94% of the participants did not complete all the assigned trials. That left 30 participants Who did, and among those, 9 cats were found to select " at least one stimulus by sitting within the contours (illusory or otherwise) with all limbs for at least three seconds."
So when they're saying this should be repeated in a controlled setting, they're not kidding. Why does a citizens scientist decide to not complete a study involving their cat? How about boredom, because their cat doesn't do anything?
It is completely possible that there was a strong bias.
With that said, all research has its limits. I think the authors have been very honest to discuss their findings and the limitation of the context - best case scenario someone takes the idea to the next level, worst case scenario we know it's a limited study and not conclusive.
So when they're saying this should be repeated in a controlled setting, they're not kidding. Why does a citizens scientist decide to not complete a study involving their cat? How about boredom, because their cat doesn't do anything?