Measuring-Perceived-Usability.md

Measuring Perceived Usability

Genesys includes support for adding three types of self-reported quantitative data to your prototypes:

• Single Ease Question (SEQ)
• System Usability Scale (SUS)
• Task Load Index (TLX)

Adding a Single Ease Question (SEQ)

The Single Ease Question is a post-task questionnaire administered at the end of every task in a test session. It has been validated and demonstrated as reliable, valid, and sensitive.

• They allow you to compare which parts of your interface (or workflow) are perceived as most problematic, since the data is collected after every task.
• Since the task was just completed, it's fresh in the participant's mind, allowing a clear indication toward the experience, without subsequent tasks obscuring memory.

To add a Single Ease Question to your prototype page:

1. Ensure that you have loaded the Genesys Style Sheet on your prototype page. You can do this by typing gns-stylesheet in the HEAD section of your page.
2. Place your cursor where you want the SEQ added and type gns-feedback-seq.
3. Type in an identifier for your page at the highlighted cursor.

Adding a System Usability Scale (SUS)

The SUS is a post-test questionnaire, given to a participant after an entire usability testing session has completed. The SUS has a long history of validity and reliability.

To add a System Usability Scale to your prototype:

1. Add a new prototype page that will only contain the SUS.
2. Ensure that you have loaded the Genesys Style Sheet on your prototype page. You can do this by typing gns-stylesheet in the HEAD section of your page.
3. Place your cursor where you want the SEQ added and type gns-feedback-sus.

Adding a Task Load Index (TLX)

The NASA-TLX is another type of post-task questionnaire, applicable to complex or mission-critical products or tasks used by trained individuals. Since this is a complex questionnaire that should be answered after every key task, it will add time to the overall test process. Use this to evaluate systems where human errors are highly undesirable.

To add a Task Load Index to your prototype:

1. Add a new prototype page that will only contain the SUS.
2. Ensure that you have loaded the Genesys Style Sheet on your prototype page. You can do this by typing gns-stylesheet in the HEAD section of your page.
3. Place your cursor where you want the SEQ added and type gns-feedback-tlx.

Capturing Measured Usability Data

To capture your user's perceived SEQ and SUS results for collation and analysis, refer to the section on Recording User Test Sessions.

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References

• Beyond the NPS: Measuring Perceived Usability with the SUS, NASA-TLX, and the Single Ease Question After Tasks and Usability Tests