The situation analysis and SWOT require a lot of secondary research in addition to whatever primary research you might be conducting. Particularly, they help you to understand the environment a company, organization, or client finds themselves in. This often involves learning more about the company or organization, industry, market, and competitors to understand an organization, product, or service's competitive advantage and weaknesses, as well as opportunities and threats that might exist.
Looking at your marketplace
To aid in your situation analysis and SWOT analysis, you will want to look at your clients competitors - or where else your client's customers or audience could go to have their need met. While library databases can give you a good start on identifying competitors, that's typically not where the customer starts their search or learns about a new product or service.
Think about how the customer, user, or audience might find your client. Where could they find competitors as well? For a local business, this might be a Google maps or Yelp search. For a non-profit, it might be a Google or Facebook search. For an app, its likely to be an app store. Medical device? Where might doctors and other medical and healthcare professionals find new products and technology?
*"the marketplace' in this sense is a great place to get a sense of what audience/customer perceptions of competitors might be, via reviews and feedback. Taken with a grain of salt, this can be a useful resource.
Understanding your target audience is another piece of the puzzle. While primary research will likely be the most useful (because you control what questions you are asking and who is responding), secondary research is a good first step.
Marketing or communicating to businesses, organizations, or working individuals is different than communicating directly to consumers. If you're cause or client needs to be seen by businesses or organizations, think about who might need to see your message? Who are the gate keepers and decision makers?
Include the search term 'decision makers', 'purchase decisions', gate keepers, 'business to business', etc. when searching for information about how to reach these key people in organizations. IBISWorld can also be useful here, to break down important business issues for business and organizations.
It's easy to tap into the 'pulse' of a cause by turning your attention to relevant Facebook, Instagram, and Twitter pages (as well as others). Who are the important voices talking about an issue or cause? How are followers or visitors to the page engaging with the content?
Public Opinion + Surveys
Whatever your cause, there's likely print/web publication, non-profit organization, institution, or marketing company that cares about it in some way. Many of these entities will have conducted research of their audience or the general population to try and understand opinions about their issues. Using a search engine like Google is often the quickest way to find reports that contain those research or survey results.
Try the following search techniques:
'keywords about your cause/issue/topic' + survey, data, report - sometimes including industry, consumer, customer, audience can be helpful as well.
Bonus tip! Many times formal research reports are made available as a .pdf file. Search for them specifically in Google using filetype:pdf at the end of your search.
While we might not think of it as made for communication professionals (and while it's quite dense), academic research from all disciplines can better help us understand our audiences, causes, and problems within businesses, organizations, or society that need solving, and more.