Academic Insights: The Difference between Longitudinal and Cross-sectional studies.

(Askjordonltd, 2023)

Whether studying a social science or formal science, you’ll have to decide what type of study you want to conduct. Now, this decision can be made for you based on the circumstances of your project; alternatively, the study itself may dictate your goal. Let’s briefly cover what types of study fall into longitudinal and cross-sectional studies so you can determine which one fits your research need.

Cross-sectional studies

Cross-sectional studies are a popular research approach for both undergraduate and postgraduate students. The following are some of the key points to keep in mind when conducting this kind of research:

The Benefits of Cross-Sectional Studies

Cross-sectional studies can be an excellent way to gather data from multiple subjects in a short period. Unlike longitudinal studies, which track the same subjects over an extended period, cross-sectional studies involve different subjects or samples. This makes introducing new variables easier and allows modifying the experiment as needed.

For example, during a formal science study in agriculture, I was interested in examining the effects of different additives and changes in enrichment on livestock. Control groups were established in some farms where the livestock was from the same genetic stock to reduce variation.

Each farm was equipped with several sheds to accommodate the different treatments. There were control sheds with no additives or enrichment, sheds with additives, and sheds with enrichment. This setup allowed me to compare the effects of the different treatments and determine their impact on the livestock.

By conducting a cross-sectional study, I could gather data from multiple subjects relatively quickly. This approach provided valuable insights into the effects of different treatments on the livestock and helped me make informed decisions about future studies.

Cross-Sectional vs. Longitudinal Studies

During my PhD research, I conducted a cross-sectional study to investigate the experiences of multiple students over the same calendar year but within different academic years of study. My research aimed to explore the factors that affected students’ academic and personal experiences across different academic years.

Conducting a longitudinal study would have been ideal for my research, but it was not feasible for several reasons. First, I could only interview a limited number of students at a time since conducting interviews is a time-consuming process. Second, I had to speak with a certain number of students from an academic year before they advanced to their next academic year. This means I would have had to wait for each student to progress to the next academic year before I could interview them again. This would have increased the length of my study, which would have had a resource impact based on my time, which the project did not have the scope for.

Although a longitudinal study would have provided me with a more comprehensive understanding of how the factors affected the particular students’ experiences, it was beyond the scope of my PhD research and, likewise, is often the case for most other projects due to the length of time they often require. Therefore, I conducted a cross-sectional study to examine different academic years simultaneously.

The Challenges of Conducting Longitudinal Studies

The agricultural study I worked on would also be difficult to conduct as a longitudinal study. However, studies on populations such as deer could be conducted when observing population distribution, grazing habits, or behaviour based on the effect of introducing a new variable, such as a predator. These types of studies are useful for observing changes in the environment. While these types of studies could not be used longitudinally on a particular stock due to time constraints, they could be used to measure changes on progressive changes associated with a farm or system over time. This is because the experimental unit is no longer the animal or plant but the farm, site, or environment.

Specific Results of Cross-Sectional Studies

Whereas my educational project could have yielded different, more student-specific results had I used a longitudinal method. This method would not have given me the more generalised elements, such as what these interactions may have been, when they occurred, or how different individuals from various groups are affected. Now, this presents an opportunity to take the project further and grow it into a longitudinal study, taking one of these themes and looking at it specifically with an associated intervention that could then be observed over key points with possibly a smaller, more specific sample group rather than represented sample of the entire student cohort.

Conclusion

In conclusion, cross-sectional studies are a popular research approach for undergraduate and postgraduate students. They allow for a snapshot of a given sample without measuring progressive changes in the subject over time. However, it is important to remember the limitations of this type of research and when a more specific study, which looks at how interventions affect a particular group, may be better suited to the needs of your study.