In 2006, the Centers for Disease Control and Prevention (CDC) elected to revise and update their website (CDC.gov). One of their primary goals during this redesign process was to optimize the usability of the homepage, as well as some of the second-level pages. As part of this usability testing process, Cari Wolfson and I conducted a series of usability tests – one of these was the first FirstClick usability test. A more detailed account of this testing program can be found in a later blog posting, and is also found as Case Study 10.3 in Tom Tullis’ and Bill Albert’s book, Measuring the User Experience (2008).
We studied the factors contributing most to each person’s success on a task. By looking at click streams and success rates, we found an interesting relationship between the user’s success in making their first click and their eventual success with the entire task.
After this first experience, we continued to investigate the ‘firstclick’ concept from 2007 through 2009 in a series of tests conducted at several different agencies in the U.S. Government. We continued to observe that the first click was a very critical click. When participants had difficulty with their original decision, they frequently had problems finding the overall correct answer for the entire task scenario.
We focused on the first click participant’s made after reading the scenario. Because each scenario took participants less than 30 seconds, this type of testing enabled us to considerably increase the number of scenarios we used. For example, in one test each participant completed 136 scenarios during a one-hour testing period.
Eventually, we had data collected on 12 usability studies. For each study, we reported data on (a) the overall success rate, (b) the percentage correct of ‘firstclicks’, (c) the percentage incorrect of ‘firstclicks’, and (d) the ratio of correct to incorrect clicks. All studies were conducted on different websites, and used different participants. This table shows the results.
We found that if the first click was correct, the probability of getting the entire scenario correct was .87 (range from .72 to 1.00). On the other hand, if the first click was incorrect, the chance of eventually getting the scenario correct was only .46 (range from .29 to .70). This means that there was less than a 50-50 chance of being successful. Overall, participants were about twice as likely to succeed on a task if they selected the correct response on their first click.
Based on our findings, we suggest that you work hard to ensure that the first click is a correct click. Many times, the first click is made on the homepage, but not always. Because of the success of many search engines, at least 50% of users may access a site from pages that are not the homepage.
Bailey, R.W. (2007), User Interface Update – 2007: Annual review of the usability literature for practitioners, Computer Psychology Training Course.
Bailey, R.W., Wolfson, C.A. and Nall, J. (2008), Revising a Homepage: Applying Usability Methods that Guarantee Success, Proceedings of the UPA.
Tullis, T.S. and Albert, B. (2008), Measuring the User Experience, Boston: Morgan Kaufmann Publishers, 256-257.
Wolfson, C.A., Bailey, R.W., Nall, J. and Koyani, S. (2008), Contextual card sorting (or ‘firstclick’ testing): A new methodology for validating information architectures, Proceedings of the UPA.