CRV micromovements are a special set of movements which are performed by the viewer without the viewer's knowledge, but which reveal information about the viewer's reactions to the target, about things at the target site, and about how the session is progressing. CRV micromovements are different from a viewerr's natural micromovements, in that they are specially trained into the viewer by the monitor - usually over months or years of time.
To begin the process, the monitor must first learn all the viewer's natural micromovements. In that way, no CRV micromovement will mistakenly match a natural one. After this is done, the monitor then begins training in meaningful micromovements, one-by-one, until a full physical language is built up between the viewer's subconscious mind and the monitor. This is done without the viewer's knowledge, and the viewer must never be allowed to know what his/her CRV micromovements are.
The first CRV micromovement is usually one which allows the viewer's subconscious mind to signal to the monitor that the viewer is allowing his/her conscious mind to take over, and is therefore getting "off target". The next is usually one which allows the monitor to see that the viewer has just gotten on target again. When the monitor sees these physical micromovements, he/she makes a note of them, and passes that to the analyst. The analyst can then look at the monitor's notes and see, for example, that the viewer gets off target on page 5, but gets back on target on page 8. This allows the analyst to know how much credibility to give to the the information on each page.
The full process of developing CRV micromovements is very complex and lengthy, and cannot be taken up in the span of this definition. Supervised training is definitely required.
See also, "micromovements" and "natural micromovements".