Credibility is fragile. It is either promoted or discouraged on every page of a website. Visitors will judge the companies credibility based on the credibility of their website. Incorporating the seven following guidelines will improve the credibility of a website, causing visitors to remain longer on the website, which leads to an improvement in its key performance indicators.

'Persuasive technologies apply principles of social psychology in influencing people; principles of credibility, trust, reciprocity, authority and the like'

(Ijsselsteijn, 2006, p. v).

Why ‘Credibility’?

The research literature identifies credibility as a key factor encouraging visitors to remain longer on a website. Staying longer on a website results in wider exploration of the site, leading to more opportunities of interaction with the visitor. (Colbert, Oliver & Oikonomou 2014)

Credibility affects the key performance indicators of a website because of the ‘halo effect’. Cardello and Nielsen (2013) defines the Halo Effect as ‘when one trait of a person or thing is used to make an overall judgment of that person or thing. It supports rapid decisions, even if biased ones’ (n.p). An example of the halo effect on a website is when ‘the quality of a website's internal-search results are used to judge the overall quality of the site, and, by inference, the quality of the brand behind the site and its products’ (Cardello & Nielsen 2013, n.p). What this means, is visitors will make judgments about a company, based on the credibility their website. Therefore, keeping the halo effect in mind is important when planning a website and defining its key performance indicators.

Highly Credible Websites

Below are seven design implications to consider when planning a highly credible Web experience. Each of these guidelines were recommended by the Persuasive Technology Lab at Stanford University (Fogg et al., 2001), in a paper titled; ‘What makes Web sites credible?: a report on a large quantitative study’. The study ranked each credibility element on a scale of importance (See Tables 1-6, 8), which is helpful when planning or re-designing a website. The results of this study are further supported and expanded upon by examples from more recent studies.

A credible website must prove to the visitor that the real world organization associated with the website actually exists. The results from the Persuasive Technology Lab study support this notion (Table 1). The elements tested in the study were cutting edge back in 2001, such as placing a physical address and employee photographs on a website. Today, Google® local maps are commonly used to reinforce real world location but were not common in 2001, so they were not considered in the study. This is not to say that the results listed below are not valid today, it is pointing out that the list of elements below are not exhaustive, there may be others elements not considered here. Nevertheless, when planning a site for maximum credibility, designers need to consider how to highlight each of the following elements, to communicate the accessibility and legitimacy of the real world organization.

Table 1: Real-World Feel Scale (Cronbach's alpha = 0.66)

Item Website Element Mean Value
1.1 Provides a quick response to your customer service questions. 2.02
1.2 Lists the organization's physical address. 1.86
1.3 Provides a contact phone number. 1.71
1.4 Provides a contact email address. 1.53
1.5 Shows photos of the organization's members. 0.69
(Adapted from: Fogg et al., 2001)

The gray literature provides a study done by Nifty Marketing, which identified the characteristics of an optimal local landing page, ranking high in the search engines. Their study chose 100 random websites from major and minor US cities (80:20 ratio) to observe what each local landing webpage had in common. The study did not have access to the analytics of each site. The study confirmed that ‘name, address and phone number’ were essential factors. In addition, the study found 34% of websites included a Google® map, showing the companies geographic location. They found that photos also depicted buildings (stores, warehouses and corporate headquarters) and services. The results, while not a vigorous scientific enquiry, provide further elements for highlighting the ‘real world’ facets of the organization. (Nifty Marketing 2012)

To further expand on the elements already mentioned, a commercial report by Nielsen, Molich, Snyder & Farrell (2000) concluded users also wanted to see:

Making a website easy to use is commonly known as usability. Jakob Nielsen, one of the industries foremost experts in Web usability, explains ‘Usability is a quality attribute that assesses how easy user interfaces are to use. The word ‘usability’ also refers to methods for improving ease-of-use during the design process’ (2012, n.p). The return on investment in website usability is high. Nielsen argues that spending ~10% of the design project budget on usability, will more than double the websites required metrics (2012, n.p). However, there is also another compelling reason for investing time and money in usable design: it improves credibility.

