A mason starts a castle wall by finding a very excellent and sturdy stone, and, once having put it into place, he looks for another stone to fit onto it. If the second stone doesn't fit, he tosses it to the side and looks for one which does. The attempt is to make a single smooth, seamless surface which is strong and will resist attack. CRVers are prone to do the same with perceptions. Rather than accepting every perception and reporting it, we tend to want things to fit. We want them to make sense.
When we get the slightest idea of what the target is into our heads, we tend to start being selective about the new perceptions - do they fit our mental picture or not? Do they make sense in light of our previous perceptions or not?
When a viewer begins "castle building", he/she will even begin to filter out those impressions which do not fit. The tendency is to say, "Well, if X were true, then this impression must meanů", or to say, "If X is true, then this can't be right!" The result is a form of "AOL drive" which is long, organized, and very well constructed The castle you are building starts being in charge of your session.
The perceptions you report are now being censored by your conscious mind, not simply a report of what is perceived by your subconscious. As a result, the results are almost always wrong.
But there is an even larger problem. There will be a growing certainty in your mind that you have " really nailed" the target. This begins a spiral effect where growing certainty makes you more prone to filter out any contradictory information and actively seek any perception which would reinforce the castle walls. The perceptions gained then increase the certainty in your mind, continuing the spiral. The session starts to really feel good, and you feel like you are really on target, This is one of the major reasons why you cannot judge the accuracy of a target by how the session feels. When a person judges a session done on a target which has no feedback (an esoteric target), they almost always judge the accuracy of their session by how much contact they felt they had with the target. The fact is that the greater the feeling was, the more likely the results are to be wrong. The fact is that when a session starts really feeling good, you are probably off-target and building a castle. This leads to the rule in CRV, "If it feels good - don't do it."
See also, "Peacocking", "esoteric target", "AOL" and "STRAY CAT".