A research design is selected based on the scientific method. If the researcher knows little about the topic of interest, then an exploratory design is the best approach. Exploratory designs are discovery oriented. Descriptive research is designed to obtain data that describes the characteristics of the topic of interest. If a researcher wants to develop frequencies of certain variables or describe basic relationships, a descriptive design is probably appropriate. If the researcher is interested in testing whether one variable causes another, then a causal design should be used.