Date of Award

Summer 6-2022

Degree Type


Degree Name

Doctor of Philosophy (PhD)



Committee Chair

Steven Venette

Committee Chair School


Committee Member 2

Kathryn Anthony

Committee Member 2 School


Committee Member 3

John Meyer

Committee Member 3 School


Committee Member 4

Paul Alberti-Strati

Committee Member 4 School


Committee Member 5

Laura Alberti

Committee Member 5 School



This dissertation used Power of Speech Style (POS) theory’s powerless linguistic cues (hedges, hesitations, intensifiers, and tag questions), Information Manipulation Theory and McCroskey’s Speaker Credibility Scale to determine if perceived honesty mediates the relations between a speaker’s use of powerless linguistic cues and evaluations of that speaker’s credibility. Two studies were conducted. The first study tested these variables' relationships with an experimental design involving reading a courtroom witness transcript. An EFA was conducted to determine appropriate factors for perceived information manipulation. Then mediation analysis using PROCESS included four parallel mediators from the previously tested EFA. The second study provided replication and extension of study one by including three new message transcript scenarios between physician-patient, politician-constituent, and professor-student. Additional covariables such as gender, lie acceptance, political affiliation, perceived threat severity of pain medication, and student responsibility were included to account for any undue influence on the dependent variables. The results produced a new measurement with a CFA for the Information Manipulation Scale (IMS), a reordering of items for the factor structure of speaker credibility, and advice for improving speaker credibility by prioritizing the removal of hesitations from one’s speech. Additionally, intensifiers were identified as not being powerless linguistic cues and should not be included in future studies of POS. Future research was proposed for how to overcome limitations of these studies, and various ways in which the new IMS and speaker credibility measurements can be tested and further validated.