I spend a huge chunk of my time swimming in a sea of data that people have carelessly amassed on the assumption that data is inherently valuable. And frequently I come to the conclusion that this data has negative value. The people who collected it failed to record enough information about the data's provenance. So I don't know what kind of processes produced it, how and why it was collected, any transformations that might have happened on the way to storing it, etc. Without that information, I simply cannot know for sure what any of it really means with enough precision to be able to draw valid conclusions from it.
The best I can do is advise caution, say that this data can help us form hypotheses whose only true use is helping us form a plan to collect new data that will help us answer the question we have. What I'm typically asked to do instead is make a best guess and call it good.
The former option is just the scientific method. The latter option is the very essence of pseudoscience.
That second word in my job title gives me some anxiety. I'm keenly aware that most people are more fond of the word "science" than they are of the intellectual practice we call science. The people who like to amass data are no exception.