STEP ONE

Understand the three routes you could pursue
Duplication, Generalisation or Extension

Before you start to assess the article you are interested in, we would recommend that you broadly understand what the three routes are. This will help you when you are assessing the potential of your main journal article. By potential, we mean (a) which of the three routes are available to you, and (b) what specific aspects of these routes it is possible to follow. Ultimately, when you carry out a replication-based dissertation, you will most likely settle on a particular route, at least at the undergraduate and master's level. If you can't remember the main characteristics of these three routes, we explained them in the introductory article to replication-based dissertations: Route #1: Getting started. It is worth re-reading this introductory article before moving on.

STEP TWO

Consider how to choose a route
Personal interest, academic justifications, and deal breakers!

Broadly speaking, deciding what route to follow comes down to balancing your (a) personal interests, (b) academic justifications, and (c) deal breakers:

Personal interests

To say that personal interests can determine (a) the route that you take, and (b) the specific approach that you take within that given route, is not particularly academic, but it is inevitable that this will play a role. For example, you may be interested in the findings of the original study, but not the population or setting/context where the study was conducted. Your interests may lie in a different population or setting/context. Whilst it is useful from an academic perspective to have a justification for replicating a study in a different population or setting/context, perhaps because you feel that there is a good reason why this different population or setting/context would yield different results, it can also be useful to simply see how far an original study generalises (i.e., by testing a wider range of different populations or settings/context, even if you are not sure why these might yield different results). You also have to ask yourself what you want to achieve from your dissertation. Are you looking to take on as much as possible and push yourself, aiming for a high mark, or simply get a pass or good pass, in which case you are less likely to take on Route C: Extension, for example, which is more involved than Route A: Duplication, and even Route B: Generalisation.

Academic justifications

Whilst personal interests take you so far, it is important to have good academic reasons not only to (a) justify the route that you adopt, but also (b) the specific justifications for taking different approaches within a given route. For example, when taking on Route B: Generalisation, there are four broad types of generalisation: across populations, settings/contexts, treatments and time. The justification behind each of these types of generalisation will be different, not only in general, but based on the specifics of the main journal article you are interested in. We come back to academic justifications shortly.

Deal breakers!

You may be interested in a particular journal article, or even have a few potential journal articles still on your list, but there are deal breakers to every replication-based dissertation that will question whether you should simply move onto another journal article rather than spending more time pursuing the ones you are currently considering. These deal breakers include whether: (a) the data you need is accessible; (b) the research strategy of the original study is clearly set out, and the measurement procedure is accessible; and (c) you have, or could develop, the required data analysis skills in time. Each of these deal breakers is discussed below:

• The data you need is accessible

  If you are considering Route A: Duplication, you have to ask yourself if you can get hold of the original data. If not, you need to think about whether you can you get access to a similar sample and population. If neither of these options is available, we would suggest you move onto another journal article. Whilst there is more flexibility when it comes to the data you need to access for Route B: Combining and Route C: Extension, you will need to make sure that you will be able to get access to such data. Since gaining access to data can be one of the most difficult stages of dissertations, irrespective of the type of quantitative dissertation you take on, having easy (or relatively easy) access to data is important.

• The research strategy of the original study is clearly set out, and the measurement procedure is accessible

  You can't easily replicate a study if you don't know how the authors carried out their research; in other words, what research strategy they followed. By research strategy, we mean everything from the research design that was used, right through to the sampling strategy that was followed, the research methods, measurement procedures and measures that were adopted, as well as the data analysis techniques that were carried out. We explain all about research strategies and their components later. For now, just think of it in a simple way: If the authors used a questionnaire, and the journal article does not include the questionnaire (i.e., the actual questions that were used and the measures for each of these questions), how can you duplicate the research? In such an instance, if the authors cannot (or will not) give you access to this questionnaire, you will not be able to pursue Route A: Duplication. You may still be able to take on Route B: Generalisation in those instances when the measurement procedure, when applied to study another population or setting/context is significantly different than the original, but there are few instances where this is the case, or where such changes are not made based on knowledge of the original measurement procedure. Only in the case of Route C: Extension, where you adopt many of the goals of the study you are replicating, but have more freedom in terms of your selected research strategy and measurement procedure, this not a deal breaker. Therefore, if you are interested in pursuing Route A: Duplication or Route B: Generalisation, ask yourself: Is the research strategy of the original study clearly set out, and most importantly, is the original measurement procedure set out in the journal article, or available from the authors? If the answer is NO, we would recommend that you move onto another journal article.

• You have, or could develop, the required data analysis skills in time

  There are a broad number of skills you need when carrying out a replication-based dissertation, but the core skills that can become a deal breaker are data analysis skills. It is not so much that you cannot learn these skills, or that we do not provide extensive guides in the Data Analysis section of the site, but that it takes time to develop and apply these skills. You should be able to develop most of these skills in time, but if the journal article you are looking at used complex statistical tests (e.g., structural equation modelling, partial least squares, etc.), you may need to try and use less complex alternatives in your dissertation, or choose another journal article that used less complex tests in the first place.

Think about these three issues - (a) data accessibility, (b) a clearly set out research strategy and accessible measurement procedure, and (c) the required data analysis skills - together with the route you are considering. If the main journal article you are interested in fails any of these tests, it is probably worth considering another article.

STEP THREE

Work out which of the three routes is possible based on your chosen main journal article

You now need to think more carefully about each of the three routes you could follow. Typically, you should be able to find a number of justifications to follow any one of these three routes for a given journal article. After all, most research, if not all research, needs to be duplicated, generalized and extended in some way. Therefore, you can either keep an open mind about the three possible routes you could follow, and assess the journal article(s) you are interested in from all of these routes, or select a particular route and focus in on finding suitable justifications for that route. Before you work your way through these justifications, just remember that choosing a route is a balance between your personal interests and academic justifications discussed in the guide above, and any deal breakers that may stop you being able to pursue a particular route. In order to assess which of these three routes is possible based on the journal article(s) you are considering, we recommend going back to the introduction to these three routes: Route #1: Getting Started. Make sure that you know the main characteristics of a Route A: Duplication, Route B: Generalisation and Route C: Extension dissertation. When thinking about these three routes, think about the journal article(s) you are interested, and consider the following questions:

• Route A: Duplication

  Do you think that the same results would have arisen if you carried out exactly the same study again?

• Route B: Generalisation

  Do you think that the same results would have arisen if a different population, treatment, setting/context, or period of time was applied?

• Route C: Extension

  Are there aspects of the original study that need to be challenged or built on by adding constructs and variables, looking at new measures and methods, making changes to the research design, or through using new analysis techniques?

If the answer to the question for Route A: Duplication or Route B: Generalisation is NO, these routes are available to you. Even if the answer is YES in the case of Route B: Generalisation, there is an argument for examining the generalizability (i.e., external validity) of the results from the journal article you are interested in. If the answer is YES to the question for Route C: Extension, this route would also be available to you.

At this point, you should select the particular route you prefer, remembering to balance your personal interests and academic justifications, and any deal breakers that may stop you being able to pursue a particular route. Once you feel confident in your choice of main journal article and route, move on to STAGE THREE: Setting research questions and/or hypotheses.