sentences:  It has been extended to explain why people join activist groups; internal and external dimensions have been identified for problem recognition, level of involvement, and constraint recognition; and research has been conducted to determine whether information campaigns (which generally are passively processed) can create publics.Among them, some research on the situational theory has examined external and internal dimensions of the three independent variables (Grunig & Hon, 1988; Grunig, 1997).If the three concepts (problem recognition, constraint recognition and involvement), are internal (only perceived), then they could be changed by communication, and if they are external (real/actual), then “changes must be made in a person’s environment before his or her perceptions … and communication behavior will change” (Grunig, 1997, p. 25).