We see it as a major challenge for any account of human communication to give a precise description and explanation of its vaguer effects. When the communicator's intention is to marginally increase the manifestness of a wide range of assumptions, then each of them is weakly communicated. There is, of course, a continuum of cases in between. In the case of strong communication, the communicator can have fairly precise expectations about some of the thoughts that the audience will actually entertain. With weaker forms of communication, the communicator cam merely expect to stir the thoughts of the audience in a certain direction.
Communication alters the mutual cognitive environment of the audience and communicator.