The information needed to provide support/evidence for or to understand client "needs", "gaps" in the world and project "scope" are all different types of information that may be found in different places. Below are some suggested staring places to start your searches on "gaps" in the world.  

If you are struggling to find information, please see the "Getting help!" tab on the left.

Identifying the "gap" in the world that your "need" is addressing goes beyond what your client tells you (or in many cases beyond what your client even knows exists!). Information that can help you identify the "gap" can be found using a state-of-the-art, cutting-edge or prior art searches. Search in technical journal articles, review articles, conference proceedings, professional journal articles (e.g. trade publications) and patents to see if a "need" has already been filled by something else that exists.

Using the databases below you can limit in your results to articles, conference proceedings or magazines (for trade publications). Compendex and IEEEXplore are engineering specific databases. Proquest, Scopus and Web of Science are multidisciplinary. 

You can also do similar searches in the library catalouge to find articles and books.

Patents are also a resource to understand what inventions exist to fill a "gap" through a prior art search. Use the patent guide below to learn about what a patent is, how read and find patents. You can also do simple searches for patents in Google patents.