COMM 339 -- Persuasion

Dr. Lee McGaan  

  Office:  WH 308  (ph. 309-457-2155);  email
  Home:  418 North Sunny Lane (ph. 309-734-5431, cell 309-333-5447)

Fall 2016 Office Hours:   MWF:  9:30 - 10am, 11am - Noon & 1 -2pm TTh:  2-3pm & by apt.  |  copyright (c) by Lee McGaan, 2006-2016

Source Credibility Research 
last updated 2/17/2016

 Definitional Concepts


i.   Credibility is in the eye of the beholder - faked credibility is as good as the real thing (AP p. 124)

ii.  Credibility is situational and contextual

iii.  Credibility is an interactive process among sources, messages, and receivers

iv.   Credibility influences both believing and yielding

v.   The effect of credibility on attitude change is smaller in the central route (AP 14)


 Cronkite and Liska described four categories of factors influencing source credibility

   Cronkhite, G. and Liska, J.  (1976) A critique of factor analytic approaches to the study of credibility.  

Communication Monographs, 43, 91-107

i.   Source characteristics - looks, vocalics, gestures, verbal style, organization of message.

ii.  Attributes inferred about the source - intelligence, occupation, knowledge, race goes either way (see AP 12,  p.124-5)

iii.  Functions the source performs - relating to the topic (e.g. addict as source on drug use)

iv.  Criteria employed by receivers to judge source suitability to speak are situational


 Other General Source Characteristics affecting credibility (from a variety of other researchers)


i.   attitude similarity and common ground - occasionally dissimilarity is helpful

ii.   social adjustment

iii.  status and recognition

iv.  dynamism and humor

v.   evidence and information

vi.   physical characteristics - (be appropriate in dress, etc)

vii.   communication skills (appropriate to situation - vocal pleasantness, linguistic diversity, audience and feedback analysis skills)


 How to deal with irredeemable low ethos  (AP 14)


i.    act in ways contrary to your apparent self-interest -- violate listener expectations for the source

ii.    create the impression that you are not trying to influence others (e.g. let them "overhear" private conversations, hidden camera, etc.)


 Manufacturing Credibility  (AP 14 & 15)


i.   make sure public knows of your successes, many small or trivial ones are fine - set low expectations.

ii.   media models are more effective at influence than preaching 

(1)  bandwagon effect works!

(2)  media models can teach that a behavior is appropriate and legitimate.