You could be measuring a ride experience at Disneyland, the driving experience of a Tesla, a medical device in the operating room – or your website’s experience… You may think that you want to measure satisfaction or delight, learnability, effort or event time on task. These are all important factors, but the most important thing to measure is task completion.
All experiences are an activity or series of activities and those activities are made up of tasks. The task is the fundamental building block of an experience. If you cannot complete a task then your experience fails. If you are developing software, making medical devices or sending a rocket to the space station, if the task fail, you don’t release the software, ship the device or launch the rocket. The same is true for the experiences that you deliver.
How do you measure task completion? You conduct a usability evaluation. Usability refers to the quality of the experience. Usability evaluation focuses on how well your audience can use your products and services – the experience you deliver – to achieve their goals.
To measure task completion, first you must understand your customer’s goals then design a test around the completions of those goals. Measure each task. It could be as simple as they could or could not complete the task – pass/fail – or you could measure the nuisances like ‘the task was completed with some assistance’ or ‘the task was completed successfully but the participant took a slight detour or made one or two small mistakes’ or ‘the tasks was completed but with significant delay and frustration.’
You may want to use a rating system to easily quantify and communicate the task completion. If you are just measuring pass/fail then 1 and 0 are best. They are easy to calculate for reporting findings to inform recommendations. If you are measuring the nuances then you need a more elaborate rating system like a scale of 1 to 4. There are several standard rating systems to choose from.
The important thing is that you measure task completion when creating your experiences. Measure iteratively throughout the design and development process with people that best match your target audience.