While usability is often discussed, of equal importance is its utility. Both usability and utility combine to determine whether a website is useful. What this means is, a usable website will not be credible if it is not useful.

Making a website useful is a key component of its credibility. To support this notion the study by the Persuasive Technology Lab, asked test subjects to award points to elements of a website ‘that made sense’ and deduct points if elements of a site were difficult to use. The results from the findings are listed below (Table 2.). The results indicate that a usable website is perceived to be more credible. It may also be reasonable to conclude that a simple website with usability would be perceived more credible that a lavish website lacking usability (Fogg et al., 2001).

Table 2: Ease of Use Scale (Cronbach's alpha = 0.67)

Item Website Element Mean Value
2.1 Allows search for past content (i.e. archives). 1.57
2.2 Appears professionally designed. 1.55
2.3 Arranged in a way that makes sense. 1.48
2.4 Takes a long time to download. -0.94
2.5 Difficult to navigate. -1.30
(Adapted from: Fogg et al., 2001)

There is much written on website usability. For further advice on how to make a website more usable, see the Nielsen Norman Group articles:

Expertise is a key component in credibility (Fogg et al., 2001). However, among psychologists there is no commonly accepted definition of expertise (Frensch & Sternberg 1989). For the purpose of website credibility, the online business dictionary defines expertise as the ‘Basis of credibility of a person who is perceived to be knowledgeable in an area or topic due to his or her study, training, or experience in the subject matter’ (WebFinance Inc. 2014). In the real world, an expert person is not necessarily a smart person (one wouldn’t ask Einstein to fix a toothache), an expert person is knowledgeable within a certain ‘area or topic’. This is also true for websites displaying expertise. The website designer must convince users that the author of the website is an expert on a certain area or topic.

The results from the Persuasive Technology lab (Fogg et al., 2001) supports the notion that credibility is enhanced by the conveyance of expertise on a website. The ‘expertise’ elements tested in the study back in 2001 (Table 3.) did not include such elements as videos, which are commonly used in 2014 to convey expertise. The frequently asked questions (FAQ) page may also be utilized to demonstrate expertise. For this reason, it is conceivable other ‘expertise’ elements also exist. According to the Persuasive Technology lab, the conveyance of expertise through the use of ‘expertise’ web design elements may be one of the most underutilized ways of leveraging credibility.

Table 3: Expertise Scale (Cronbach's alpha = 0.63)

Item Website Element Mean Value
3.1 By a news organization that is well respected outside of the Internet. 1.91
3.2 Lists authors' credentials for each article. 1.49
3.3 Articles that list citations and references. 1.49
3.4 Has few news stories but gives detailed information for each. 1.10
3.5 Says it is the official site for a specific topic. 0.85
3.6 Ratings or reviews of its content. 0.79
3.7 Displays an award it has won. 0.45
3.8 Contains information that doesn't match what you think. -0.77
3.9 Many news stories without giving detailed information. -0.89
(Adapted from: Fogg et al., 2001)

Trustworthiness, another dimension of credibility, is defined by ‘the terms well-intentioned, truthful, unbiased, and so on. The trustworthiness dimension of credibility captures the perceived goodness or morality of the source’ (Fogg et al., 2001, p. 62). By designing an honest, unbiased and candid website, web designers enhance credibility, which leads to a more effective website. Fogg et al., (2001) contrasts this outcome to a promotional approach. Trustworthiness is a key component in developing credibility. A simple violation of trust can destroy years of slowly accumulated credibility.

The more a user trusts a website, the larger the risk they are willing to take when dealing with the website. As with expertise, the results from the Persuasive Technology lab (Fogg et al., 2001) concluded that trustworthy elements displayed on a website also lead to increased perceptions of credibility. In the Persuasive Technology lab study, ‘trustworthiness’ elements tested included: links, policies and domain names (Table 4.). Many possible markers for trustworthiness exist.

