A ticker symbol is the code used to facilitate securities trading on an exchange like the New York Stock exchange or NASDAQ. Finding a ticker symbol is useful in company research for two reasons.
1. It confirms the company is publicly traded.
2. Because ticker symbols are carefully controlled you know that any source that includes that ticker symbol is definitely talking about that company. For instance, there are dozens of companies named Kraft, and even more than one Kraft Foods (in other countries). If you search for the ticker KRFT using advanced search in our databases, you know that every result is about the Kraft Foods that makes the mac and cheese and American cheese slices.
Publically traded companies have all kinds of disclosure requirements dictated by the Securities and Exchange Commission. That is good for your research because it means most of the information you need is easily available through library databases or out on the web.
Private companies are just that, private. They don't have to disclose very much information and so most don't. Even the ones you think are warm and fuzzy. You may be able to cobble together enough information through newspaper and magazine articles but it will involve a lot more work on your part and you still may not get all the information you need.
Checking for a ticker symbol from the link above or looking a company up in Lexis-Nexis are the best ways to determine if a particular company is publically traded. You can make some informed guesses though.
1. Publically traded companies are usually giant and produce many products or provide many services that are household names acroos the country.
2. Private companies are usually smaller, focus on a regional or local market, and probably specialize in just one or two areas.
The #1 cause of not being able to find a report on a company is that it is not publicly traded. If you can, the best thing to do is switch to a publically traded company.
Searching through vendor or company-created white papers can help you understand more about the issues facing a particular company.