I suppose you could look at both of those from a scientific approach, but I think you'd miss out on a lot of emotion and feeling which can make all the difference to a reading, some appreciate a clinical 'tell it like it is approach' while others prefer a softer delicately phrased approach.
This can make it difficult for any 'reader' because in the few moments before you begin you have to appraise your client you have to assess mental stabuility, their attitude, how open or closed they are, how much you can give them, put in place boundaries ie 'how much can they take' the psychic bit starts well before the read lol