Boost Your Web Credibility: Learn From The Pro’s
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Boost Your Web Credibility: Learn From The Pro’s

on / by Sabina Idler

As promised, we’re back with the results from our web credibility test case that we previously introduced. We are very pleased with the results as they seem to be in line with previous findings on web credibility by experts in the field. The findings of this test case support the assumption that different aspects on a website can either increase or decrease it’s perceived web credibility.

Figure 1 – heatmap showing elements that were perceived to increase the website’s credibility
Figure 1 – heatmap showing elements that were perceived to increase the website’s credibility

Short intro

The goal of this test case was to measure different drivers for credibility. To do so we tested six websites and asked participants to mark elements that made them trust or distrust the website. For more details about our test method, please check the first posting on this test case, Help us to unravel credibility on web pages.

In this post we will briefly introduce the term credibility, explain why credibility is so important, and introduce the credibility guidelines created by persuasive design expert, BJ Fogg. After this we will dive into our test results and link them to the guidelines suggested by Fogg. Last but not least, we will draw a conclusion on our findings and give a short perspective on website credibility.

Credibility – What is it anyway and why is it important?

Before we begin, it might be useful for some readers to take a step back and have a look at what exactly credibility is in the first place and why its necessary to pay special attention to it. In his presentation about website credibility, Fogg defines website credibility as a combination of trustworthiness and expertise. So, according to Fogg, if a website is perceived as truthful and unbiased, then the people behind the site should also be perceived to be experienced and knowledgeable, and therefore the user sees the website as credible.

Why is this credibility important? Well, actually it is more than just important, it can be a crucial factor for the success of a website for two main reasons. The first reason being that a credible website appeals to people. Considering the huge amount of information offered on the World Wide Web, it has become more important than ever to stand out. The second reason is the ability to change people’s attitude and behavior towards a website.

Credibility guidelines by BJ Fogg

BJ Fogg has become an expert in the field of persuasive design, based on his three years of research and studies with over 5,500 participants which include lab experiments, surveys, online experiments, and content analysis. Fogg has since came up with ten guidelines for designing credible websites. Below you will find a short synopsis of the ten guidelines, for a more detailed explanation of the guidelines, please have a look at Fogg’s original presentation.

  1. Design your website so it looks professional (or as appropriate for your site’s purpose).
  2. Make it easy to verify the accuracy of the information on your site.
  3. Show that there’s a real organization behind your site.
  4. Highlight the expertise in your organization and in the content and services you provide.
  5. Show that honest and trustworthy people stand behind your site.
  6. Make it easy to contact you.
  7. Make your site easy to use – and useful.
  8. Update your site’s content often (at least show it’s been reviewed recently).
  9. Use restraint with any promotional content (e.g., ads, offers).
  10. Avoid errors of all kinds, no matter how small they seem.

Results of our credibility test case

With these guidelines in mind we would like to have a look at the results of our case study and perhaps we will be able to link them to some of the aspects covered in Fogg’s guidelines.


Most participants found the overall design of a website to be an important criteria for credibility, according to our test results. In particular, elements such as pictures, dominant colors and the company’s logo played an important role. For example one website showed a dominant red background, which was perceived as ‘evil’, ‘dangerous’, and ‘hurting their eyes’ by some test participants. Another website was mainly designed in very dark colors which was considered to be ‘too dark’ and ‘obscure’. There were no positive reactions to these extreme colors. Another website was mainly designed in a light grey which lead to both positive and negative feedback in regarding to the website’s credibility.

Another important design element of a website is the company’s logo. For most of the websites in this test case, the logo provoked both positive and negative reactions amongst the participants. Most comments made indicated a personal like or dislike for the design.

Also pictures displayed on the website resulted in approximately the same amount of positive and negative feedback. For example the picture below (Picture 2) was commented to show a ‘real life person’ to whom participants could relate and also as ‘bad looking face’ that participants could not at all relate to. The high number of participants marking design aspects of the websites indicate that Fogg certainly has a point with his first guideline when he says that the design is important and that a website should look professional, but the opposing results also reveal that design perception is a very individual and thus a difficult matter.

Picture 2 – left: perceived to increase credibility | right: perceived increased credibility
Picture 2 – left: perceived to increase credibility | right: perceived to decrease credibility

Testimonials, quotes and references

Testimonials, third party quotes, and references were shown to have a positive influence on web credibility. Those elements actually seemed to be very important since they were consistently marked by the majority of participants and comments similar to the one seen in the screenshot below show participants’ appreciation for such content. Only a few participants marked the same elements as not trustworthy, arguing that they cannot identify with a person shown for e.g. in a photograph or that they don’t know the company that is being cited. This again shows that the perception of whether or not an element is considered to increase credibility highly depends on the individual. Being able to verify the accuracy of information, corresponds to Fogg’s second guideline.

