They should take into account, first of all, the subject matter, or content, which each medium communicates in its own way. They should also take into account the circumstances in which the content is communicated - the purpose, that is to say, the people, the place, the time, etc.
Kwanza kabisa wanatakiwa kuyazingatia yale yote yanayoletwa na kila chombo kulingana na tabia yake, wote wanatakiwa kuwa macho juu ya mazingira – yaani lengo, watu, mahali, wakati, n.k. – ya mawasiliano.