Most quantitative dissertations, whether carried out by academics or undergraduate, master's or doctoral level students, will involve one of three types of replication, which we refer to as duplication, generalisation or extension.
In most cases, replication is associated with duplication. In other words, you take a piece of published research and repeat it, typically in an identical way to see if the results that you obtain are the same as the original authors. In some cases, you don't even redo the previous study, but simply request the original data that was collected, and reanalyse it to check that the original authors were accurate in their analysis techniques. However, duplication is a very narrow view of replication, and is partly what has led some journal editors to shy away from accepting replication studies into their journals. The reality is that most research, whether completed by academics or dissertation students at the undergraduate, master's or doctoral level, involves either generalisation or extension. This may simply be replicating a piece of research to determine whether the findings are generalizable within a different population or setting/context, or across treatment conditions; terms we explain in more detail later in this article. Alternately, replication can involve extending existing research to take into account new research designs, methods and measurement procedures, and data analysis techniques. As a result, we call these different types of replication study: Route A: Duplication, Route B: Generalisation and Route C: Extension.
In reality, it doesn't matter what you call them. We simply give them these names because (a) they reflect three different routes that you can follow when doing a replication-based dissertation (i.e., Route A: Duplication, Route B: Generalisation and Route C: Extension), and (b) the things you need to think about when doing your dissertation differ somewhat depending on which of these routes you choose to follow. However, it's worth noting that these three routes are not mutually exclusive, which means that your dissertation could either (a) incorporate elements of all three types or (b) simply follow one of these three routes. For the most part, you'll take on just one route.
The purpose of this article is to help you select which of these three routes you will take on. In Step One: Learn about Route A: Duplication, Route B: Generalisation and Route C: Extension, we explain what each of the three routes is and what it involves. In Step Two: Justify taking on a replication-based dissertation, we help you to justify taking on a replication-based dissertation, since this is an inevitable step in getting your topic approved. In Step Three: Determine whether a replication-based dissertation is right for you, we highlight some of the benefits and challenges of taking on a replication-based dissertation so that you know what to expect. Finally, in Step Four: Learn how Lærd Dissertation can help, we point to the various sections of this site where we help walk you doing a dissertation based on Route A: Duplication, Route B: Generalisation or Route C: Extension.