SUS: How to Easily Grade Your Site’s Usability
Post from November 27, 2009 (↻ June 5, 2021), filed under Art and Design.
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The System Usability Scale (SUS) is a Likert scale-based questionnaire to grade the usability of systems, which John Brooke created back in the 80s. SUS results yield a score between 0 and 100, with 100 indicating “best” usability.
Now, since websites can be considered “systems,” SUS can also be used to grade websites (“WUS”). And here’s a way how you can easily set up, use, and benefit from that. Grab the Website Usability Scale spreadsheet, make a copy of it through your own Google account, and use the new form to ask your own users a few questions.
That’s the short version. Here’s a more comprehensive how-to:
- Log in to your Google account, for the questionnaire templates are based on Google Docs.
- Open your preferred SUS template—either take the original System Usability Scale template, or the customized Website Usability Scale template, which talks about “websites,” not “systems.”
- In the top left, select “File”.
- Then, choose “Make a copy…”.
- Keep or change the name of the copy.
- Remove the first line in the spreadsheet which only contains dummy data:
- Right-click on the row number, “2”, which should select the whole row and also display a context menu.
- Select “Delete row”.
- In the file menu at the top, go to “Form (0)”.
- Choose “Go to live form”.
- Voilà—you should now see the form you can ask to fill out: send them the URL, link the survey form from your site, whatever you prefer.
- You’ll see the results appear in your SUS spreadsheet copy; on “Sheet2”, the spreadsheet automatically calculates the SUS score. As noted before, the closer the number gets to 100, the better.
Feel free to ping me in case there are any issues .
Please note that neither SUS nor WUS is a substitute for user testing. It is more of a low cost method to evaluate usability, and to put some number on it. That it doesn’t get used more frequently, considering its age, beats me, but is exactly the motivation for me to point to it, and to make it easier to implement.
Whether SUS can be used as a standard evaluation tool for websites, however, stands and falls with its adoption—your tests—as well as more testing and feedback from usability professionals. I have some experience when it comes to usability research, testing, and evaluation, but my core domain is still something else. With this as the closing remark, try SUS and please share your thoughts and findings.
If you’ve got a minute, please also take a quick survey rating meiert.com.
Update (March 4, 2010)
Luis Guilherme created a Portuguese spreadsheet template for SUS. Very cool!
I’m Jens Oliver Meiert, and I’m an engineering manager and author. I’ve worked as a technical lead for Google, I’m close to the W3C and the WHATWG, and I write and review books for O’Reilly. Other than that, I love trying things, sometimes including philosophy, art, and adventure. Here on meiert.com I share some of my views and experiences.
If you have questions or suggestions about what I write, please leave a comment (if available) or a message.
On December 1, 2009, 15:54 CET, website laten maken said:
This sounds quite interesting. I never heard of this before, but I will definitely try and read more about this!
Filled in the rating for your site 😊
On December 1, 2009, 23:20 CET, Dave said:
Very cool template. I’m not currently able to survey my users in this way, but the SUS/WUS questions are good food for thought about whether my site is meeting their needs.
On December 6, 2009, 18:39 CET, Mike Johnson said:
This is awesome. Thanks for posting. Looking forward to using this.
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Perhaps my most comprehensive book: The Web Development Glossary (2020). With explanations and definitions for literally thousands of terms from Web Development and related fields, building on Wikipedia as well as the MDN Web Docs. Available at Apple Books, Kobo, Google Play Books, and Leanpub.