Sensodyne is a famous company which sells toothpastes. Its toothpastes are especially designed for customers who have sensitive teeth. In this advert, the dentist clearly pointed out the importance of sensitive teeth caring. After increasing the awareness of sensitive teeth caring on customers, the dentist demonstrated his professional knowledge by explaining the functions of the toothpaste, Sensodyne Complete Protection. Then, he recommended them to use it. Obviously, this advert used the persuasive technique, expert-unknowing public altercast. This technique is based on the idea that when people do not know much about an issue, they are more likely to be persuaded by the sources with professionals’ opinion.
Tobin and Raymundo (2009) had done a research on the effect on source expertise. They investigated how the level of source expertise and the strength of the argument would affect persuasion of a message. In the experiment, participants were required to read an essay. The essay was about the heath and well being of university students. The participants were told that a well known social scientist who specialized in psychological well being wrote the essay. In the high expertise condition, the last paragraph of the essay mentioned that the scientist’s was recognised in the research field whereas in low expertise condition, the last paragraph included the information that the findings of the scientist were doubt by other scientists.
After that, the participants watched a persuasive message about extending the spring break in university. For strong arguments, the author argued that some extremely undesirable consequences would happen to the students while for weak arguments; the author only introduced some general undesirable consequences.
Result showed that in high expertise condition, participants were more persuaded by weak arguments. Yet, strong arguments were more persuasive when they were in low expertise condition. This study demonstrates that an expert’s persuasiveness is stronger when people do not have enough information of that issue.
Tobin, S. J., & Raymundo, M.M. (2009). Persuasion by causal arguments: The motivation role of perceived causal expertise. Social Cognition, 27, 105-127.