The research design chapter discusses three main types of research designs: exploratory, descriptive, and causal. Exploratory research is used to gain background information and develop hypotheses. Descriptive research aims to describe phenomena through cross-sectional and longitudinal studies. Causal research determines cause-and-effect relationships through experiments that manipulate independent variables to measure effects on dependent variables. Test marketing is a type of field experiment used to test new products or marketing mix variations in real-world market settings.