When looking at science, causation cannot be proven without well-designed experiments. An experiment in science is defined by specific characteristics that many scientific studies fall short of, though they might seem ligament. It is crucial for any individual observing or practicing science to have a solid understanding of what experimental design is, why it is essential, and where its limitations lie.
Kevin Dalby, UT Austin professor of chemical biology and medicinal chemistry, teaches at the College of Pharmacy. Dr. Dalby is highly involved in cancer drug discovery research and is studying cancer cell signaling mechanisms to develop targeted therapeutics. At the College of Pharmacy at The University of Texas, he examines the mechanisms of nature and cancer to develop new treatments and teaches and motivates students to conduct research. Being both an educator and explorer of science, Dalby understands the vitality of knowing the concept and purpose of experimental design and shares more details on the matter below.
What is Experimental Design?
Before breaking down the term experimental design, it is critical to understand the definition of an experiment. The term experiment is a study or process that results in the collection of data. An experiment’s results are not known before the experiment is conducted. An experimental design is a procedure of setting a study up or planning it out, with specific objectives in mind for the experiment to meet. The process of planning an experiment is highly vital as it helps to accurately answer the research questions that define the experiment’s objectives. An adequately prepared and planned experiment secures the correct data and suitably available sample size and power.
Good Experimental Designs Serve Three Purposes
There are three purposes an excellent experimental design serves, and those three are causation, control, and variability. Causation allows the person experimenting to create casual interferences revolving around the connection between independent variables and a dependent variable. An independent variable is essentially the “cause” factor of an experiment, which leaves the dependent variable the “effect” of the independent variable. The purpose of control gives the experimenter the ability to eliminate alternative explanations due to confounding effects of extraneous variables or variables outside of the independent variables. An experiment’s treatment conditions should reduce variability, putting forth a more straightforward task of identifying differences in treatment outcomes.
Steps to Take When Designing an Experiment
The first critical step to creating a quality experimental design is developing a hypothesis to be studied. A hypothesis serves as a starting point for an experiment and is a suggested explanation based on a platform with limited evidence to be further explored. Having a hypothesis opens the door to evaluating different options for the study’s design and defining and then reducing any biases during the experiment. An excellent experimental design also must involve a sample, resulting in the opportunity to be thoroughly designed, executed, and analyzed.
About Kevin Dalby
Kevin Dalby, UT Austin professor at the College of Pharmacy, teaches chemical biology and medicinal chemistry subjects. In addition to being a professor, Dr. Dalby specializes in cancer drug discovery research, is a co-director of the Texas Screening Alliance for Cancer Therapeutics, and is the principal investigator on a $2.3 million CPRIT grant that gives Texas scientists access to resources for drug discovery research.