Facilitated communication is a method of communicating with someone who is non-communitative = e.g. in a coma, severe autism or locked-in syndrome. This usually relies on electronic or printed boards with basic phrases and letters on, or it may be simply holding a pen in their hand and moving it for them or even holding their hand above a keyboard. These are used with another person who interprates the letters or words on behalf of the patient. This method of communication is completely subject to misintereptation and to the ideomotor effect. Despite their claims to the contrary, the person who interepts for the non-verbal patient is clearly responsible for the message being produced.
When these methods have been applied previously, completely uneducated people make huge leaps, this is likely to be the person relay the message rather than they non-verbal person has suddenly developed new skills. For instance, they can "speak" in foreign languages or have a writing age considerably in advance of what they had before. Amazingly it often correlates with the abilities of the facilitator.