Figure 3 – testimonies perceived as increasing credibility
Figure 3 – testimonies perceived as increasing credibility

Who is behind it?

Feedback on all six websites indicated that it was important for the participants to know which company and whose responsible for the presented content. This information was identified as an important trust indicator. A website was perceived as trustable if there were contact information and especially if there was a physical address available. In addition a public privacy statement was considered an important aspect indicating if the user was taken seriously or not. FAQs were described to indicate interest in the user and were rated as a positive influence on the perception of credibility. Participants also expressed their wish for this kind of information if it was not presented. These findings can be referred directly to the third, fifth, and sixth guidelines which point out the importance of knowing who is behind the website and how they can be contacted.

Professionalism and expertise

There were several indications showing that perceived expertise on a website is another important aspect for credibility. The test results also give an insight on what elements were considered to be related to expertise. Participants commented on several different aspects such as the design: ‘The general design has a certain quality and structure to it which suggest a professional organization’, a live preview of the product: ‘To see a live video makes me think their product is working’, or the the logo: ‘Well known company, professional logo’. Fogg describes this in his fourth guideline that a company’s self confidence is an important indication for trustworthiness for users.


The degree of usability on a website is also very important for the overall perception of credibility as indicated by several remarks from participants. Some of the participants commented that they appreciated a detailed sitemap, because it demonstrates to them what the site has to offer. A lot of participants also stated that the live preview of a product on one website as very helpful tool to understand the content. Another website offered to try their product before signing up for it, which was also very appreciated by the test case participates. On the other hand, websites that did not give any or very little clues about their content, were generally rated as negative in regards to their credibility. Also small letter types that were difficult to read were mentioned by several participants as decreasing in credibility. Last but not least, participants also recognized if a layout was not consistent or lacked coherence, and considered it to be a negative influence on the site’s credibility. Usability as a credibility factor can be seen as a direct correlation to the seventh guideline by Fogg, which suggests to create a useful and usable website.

Figure 4 – Sitemap was perceived as increasing credibility
Figure 4 – Sitemap was perceived as increasing credibility


Errors even if made on purpose, can decrease the trustworthiness and perceived credibility of a site, as seen in the screenshot below. A participant noted that a grammatical error was made on purpose in order to match a popular linguistic style, yet still it was perceived as ‘too cool’. Fogg also claims in his last guideline to avoid errors of any kind because they decrease the credibility of a website.

Figure 5 – Grammar mistake perceived as decreasing credibility.
Figure 5 – Grammar mistake's are perceived as decreasing factors in credibility.


Another aspect that was identified by participants as a decreasing factor for credibility was inappropriate wording. This was only the case on one website but most participants recognized it, stating that it was too direct and suggestive in it’s wording, as can be seen in Figure 6. Besides, the website used slogans that seem to offend participants judged by comments like ‘I don’t think that they know what I want in life’. Using the correct wording to address the user was not mentioned in Fogg’s guidelines, but judging from the reactions we received from participants, one should consider  it an important aspect of website credibility.

Figure 6 – Inappropriate wording perceived as decreasing credibility.
Figure 6 – Inappropriate wording can be perceived as deterrent in credibility.


After a short introduction to the ten credibility guidelines by BJ Fogg, we looked at the test results from our last test case. We found that several aspects were perceived to influence website credibility, some of which were design related and others content related. We could link most of our findings to the guidelines presented by Fogg and we were even able to added our own addition guideline – the importance of wording. There were two guidelines which were not directly addressed in our findings, which were the frequency a site is updated and promotional content. According to our test results, the aspect of site updates did not seem to influence participants’ perception of credibility.


Credibility is a crucial aspect for a good website. Credibility appeals to users and it can influence their attitude and behavior. With only two simple questions, participants are able to give feedback and identify elements that either contributed to credibility or deterred it. Let’s keep in mind, though, that there are some aspects of creditability that are easier to identify than others.

Do you want to find out if users trust your website? Set up your own credibility test in minutes and find out!

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Article by

Sabina Idler

Sabina was technical writer & UXer @Usabilla for 5 years before she started her own UX research and consultancy firm; UXkids. With UXkids, Sabina leverages her academic research expertise, know how in child development, and strategic vision to help companies build successful digital products for children. You can connect with Sabina on Linkedin or follow her on Twitter.

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  • i want to try the credibility test..hehe thanks
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