One of the things that bothers me in fiction is sloppy or non-existent research. The internet has made research easier, but you have to check sources carefully. We’re human and we’re going to make mistakes, but my advice is to learn to research in a library the old-fashioned way first so you at least have some idea of what you’re looking at online. Example: Toni Morrison’s been taken to task for including starlings in A Mercy. Is the occasional anachronism or inaccuracy a problem? Depends on whether it takes the reader out of the narrative. Practice good research and it will lessen the odds that your reader will say, ‘wait a minute…’
Sometimes my research branches off into something that isn’t pertinent, but oddly timely. Turns out that today, Hilary Clinton is scheduled to preside over a ceremony honoring those in our foreign service who’ve died on duty. I was looking for pictures of eyes of Somalis and Ethiopians in order to describe a character and found the very sad story of Brian Adkins who was murdered in Ethiopia. I initially found an article that he was found dead, then looked further to find out what had happened. May he rest in peace.