Research is broadly divided into two categories: qualitative and quantitative. Within each of those categories are multiple designs and methods. Among the quantitative methodologies are non-experimental designs.

Non- experimental designs differ from experimental designs in the fact that there is no manipulation of the circumstances; that is there is no treatment or condition change.  The College of Doctoral Studies at GCU has approved two non-experimental designs. These are the descriptive-regression model and the descriptive-causal-comparative model. Studies using descriptive types of research design are attempting to use statistical analysis to summarize a sample set of data in order to determine if there is a relationship between the variables.

Descriptive-regression models attempt to fit a linear curve (straight line) to a scatter plot of the data collected to determine if a relationship exists between the dependent and independent variables. This design is effective when the researcher wants to predict one or more values of the dependent variable from values of the independent variable. The statistical tests performed include linear regression, multiple regression, and non-parametric statistical tests.

Descriptive-comparative designs are used to compare two or more groups. Ccomparative designs are often employed after the effects are observed. For example, a teacher observing a phenomenon in the classroom or a business person noticing a phenomenon in the retail sales environment may conduct a comparative study to determine the reasons for the observed phenomenon. These post-effect observations lead researches toward the potential reasons for the observed effects. The most common statistical tests performed include the independent-sample t-test, the one-way analysis of variance (ANOVA), the chi-square test, and non-parametric statistical tests.

Non-experimental design is but one form of research design that is suitable and meaningful for dissertation research. Additional designs will be reviewed later in this series. In all cases, doctoral learners are advised to have relevant conversations with their dissertation committee and their methodologist and chair in particular to determine the best design to address the research questions of the proposed dissertation study.