I am often asked to examine seemingly mysterious and inherently ambiguous photos. Usually the person asking has already settled—sometimes tentatively, more often strongly—on a specific interpretation. They know what the photo shows and want my independent confirmation that their favored interpretation is correct. That shadowy blur in the distant forest is a Bigfoot; that weird white orb—complete with faint facial features if you just magnify enough—is a ghost, and so on.
One of the first steps to analyzing a photograph, and more broadly a claim, is carefully distinguishing between what is known, what is suspected, and what is assumed. The three are often casually lumped together, but parsing them out is important. Usually key premises are possibilities instead of established fact. Considering alternative explanations is another part of the process.
If you’ve taken any standardized multiple-choice tests such as the GRE, LSAT, or ACT, you probably remember that some of the questions offered a tricky option, usually after three or four possibly correct specific answers. This is some version of “The answer cannot be determined from the information given.” This response, often Option D, is designed in part to thwart guessing and to see when test-takers recognize that the question is insoluble or the premise incomplete.