In this TV advert, created by Dyson, viewers are shown the new Dyson Ball, and why it is a much better vacuum cleaner than your standard 4 wheel appliance. Viewers are introduced to James Dyson, the Inventor, who talks us through why this new Dyson is revolutionary and will change the way you clean your house forever.We are encouraged to believe that James knows what he is talking about when it comes to hoovers, and therefore the Dyson Ball would be a very good purchase.
Hovland and Weiss (1951) investigated how source credibility can affect people’s attitudes. In their study, participants were shown articles on little known topics, such atomic submarines and the steel shortage and told that the articles were either written by a high credibility source or a low credibility source. Participants rated their opinion on the topic both before and after reading the article.
|Figure 1: Percentage of attitude change depending on source credibility and time since reading article|
As figure 1 shows, there was a significant difference between low credibility and high credibility sources immediately after reading the article. This is demonstrated through the high credibility group’s increase in attitude change on the topic by around 24%. On the other hand, the low credibility group’s attitude change was only around 6%. From this initial finding, we could conclude that having a highly credible source leads to more attitude change than a low credibility source because we trust the opinion of the ‘expert’ and thus adjust our attitudes accordingly. However, over time, it is clear that the high credibility source becomes discounted, since 4 weeks later, the difference in attitude change decreased whereas the attitude change for the low credibility source had increased. This demonstrates that over time people forget where the source of information came from, affecting their attitudes towards the given concept.
Overall this result indicates that whilst a high credibility source (such as the Dyson Inventor, James) are effective immediately after their opinion is provided, over time, it does not matter if the source is of high or low credibility, because most people will end up feeling the same for both. In the case of the Dyson vacuum cleaner, unless the viewer is planning to buy a hoover in the near future, I doubt they would remember how good the Dyson Ball is when they finally come to buy a new one. I certainly couldn’t remember anything about the hoover until I saw the advert recently, so I doubt I would have picked it when purchasing a new one.
Hovland, C. I., & Weiss, W. (1951). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635-650.