Literature reviews are one of the most critical elements of any lengthy piece of social research as it forms the backbone of the wider theoretical base of any topic. In terms of the process of writing any longer study, the literature review is essential for grounding the topic and seeing, through the work of others, what issues related to the potential topic are most worth exploring and where the largest areas of contention, agreement, or discord lie among scholars and other researchers. While it is quite possible to form a hypothesis or central research question without first pouring through the literature, it generally seems that through “researching the research" a possible hypothesis can be refined, of not completely revolutionized, by examining what already exists.
For instance, without doing at least a preliminary literature review first, one might find that the central research question chosen has already been written about extensively and with a great deal of concurrence among the scholars, thus making it an unsuitable topic as the argument is far too easy and obvious. Since a solid research question rests on the writer’s ability to make a valid and contestable argument, only the literature review process would reveal that a topic is either “done to death" or has life left for a new reworking or new way of conceptualizing it.
In addition to revealing these possibilities (or lack of them) a literature review forces the writer to engage with other scholars who have worked with the same topic and to consider the nature of their research (for example, it’s limitations) and use this to further solidify the final product. This in turn leads to the revelation of new avenues in terms of broader theories to look at more closely and points to related sources that might not have been immediately discovered.
In terms of my own topic related to the effects of supervisors on employee morale in the workplace, I found that my initial research question, while interesting to me, was far too broad. An initial scan of the literature available revealed that this was indeed a topic that had been written about extensively and with the same conclusion—that yes, there is an observable impact on how employees relate to their supervisors (on many levels), thus reading several pieces on this topic led me to realize my topic needed refined far further.
The next step I took was to look at the many pieces I had gathered as many possible sources and to look for common themes in some of them. As this process continued, I was able to use a thematic approach to narrow down my topic and this guided me through long process of deciding what among this existing literature was still worth arguing and what would make the most valuable contribution from my questions. This process also prompted me to research theoretical principles I came across that were unfamiliar and required a process of sub-research areas. These secondary concerns then helped me form some rudimentary secondary/supporting questions. In short, writing a literature review is important because it forces evolution of the first working hypothesis—sometimes into something barely related to the initial idea.