A Guide to the Four Quantitative Research Designs
So, you’ve elected to undertake a quantitative study for your doctoral dissertation, what’s next? An important element of your research project is to select your research design. Your choice of research design should be guided by your research questions. Selecting the appropriate research design is essential to ensure that the data you collect can be used in a meaningful way. Your choice of research design will have bearing on every aspect of your research plan including your study sample, statistical analyses, and the presentation of your results. Let’s look at an overview of the four main quantitative research designs:
Descriptive
A descriptive design is aimed at giving an accurate representation of circumstances, elements, or occurrences. It can inform the researcher as to the where, what, and when but the results cannot extend beyond the study sample. A descriptive design does not seek to determine whether relationships are present between variables, but rather to describe the distribution of variables within your study sample. This method of research is purely based on observing, recording, and quantifying the variables of interest.
Examples of questions that can be answered using a descriptive research design:
- What is the overall level of job satisfaction and remuneration of employees at Company X?.
- How many negative online reviews has Restaurant X received since 2015? How many table bookings have been lost since 2015?.
- How many celebrity endorsements did Product X receive over the last two years? How many sales of Product X have there been over the last two years?
Correlational
A correlational design compares two or more variables and/or investigates how they relate to each other. The researcher does not influence, control or manipulate the variables of interest, and therefore cannot assign cause and effect. Remember the golden rule: Correlation does not imply causation. For an interesting, short read on the topic, I recommend “Correlation and Causation: A Comment” by Stephen Stigler (Stigler, 2005).
Examples of questions that can be answered using a correlational research design:
- Is there a relationship between an employee’s job satisfaction and their remuneration package?
- Is there a relationship between a restaurant’s negative online reviews and the number of table bookings they receive?
- Is there a relationship between the celebrity endorsements of skincare products and the number of product sales?
Quasi-Experimental
Similar to a true experimental design, a quasi-experimental design type seeks to establish a causal relationship between an independent and dependent variable. A quasi-experimental design can rely on either random or non-random assignment, however, unlike a true experiment, there are often confounding variables that cannot be accounted for within the research design. This type of design is a convenient substitute in situations where ethical or practical circumstances prevent a true experiment.
Examples of questions that can be answered using a quasi-experimental research design:
- Does a specific wellness intervention have a significant impact on employee job satisfaction?
- Does the implementation of online review platforms have an impact on the number of table bookings a restaurant receives?
True Experimental
An experimental design is characterized by a completely controlled environment. The researcher has control over all study variables which are manipulated to systematically test a specific theory or theories. The aim of an experimental research design is to establish a cause-and-effect relationship. To successfully run an experimental quantitative study, you need to have an in-depth understanding of the topic in question, a testable theory, and planned experimental manipulations of your independent variable.
Examples of questions that can be answered using a true experimental research design:
- What is the effect of acid levels in soil on tomato fruit production (assessed within a laboratory).
- What is the effect of increasing the ratio of aluminum to corrosion within Metal Product X?
Final thoughts
If you are looking for guidance on which design type is most appropriate to address your research questions, contact us to book your complimentary consultation and let us see how we can assist you on your road to a successful dissertation.
Reference:
Stigler, S.M. (2005). Correlation and Causation: A Comment. Perspectives in Biology and Medicine 48(1), 88-S94. doi:10.1353/pbm.2005.0045.