The scope of a topic is like a boundary line around a territory that specifies what is inside and what is outside the area. It defines the problem space you are addressing. State not only what the research is about but also what it is NOT about, by discussing what important others have done that is outside your topic, e. g. if the topic is online grocery shopping distinguish this from other forms of online shopping and from e-commerce in general. When the scope is poorly defined authors wander freely in areas of little relevance to their topic and consequently annoy informed readers.
If the scope too broad the research may not adequately cover it, while a too narrow scope will limit the implications. It can be hard to define a “Goldilocks” scope that is “Not too hot, not too cold, but just right”. For example, for a project on the hydro-chemistry of surface water, be clear on the sorts of water it applies to and the sort of chemistry involved. Don’t be surprised if the scope changes as you progress. The scope description is what others use to assess if the research is relevant say to a journal or conference call for papers, so it is very important.
Define the scope early, as defining it later creates ambiguity about goals. The scope affects the limitations of the research, the data used, the theories that apply and the conclusions made, e.g. it can explain why a certain data or subjects are excluded from the research. It also helps to manage expectations.
Key terms. Key terms are the main constructs that the research addresses. Defining the key terms correctly and using them consistently is critical to properly defining the scope of the research. Give any abbreviations used in full the first time they are used, e.g. ISP (Internet Service Provider). Where possible, use accepted definitions rather than giving terms your own meaning to avoid confusion. If necessary, take the time to define terms that you interpret differently, e.g. my paper on software politeness defined it as giving choices rather than being nice. Always define key terms carefully.
Scope is important because it prevents critics from misinterpreting your research. Stating what research is not about immunizes it against battles you don’t want to be involved in. In this case, scope acts like a disclaimer on a product, such as “Not to be used by infants”, e.g. research on the correlates of cancer may disclaim that it implies any causal links. Define the research scope early to clarify the purpose and avoid misinterpretation.