Understanding Web Usability and Evaluation

Apart from user design, the other aspect which is key to any web-development effort is its usability. As discussed earlier, usability is about executing web transactions effectively and making sure that users are satisfied with their interactions and find the web experience, easy, intuitive, and relevant. Usability evaluation is typically performed as an extension to the testing phase of an application software life-cycle with the aim of verifying the web application against specific usability requirements.

The definition of usability as a part of ISO 9241-11 standards is “The extent to which a product can be used by specific users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use.” In his book Usability Engineering, Jacob Nielsen suggests five qualities of a usable product.

1. Learnability: It is the ease of learning functionality and behavior of the system.
2. Efficiency: It refers to the level of attainable productivity once the user has learned the system.
3. Memorability: It denotes the ease of remembering the system functionality on the next return.
4. Few errors: It is the capability of a system to feature a low-error rate.
5. User’s satisfaction: It refers to the measure in which the user finds the system pleasant to use.

Apart from these, Whitney Quesenbery has shared a set of 5Es to usability as follows:

1. Effective: It denotes the completeness and accuracy with which users achieve their goals.
2. Efficient: It is the speed with which users complete their tasks.
3. Engaging: It includes how pleasant, satisfying, or interesting an interface is to use.
4. Error tolerant: It involves how well the product prevents and recovers users from errors.
5. Easy to learn: It supports initial orientation and continued learning of the product.

It has to be noted here that although all five Es are important for usability, not all of them might be equally important in a particular scenario or for a specific project. The balance among the 5Es, thus, would depend on the prominence of feature and the type of stakeholder which is using that product. For example, for an e-commerce site selling products, efficiency and effectiveness could be most important, while for a site which is high on interactive educational learning, engaging and easy-to-learn attributes might be more important.

Thus, usability has to be analyzed and developed with a strong understanding of the specific situation and type of users at hand. Once firms have developed the requisite usability elements and incorporated them into the website, it is important that designers evaluate whether their final web product meets the required level of usability. We would need to develop an understanding of the concepts of usability evaluation to test if the application actually meets stated user requirements.