Usability Goal Setting

Every product that follows a human-centered design must include usability goals. Generally, there are two types of goals; qualitative and quantitative goals.

Qualitative usability goals

Qualitative goals are some general unquantified goals that act as a guide for product design. These goals are broadly stated and can not be measured. This might make it difficult to determine whether the goals have been met in the final design. An example of a qualitative goal for a highly interruptive environment should be that “the system should provide enough context information for users to remind them what they were doing and where they were in case they get distracted.” Some more examples of qualitative goals for various design system may include:

• The system should allow group operations.
• The system should provide consistency across pages and components.
• The system should be self-explanatory and easy to remember to support complex tasks for infrequent users.

Quantitative usability goals

Quantitative usability goals are quantified, measurable, and objective goals. It is easy to determine whether these goals are met or not, which makes them fit to be used as acceptance criteria during the design evaluation process. An example of a quantitative goal could be that a search page should not take longer than 50 seconds to load a search result. Quantitative goals can be expressed as either ease-of-use goals or ease-of-learning goals depending on the user expertise level.

• Ease-of-use goals: Ease of use is determined by the system’s speed, flexibility, and efficiency for an experienced user. For example, experienced users should take no more than 10 seconds on average to find a file in a folder.
• Ease-of-learning goals: Ease of learning is determined by the effort and time required by novice or infrequent users. For example, a novice user should take no more than two minutes on average to sign up for a social media account.

Based on the type of quantification, the quantitative goals can generally be classified as either absolute or relative goals.

• Absolute goals: These are the goals with absolute quantification. For example, users should not take more than 30 seconds on average to log in to their account.
• Relative goals: These are the goals with relative quantification. The goals are evaluated based on comparative analysis with other products, platforms, versions, or processes that perform the same task. For example, on a new version of a social media account, users should take less time to log in than on the previous version.

There is another classification of quantitative usability goals based on the element that is being quantified.

• Performance goals: These goals focus on quantifying user performance. Performance is measured in terms of time taken and errors made by the user to perform a task. For example, all the examples of quantitative usability goals we have seen so far can be termed as performance goals.
• Preference goals: These goals focus on the users’ preference between alternative interface options based on the users experience. For example, users of a particular application prefer to read text with 50 characters per line. Even though the readability is best with 100 characters per line, this identified goal has importance and will be considered along with performance goals.
• Satisfaction goals: These goals focus on user satisfaction with an interface. Satisfaction goals are subjective, unlike all other quantitative goals. For example, they can be measured on a scale of 1 to 5, with 1 corresponding to least satisfaction and 5 to most satisfaction.

Sample technique

This is a step-by-step guide to be followed while setting usability goals. The steps in this technique are as follows:

1. Refer to the user profile: In most cases, a large number of usability goals get identified in user profiling. User profiling helps to identify the relative importance of ease-of-use and ease-of-learning goals, and the relative importance of performance, preference, and satisfaction goals.
   For example, if user profiling results reveal that a major portion of the user group is experienced within the Microsoft Windows interface, the goal would be to prefer performance over preference and satisfaction and design a system with an interface similar to Microsoft Windows. On the other hand, if a major group of users is interested in new systems, then preference and satisfaction goals will also be considered along with performance goals.

2. Refer to the contextual task analysis: Contextual task analysis can suggest usability information regarding work environment and context. It also identifies key user tasks and actors that can help to determine the time and work related quantitative goals. For example, on social media accounts, users can change their passwords anytime. Contextual task analysis may reveal that this task is a frequent use case. So, an ease-of-use goal may be set as “after updating a password twice, a user should not take more than 30 seconds to navigate to the correct screen and update password.”

3. Research business goals: Interface design goals are usually based on business goals. Therefore, identifying business goals can help to identify usability goals. For example, the business goals of an e-store can be to increase sales and to decrease customer support, training, and documentation expenses. These business goals can be a base to design interface goals for a good interface. Usability goals like “a novice user should not take more than 20 seconds to find the relevant product category in the menu,” or “the system should not take more than 5 seconds to load the search results” can help to assure a smooth user experience and thus achieve business goals as a result.

4. Identify and draft qualitative usability goals: Many qualitative usability goals will be identified when performing steps 1, 2, and 3. It is good practice to document the goal as soon as it is identified.

5. Prioritize usability goals: Based on steps 1, 2, and 3, prioritize usability goals. The goals can be categorized as the most important (necessary for the overall success of the project), a bit important, and nice to have (not crucial for the project).

6. Document prioritized usability goals: Document the goals prioritized in the previous step.

7. User/management review: Get users’ and management’s feedback on the documented goals. Incorporate any changes suggested and make necessary updates.

8. Establish benchmark data: After the goals have been finalized, the last step is benchmarking. Potential competitors’ data is collected and analyzed regarding usability goals and processes. The purpose here is to have an idea on how to design better interfaces by comparing products and their benchmark data.