‘Means with meaning’ when used for transmission of messages is called ‘information’, their evolution over the past is described. Information encoded in medium is called ‘informatic product’ directed at changes of mental states. In linguistic modelling information is carried in the subordinate clauses of certain dynamic verbs. This notion is used for developing ‘selective’ and ‘semantic’ information in which ‘quantity of information’ is related to ‘variation’ and ‘precision of information’. A ‘design methodology’ for design of information systems is demonstrated. Dynamic linguistic modelling is used for developing ‘prototypes’ of information systems which show how information is propagated in time towards outcome or final state of change of mental state and how it is used for compensating resistance to change.