Maybe it would help if I gave an example of a test protocol that's been used to test a similar claim.
Let's take a claim of astrology: that horoscopes are accurate descriptions of people. That, if you like, there is structured intelligence in the data generated by the movements of planets against the background of stars.
So we get a bunch of astrologers to draw up detailed horoscopes of people they've never met, given only their date, time and place of birth. Now we can't just give the subjects their horoscopes and ask them if they're accurate, because of The Forer Effect. Forer was a psychologist who, way back in the 1940s I think it was, gave a bunch of students a personality test to fill in, and then gave each of them what he told them was their personalised personality profile, based on their answers, and asked them to rate it for accuracy of a scale of 1 (nothing like me) to 5 (very accurate). He got an average score of 4.3. Only then did he tell them that he had, in fact, given them all exactly the same profile (which, as it happens, he had compiled by stringing bits of newspaper horoscopes together).
This is a reproducible result. Over 90% of people, given any supposedly personalised reading whatsoever and believing it to have personalised for them, will score it 4 or 5 out of 5 for accuracy. This is what we mean by subjective interpretation.
So how, then, can we eliminate the Forer Effect when testing the hypothesis that horoscopes are accurate? The easiest way to do it is with a simple blind test. Instead of giving each subject what they know is their own horoscope to assess for accuracy we give them, say, three - their own, and two others selected at random - and ask them to pick out the one they think is theirs. The one that seems to be the most accurate, that resonates with them the most. Now, if all that's going on is the Forer Effect then all three will appear to be roughly equally accurate, and the one that's actually theirs will only be the one they pick out as often as you would expect by chance, i.e. one time in three. But if there's anything to astrology at all then they ought to be able to pick out theirs - not necessarily every time, but significantly more often than would be expected by chance. So you set the success criteria to the hit rate that is statistically significantly more than the chance rate.
That's the sort of test protocol you need to test your hypothesis.