Speaker 1: In this video, we're going to unpack the concept of time horizon within the context of a typical dissertation, thesis, or research project. Specifically, we'll look at cross-sectional and longitudinal studies, what they are, the pros and cons, and how to choose the best option for your project. If you're currently working on a dissertation, thesis, or research project, be sure to grab our free research templates to fast-track your write-up. These tried and tested templates provide you with a detailed roadmap through each chapter, section by section. If that sounds helpful, you can find the link in the description. Alright, so let's start with the basics by first asking the question, what exactly is a time horizon? Well, time horizon, within the context of research, refers to how many times data are collected from the same participants for the same variables of interest. For example, you could survey a group of employees about their sentiment regarding management at one point in time to get a snapshot view of how they feel, or you could survey the same group before and after a change of management to assess how their sentiment shifted. When you collect data at only one point in time, we call that a cross-sectional time horizon, or a cross-sectional study. Conversely, when you collect data more than once for the same sample regarding the same variables of interest, we call that a longitudinal study. Importantly, for a study to be longitudinal, you need to collect data from the same sample regarding the same variables of interest. If for example you collected data at two points in time from the same sample, but each time it was about a different topic of variables of interest, that would still be cross-sectional in terms of approach. So let's look at the pros and cons of each approach. Cross-sectional studies have a few distinct advantages over longitudinal ones. Most notably, they're relatively quick and cost-effective, as you only have to collect the data once. This also means that, for the same amount of effort, you can gather twice the sample size of what you would have in a longitudinal study. As a result, you can have higher confidence in the point estimates that you generate. Now of course, it's not all roses for cross-sectional studies. Given their nature, they only provide a static view, a snapshot in time, of the variables of interest. This also makes them quite sensitive for timing. For example, sticking with the study that I mentioned earlier, if you happen to survey employees regarding their feelings about management in the same week that management had to deliver some bad news about layoffs, you might get a somewhat skewed measurement. Longitudinal studies, of course, also have their strengths and weaknesses. They're less sensitive to timing than their cross-sectional counterparts, and because they involve collecting data at multiple points in time from the same respondents, they allow you to identify emergent patterns across time that you'd never see if you used a cross-sectional approach. Longitudinal studies also reveal the order in which things happened, which helps a lot when you're trying to understand causality. Of course, this all comes at a cost. Longitudinal studies are naturally more resource and time intensive, and depending on the timeline, you might run into data access issues if some of your respondents opt out over the period of the study. Also, their inherent lengthiness might make them impractical for projects with a short timeline. For example, undergraduate or master level research projects. So you have to keep these practicalities in mind. If you're enjoying this video so far, please help us out by hitting that like button. You can also subscribe for loads of plain language, actionable advice covering all things research related. If you're new to research, check out our free dissertation writing course, which covers everything you need to get started on your dissertation, thesis, or research project. Links in the description. Alright, so now that we've covered the cross-sectional and longitudinal approaches, the golden question is, of course, which one should I use? Ideally, your choice of time horizon should be determined by your research aims, objectives, and research questions. In other words, your golden thread should heavily influence this research design choice, much like all the other methodological choices. By the way, you can learn more about the golden thread in this video. To demonstrate this, let's look at an example. If your research aims involved assessing how attitudes towards something change over a period of time, a longitudinal study would generally be a good fit. Conversely, if your research aims were interested in the current attitudes towards something, a cross-sectional approach would likely be the best choice. So as you can see, it's about adopting a time horizon that aligns with your broader research aims, or using the most suitable tool for the job. If you are leaning toward a longitudinal time horizon, it's important to keep the practicalities in mind. Frequently, there just isn't enough time for a longitudinal study that spans months or even years. Similarly, you might not have the resources to pull off multiple surveys or rounds of interviews in multiple locations. Simply put, there's a tradeoff between the ideal research design and the practical one. That said, don't make the mistake of thinking a cross-sectional time horizon is inferior and can't result in a high-quality research project. Each approach has its place. What's important is that your choice of time horizon aligns with your research aims, objectives, and research questions, and is practical given your constraints. If you enjoyed the video, please hit that like button to help us reach more students. For more videos like this one, check out the Grad Coach channel, and subscribe for plain language actionable research advice. Also, if you're looking for one-on-one support with your dissertation, thesis, or research project, be sure to check out our private coaching service, where we hold your hand throughout the research process, step-by-step. You can learn more about that and book a free initial consultation at gradcoach.com.