Market research is an necessary step in cultivating an idea from germ stage to when it can bear fruit. Is it a good idea? Does it already exist? Is it cost effective? Is there competition? These are the questions that may be answered by conducting research into the existing markets. Just as there may be multiple solutions to a single design problem, so too, there may be multiple ways to gather useful information. Below are links to free and subscription-based resources that may provide useful information.