Free Interactive PSSUQ Calculator & Guide for Usability Researchers
Introduction
Measuring system usability is crucial for any successful UX research project, and the Post-Study System Usability Questionnaire (PSSUQ) is a reliable, industry-standard tool for doing just that. Developed by IBM in the late 1980s, the PSSUQ provides quantitative insights into users' perceptions of a system’s usability, covering essential aspects like system usefulness, information quality, and interface quality.
If you’re a senior UX researcher, product manager, design lead, or a business stakeholder new to usability research, understanding and using the PSSUQ effectively can make a significant impact on your product’s user experience. In this guide, we’ll cover how to set up your study, interpret each question in the PSSUQ, and use our free, interactive PSSUQ Calculator to simplify your data analysis.
Download the free PSSUQ Questionnaire (PDF) to streamline your usability testing and gather valuable user feedback efficiently!
What is the PSSUQ, and Why Is It Important?
The PSSUQ is a standardized usability assessment tool that asks users to rate different aspects of their experience with a system immediately after a usability test. The questionnaire measures:
System Usefulness: How well the system meets the user’s needs.
Information Quality: The clarity and helpfulness of the system’s information.
Interface Quality: The ease of navigation and interaction with the system.
By analyzing user responses, you can pinpoint specific areas for improvement and quantify the overall usability of your product.
Setting Up Your Study
Before diving into data collection, ensure your study is set up to yield meaningful results.
When to Use the PSSUQ: Use the PSSUQ immediately after a usability test session, when users’ experiences are still fresh. It’s suitable for evaluating software, websites, or any interactive digital product.
How to Administer It: The PSSUQ consists of 16 questions, and users rate each item on a scale from 1 (Strongly Agree) to 7 (Strongly Disagree). Lower scores indicate higher perceived usability.
Sample Size Considerations: While there’s no strict rule, aim for at least 5-10 participants for preliminary studies and more for robust data. The larger the sample, the more reliable your insights will be.
Understanding the PSSUQ Questions
Each question in the PSSUQ maps to a specific aspect of usability. Here’s a quick breakdown:
System Usefulness (Questions 1-6): These items measure how effective and efficient the system is for users.
Example: “Overall, I am satisfied with how easy it is to use this system.”
Information Quality (Questions 7-12): These questions assess whether the information provided is clear, accurate, and helpful.
Example: “The information (such as online help, on-screen messages, and other documentation) provided with this system is clear.”
Interface Quality (Questions 13-16): These items evaluate the quality of the interface design and the ease of navigation.
Example: “The interface of this system is pleasant.”
Note: Consistently low scores in a category can signal critical areas for improvement.
How to Use the Interactive PSSUQ Calculator
Our free, interactive PSSUQ Calculator simplifies the data analysis process, saving you time and effort. Here’s how to use it:
Input Your Data: Enter the scores for each question as rated by your study participants.
Automated Calculations: The calculator will automatically compute averages for each subscale (System Usefulness, Information Quality, Interface Quality) and the overall usability score.
Interpreting Results:
Overall Score: Lower scores indicate better usability. Compare your results against benchmarks or past studies to see where your product stands.
Subscale Averages: Identify specific areas that need attention, such as unclear information or a difficult-to-use interface.
Best Practices for Using the PSSUQ
To ensure your data is accurate and actionable, follow these tips:
Context Matters: Always consider the context in which users interacted with the system. Was it a realistic setting? Did they have prior experience with similar systems?
Use Follow-Up Interviews: The PSSUQ provides quantitative data, but qualitative follow-up questions can add depth to your understanding. Ask users to elaborate on high or low scores to uncover specific pain points.
Benchmark Your Results: If possible, compare your PSSUQ scores to industry standards or your past usability tests to track improvement over time.
Try the Free Interactive PSSUQ Calculator
Try my free, interactive PSSUQ Calculator designed for usability researchers and UX professionals. Quickly measure system usability and gather insights to enhance user experience. Perfect for evaluating software, websites, or digital products.
Your support keeps these resources free for everyone. Consider donating if you find them valuable. ☕
PSSUQ Calculator
Welcome! 🙂
Simply copy and paste your data from Excel or Google Sheets.
Results
System Usefulness Average: -
Information Quality Average: -
Interface Quality Average: -
Overall PSSUQ Score: -
| Participant Number |
System Usefulness (SYSUSE) | Information Quality (INFOQUAL) | Interface Quality (INTERQUAL) | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | |
How It Works: This tool runs entirely in your browser using HTML, CSS and JavaScript. Your data stays private and is never saved or sent anywhere.
It’s also open-source — you can view the code on GitHub for full transparency.