Table 4: Trustworthiness Scale (Cronbach's alpha = 0.57)

Item Website Element Mean Value
4.1 Represents an organization you respect. 1.93
4.2 Linked to by a site you think is believable. 1.29
4.3 States its policy on content. 1.26
4.4 Links to outside materials and sources. 1.25
4.5 Contains links to its competitors sites. 1.11
4.6 Was recommended to by a friend. 1.07
4.7 Represents a nonprofit organization. 0.93
4.8 Lists well-known corporate customers. 0.62
4.9 The URL for the site ends with ‘.org’ 0.58
(Adapted from: Fogg et al., 2001)

The report by Nielsen, Molich, Snyder & Farrell (2000), interviewed 64 participants, for an average of 2-hours each, in their investigation of 20 e-commerce websites. Their report (p. 2) provided the following additional elements for displaying trustworthiness on a website:

Other suggestions to enhance trustworthiness by Bloomtools™ (2009) include the use of testimonials, an ‘about us’ page, warranties and guarantees.

While credibility perceptions are increased by tailoring the user experience for each individual, it is not as vital as the other suggestions. An example of this may be when returning to a website, it displays the visitors name and suggests articles and products based on previous sessions. There are many possible variations to tailoring the user experience in this way. The Persuasive Technology lab (Fogg et al., 2001) reports that ‘even to the type of ads shown on the page: ads that match what the user is seeking seem to increase the perception of Web site credibility’ (p. 67). Further results from their study are included in Table 5.

Table 5: Tailoring Scale (Cronbach's alpha = 0.44)

Item Website Element Mean Value
5.1 Sends emails confirming transactions. 1.41
5.2 Selects news stories according to your preferences. 0.57
5.3 Recognizes that you have been there before. 0.37
5.4 Requires you to register or log in. 0.07
(Adapted from: Fogg et al., 2001)

If possible, avoid placing advertising on a website. The study by the Persuasive Technology lab (Fogg et al., 2001) suggests that websites that aggressively promote commercialism are penalize by their users (Table 6.). Credibility is lost when a clear distinction between advertisements and content is not made. From their study Fogg et al., (2001) report that ‘mixing ads and content received the most negative response of all’ (p. 67). However, it is important to note that when banner ads are well designed, they can enhance the perceived credibility of a website. In contrast, using pop-up advertisements annoy users and therefore reduce credibility. A balanced approach is required if a website is to promote commercial activity. Users accept commercialization but become skeptical when it is overdone.

A post on the Google® Webmaster Central Blog (undated on Feb. 2014), provides further reasons for designers not to include too many advertisements on a website. The algorithmic change to Google® pushes websites ‘top-heavy’ with advertisements down the search engine rankings. Google® says its reason for doing so, is that when websites contain too many ads, it ‘makes it hard to find the actual original content on the page’ (Google® 2012, n.p). This change by Google® reflects their desire to deliver credible search results.

Table 6: Commercial Implications (Cronbach's alpha = 0.65)

Item Website Element Mean Value
6.1 Advertised on the radio or on billboards. 0.57
6.2 Provides financial news at no charge. 0.53
6.3 Have ads that match the topic you are reading about. 0.21
6.4 Designed for e-commerce transactions. 0.17
6.5 Has a commercial purpose (as opposed to academic purpose). -0.63
6.6 Requires a paid subscription to gain access. -0.71
6.7 Has one or more ads on each page. -0.77
6.8 Automatically pops up new windows with ads. -1.56
6.9 Difficult to distinguish ads from content. -2.08
(Adapted from: Fogg et al., 2001)

Nielsen (2004) asserts that websites that use advertising know little about how it affects their visitors or the degree to which it undermines their credibility. The use of techniques, such as popups do not only reduce the credibility of the website, the dislike extends to the advertisers. Nielsen (2004) reports on a survey of 18,808 users, which showed pop-up advertising affected 50% of participant opinions of the advertiser very negatively and nearly 40% of participants reported their opinion of the website was effected very negatively. Research in 2004, based on 605 respondents; investigated how users perceive online advertising. The results of this study identify each of the design element that reduced the credibility of the website (Table 7). Websites with advertising should consider that 80 to 90% of advertising techniques are strongly disliked by users. Using them will only result in reducing credibility.

