Post-Study System Usability Questionnaire
What is it?
PSSUQ is an alternative to the System Usability Scale (SUS). It's widely used to measure users' perceived satisfaction with a website, software, system, or product at the end of a study.
How it Works?
Is a 16-item standardized questionnaire with 7 options. 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.
What Measures?
Overall Reactions to the Software, like:

  • System Usefulness (SYSUSE)
  • Information Quality (INFOQUAL)
  • Interface Quality (INTERQUAL)

What are the Pros and Cons?
Has been used successfully to:
  • Retain and expand product usage
  • Communicate and capture executive value

PSSUQ score starts with 1 (strongly agree) and ends with 7 (strongly disagree). The lower the score, the better the performance and satisfaction. This is uncommon, as most other questionnaires use high numbers to indicate a better score (e.g., the SUS and SUPR-Q). But, PSSUQ correlates highly with the SUS and other UX metrics.

  • Its replicability. You can easily replicate PSSUQ across time or versions. And has some benchmarks available.
  • Replicability and robustness in psychometric terms.
  • Is composed of only positive-tone items.
  • Can be further broken down into Overall score, SYSUSE score, INFOQUAL score, and INTERQUAL score;
  • It's highly sensitive. Is able to detect differences across a large number of variables such as the type of system used, user group, years of use, range of experience with different systems, stage of system development, and type of evaluation.
  • It's effective at small sample sizes. Small, free, and highly reliable.

  • Post-study metric
  • PSSQ has its scale reverse. Meaning, better response options are on the left side which appears to increase the number of response errors.
  • If we were able to change one thing about these questionnaires, it would be to reverse the endpoints of the items.
What PSSUQ Covers?
As PSSUQ can be further broken down into Overall score, SYSUSE score, INFOQUAL score, and INTERQUAL score. 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 effort should be put into designing a good error message.

System Usefulness (SYSUSE)

  1. Overall, I am satisfied with how easy it is to use this system.
  2. It was simple to use this system.
  3. I was able to complete the tasks and scenarios quickly using this system.
  4. I felt comfortable using this system.
  5. It was easy to learn to use this system.
  6. I believe I could become productive quickly using this system

Information Quality (INFOQUAL)

  1. The system gave error messages that clearly told me how to fix problems.
  2. Whenever I made a mistake using the system, I could recover easily and quickly.
  3. The information (such as online help, on-screen messages, and other documentation) provided with this system was clear.
  4. It was easy to find the information I needed.
  5. The information was effective in helping me complete the tasks and scenarios.
  6. The organization of information on the system screens was clear.

Interface Quality (INTERQUAL)

  1. The interface of this system was pleasant.
  2. I liked using the interface of this system.
  3. This system has all the functions and capabilities I expect it to have.
  4. Overall, I am satisfied with this system.
Improving Usability Evaluation by Automating a Standardized Usability Questionnaire. Available from: [accessed Jan 27 2021].
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