What makes a Usability Metric different from other metrics?
Unlike other metrics, usability metrics are forward looking. The metrics help you find the problems even before users get to buy the product.
Usability Metrics are the only measurement of a person’s experience with a design.
Compared to other metrics, they are the only measurement that allow you to elicit a person’s real attitudes and behaviours while interacting with a design.
They enable businesses to validate the “gut feeling”, hunches and opinions etc by providing real measurable data even before the launch of a product.
Types of Usability Metrics
Self Reported Metrics
It is the best way to evaluate the effectiveness and efficiency of designs.
They are the best way of knowing how well users are actually using a product.
Performance metrics tell the what very well but not the why.
Performance Metric Types
Task success: Measures how effectively users are able to complete a given set of tasks.
Time-on-task: Measures how much time is required to complete a task or to measure if the target users can complete the tasks within the expected time.
Errors: Measures the errors made during task completion. Two types of errors are usually measured: slips and mistakes.
Efficiency: Measures the amount of effort a user expends to complete a task, such as the number of clicks in a website or the number of button presses.
Learnability: It is the extent to which something can be learned. Long term or short term.
Issued-Based Metrics (Issue types)
Measure anything that prevents task completion.
Measure anything takes users off course.
Measure anything that creates some level of confusion.
Measure anything that produces an error.
Measure how many users did not see something that should have been noticed.
Measure how many people assumed they were correct in their task completion when they were actually wrong.
Measure how many people assumed they have completed the task when they have not.
Measure how many people did incorrect actions/steps across and individual tasks.
Measure how many people have misinterpreted the various interface elements.
Issued-Based Metrics (Metric types)
Number of issues per iteration or frequency of unique Issues.
Frequency of Issues per Participant.
Frequency of Participants per issue type.
Issues by Category.
Issues by Task.
Self Reported Metrics
Ease of Use: Using a 5 point or 7 point Likert scale to rate the ease of use.
Usefulness: Using a 5 point or 7 point Likert scale to rate the usefulness.
Ease of Learning: Using a 5 point or 7 point Likert scale to rate the ease of learning.
Satisfaction: Using a 5 point or 7 point Likert scale to rate the ease of satisfaction.
After-Scenario Questionnaire: Three questions to validate the effectiveness, efficiency and satisfaction. Rating is done using a 5 –7 point scale.
Quantitative Metrics types are often called objective because they are based on data that is quantifiable and measurable.
Qualitative Metrics types are often called subjective because they are not based on data but on perception of the individual or group. The users perception is often influenced by emotions, opinions, personal feelings or attitudes etc.
In conclusion, these are what the different types Usability Metrics are and how they varies from the others. We hope this article benefits you. Stay tune to our next blog post where we will be sharing with you on more tips regarding the various topics. Also, you can check out our previous blog post where we have discussed topics on Mobile First Approach UX Guide and SEO or SEM?.