Table 7: Commercial Design Elements Reducing The Credibility Of A Website.

Item Website Element Users Answering ‘Very Negatively’ or ‘Negatively’
7.1 Pops-up in front of your window. 95%
7.2 Tries to trick you into clicking on it. 94%
7.3 Does not have a "Close" button. 93%
7.4 Covers what you are trying to see. 93%
7.5 Doesn't say what it is for. 92%
7.6 Occupies most of the page. 90%
7.7 Blinks on and off. 87%
7.8 Floats across the screen. 79%
7.9 Automatically plays sound. 97%
(Adapted from: Nielsen 2004)

Users quickly evaluate a site by its visual design alone. The research in this area shows that in as little as 50 milliseconds, a visitor to a website has decided whether remain on a website or not, a decision based mainly on the page’s visual appeal (Lindgaard, Fernandes, Dudek & Brown, 2006). These first impressions go on to determine the visitors judgments on such things as the sites usability, its credibility and purchasing intentions (Web Site Optimization, 2006). Due to the dramatic effects the sites visual appearance has on the visitor, the visual design of a website should not be left to non-professionals.

A pleasing visual design is almost impossible to quantify due to its highly subjective nature. Alsudani & Casey (2009) define this as unity, which they explain ‘is responsible for the attractive visual appeal of the web site as a whole’ (p. 514). Designers apply the relationships of balance, harmony, contrast and dominance, to websites to achieve ‘Unity’. This is not a task for amateur website designers. Even seemingly ‘small’ issues, such as one typographical error, a single broken link, a blurred image or some perceived inconsistency is damaging (Table 8.). Designers almost need to be obsessive to avoid any imperfections that could impact on a websites credibility. (Fogg et al., 2001)

Table 6: Commercial Implications (Cronbach's alpha = 0.65)

Item Website Element Mean Value
8.1 Updated since your last visit. 1.55
8.2 Offers information in more than one language. 0.04
8.3 The site is small (e.g. less than 5 pages). -0.28
8.4 Hosted by a third party (e.g. AOL, Geocities). -0.44
8.5 Domain name does not match the company's name. -1.06
8.6 Has a typographical error. -1.28
8.7 The site is sometimes unexpectedly unavailable. -1.28
8.8 Has a link that doesn't work. -1.45
8.9 Links to a site you think is not credible. -1.53
8.10 Rarely updated with new content. -1.67
(Adapted from: Fogg et al., 2001)
What To Expect

Does integrating these credible factors into a website make any difference to a websites key performance indicators? A recent study by Colbert, Oliver & Oikonomou (2014) investigated whether credibility had any effect on the click through rate of advertised content. The study tested three websites with high, medium and low degrees of credibility. Each version of the site contained the same content (articles and sponsored content) and the same architecture (structure, navigational scheme etc.). However, the ‘elements’ around each article, and the superficial appearance of the article, was modified to suggest different levels of credibility, in line with the same seven guidelines established by the Persuasive Technology Lab listed above.

From a total sample of 578 unique visitors and fifteen remote usability tests, ‘the high credibility site achieved the highest CTR per visitor (8.45%), the site with medium credibility actually achieved the lowest CTR per visitor (3.68%), and the low credibility site achieved CTR of 5.31%’ (Colbert, Oliver & Oikonomou 2014, p. 63). These results provide proof that site design and content creation increase persuasiveness without impairing user experience. The credibility of the website encouraged longer visits, this in turn, created more opportunities to click through on sponsored content. For websites to fully benefit from greater credibility, the study concluded that designers are ‘advised to encourage engagement at the same time as they attempt to increase credibility’ (Colbert, Oliver & Oikonomou 2014, p. 65).

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