that one factor, such as temparature in the coffee bean growth example, may not make any difference towards the outcome of the experiment.
The goal of the research interview is to examine the views, experiennces, beliefs, and motivations of individuals on specific problems or phenomena. Interviews are qualitative methods which we use in order to obtain a profound comprehension of the phenomenon we are studying. There are two main types of interviews - unstructured and structured. Unstructured ( informal) interviews typically resemble a conversation because there is no predetermined set of questions. So, the participant may talk about anything he or she feels is relevant. Structured (formal) interviews, in contrast, consist of a fixed set of questions, and the interviewer maintains social distance from the participant. The advantage of an interview lies in the fact that particpants can talk openly about issues and mention important details they would normally omit in a group environment.