The PSSUQ (Post-Study System Usability Questionnaire is a 16-item standardized questionnaire. It is widely used to measure users’ perceived satisfaction of a website, software, system or product at the end of a study. PSSUQ originated from an internal IBM project called SUMS (System Usability Metrics) in 1988. A few rounds of improvements have resulted in PSSUQ Version 3, which is the one used today.
You may find different versions of PSSUQ available online and the way to differentiate them is to look at the number of questions. There are 18 questions in Version 1; 19 questions in Version 2; and 16 questions in Version 3.
Another alternative to PSSUQ is the System Usability Scale (SUS).
PSSUQ (Post-Study System Usability Questionnaire)
PSSUQ Version 3 consists of 16 questions with 7 options (+ NA option) to choose from. The sample below shows a PSSUQ questionnaire to measure the usability of a website.
On a scale between Strongly Agree to Strongly Disagree, please rate the following statements regarding Amazon:
- Overall, I am satisfied with how easy it is to use this system.
- It was simple to use this system.
- I was able to complete the tasks and scenarios quickly using this system.
- I felt comfortable using this system.
- It was easy to learn to use this system.
- I believe I could become productive quickly using this system.
- The system gave error messages that clearly told me how to fix problems.
- Whenever I made a mistake using the system, I could recover easily and quickly.
- The information (such as online help, on-screen messages, and other documentation) provided with this system was clear.
- It was easy to find the information I needed.
- The information was effective in helping me complete the tasks and scenarios.
- The organization of information on the system screens was clear.
- The interface of this system was pleasant.
- I liked using the interface of this system.
- This system has all the functions and capabilities I expect it to have.
- Overall, I am satisfied with this system.
Measuring PSSUQ (Post-Study System Usability Questionnaire)
PSSUQ follows a 7-point Likert Scale (+ NA option). The overall result is calculated by averaging the scores from the 7 points of the scale. Unlike SUS, as there are more questions in PSSUQ, it also has 3 sub-scales, namely system usefulness, information quality, and interface quality.
- Overall: the average scores of questions 1 to 16
- System Usefulness (SYSUSE): the average scores of questions 1 to 6
- Information Quality (INFOQUAL): the average scores of questions 7 to 12
- Interface Quality (INTERQUAL): the average scores of questions 13 to 15
Interpreting PSSUQ (Post-Study System Usability Questionnaire)
PSSUQ score starts with 1 (strongly agree) and ends with 7 (strongly disagree). The lower the score, the better the performance and satisfaction.
However, 4 is neutral but may not be the average and a score below 4 does not indicate that your website, software, system or product have performed above average.
One of the advantages of using standardized usability questionnaires such as PSSUQ is its replicability. You can easily replicate PSSUQ across your studies. When you do so, you will be able to derive the PSSUQ average for your particular system.
As PSSUQ can be further broken down into Overall score, SYSUSE score, INFOQUAL score and INTERQUAL score, you should also examine closely the scores for each of the 16 questions. For instance, most of the systems tend to perform worse for question 7 which is “The system gave error messages that clearly told me how to fix problems.”. This implies that more efforts should be put in to design a good error message. An investment in UX Writing may be necessary to ensure a simple yet consistent voice.
Several academic research performed to test on the reliability of this scale as well as determining the norm of constructs and individual questions. To make sense of the scores derived from PSSUQ version 3, the following means determined by Sauro and Lewis (2016) involving 21 studies and 210 participants may be helpful in interpreting the scores you get from your research:
- SYSUSE: 2.80
- INFOQUAL: 3.02
- INTERQUAL: 2.49
- Overall: 2.82
More details can be found in their book Quantifying the User Experience: Practical Statistics for User Research (2nd Ed):
Online PSSUQ Calculator
Need to calculate PSSUQ score on the go? Use our online PSSUQ calculator to calculate now.