Usability Testing, Field Studies and Analytical Evaluation
Evaluation is a very important component of the design process. From the user’s point of view, evaluation is needed to see if the product meets their needs. Although, usability of the design is one of the concerns of a user, other factors are also considered by them. They must also be engage in the product and the degree of sophistication the product gives them. In a businessman’s or manufacturer’s point of view evaluation is needed to get feedback from the user to be able to further improve their product. (Sharp, Rogers & Preece, 2007)
Almost all products, either interactive or not should be evaluated based on its features. For example, websites can be evaluated based on its functionality while other software tools can be evaluated if users find its features engaging. Evaluation made using different ways like inside laboratories or creation of natural set-ups like actual usage of the products of the intended users and observation of their actions towards it. The time of evaluation depends on the kind of product. Some needs to undergo several stages of evaluation and through different versions. (Sharp, Rogers & Preece, 2007)
Three main approaches of evaluation are usually implemented. These are usability testing, field studies and analytical evaluation. These three approaches use several methods of evaluation like observation of users, conducting interviews to both users and experts or modeling user performance. (Sharp, Rogers & Preece, 2007) Usability testing is the most commonly used type of evaluation. This type of testing involves the identification of usability problems, collection of quantitative data on the user’s performance like noting the length of time it takes to finish a task and noting the rate of errors the user commits when using the product and determining the overall user satisfaction of the product. Its main goal is to test if the product can be used by the intended user to the task in which the product is designed for. Interviews and questionnaires can also be floated to know user’s judgment. The environment used by the evaluator is a controlled environment where the evaluator is guided by an evaluation plan. For example, usability testing for websites identifies any functional problems that may occur in the website that may prevent visitors from getting the information they need or passing information to the company. Basic things to be tested would be navigation and functionality of links. An expert can be tapped to navigate the website and make him answer some prepared questionnaires afterwards or be interviewed regarding his experience with the website.
Field study on the other hand, is a type of evaluation where natural setting is used to gather the necessary information. It is usually done to find out how a specific product or prototype is being used by the users in their daily lives or work environment. The evaluator does not have influence of the outcome of the study. Observation and interview are the main methods of collecting data about the users, user needs and product requirements. Observations can either be done directly or indirectly. This type of evaluation allows the evaluator to have a view of what the user will actually do when the product is released or when the prototype is implemented. (Sharp, Rogers & Preece, 2007) For example, if a new gadget would be released that is designed for use in an office, company can invest on evaluating how the new gadget is used by its intended users by observing either directly or indirectly how they behave with the gadget. Sometimes, evaluators prefer to use indirect observation so the users will be conscious of their observers.
Analytical evaluation involves the use of to common methods, inspection or the use of theoretically based models. Inspections can either be in the form of heuristic evaluation or walkthroughs. Heuristic evaluation involves having a small set of evaluators to examine and identify usability problems vis- a – vis a standard or recognized usability principles. It is like checking if a specific product has all the features found in a checklist intended for the purpose. Walkthrough on the other hand, involves showing prototypes of the product to a group of experts for their evaluation. Using theoretically based models for evaluation involves the use of existing models to evaluate the product. (Sharp, Rogers & Preece, 2007)
The role of the users in usability testing is to carry out a set of tasks, while in field studies, users are expected to show their natural behavior, however, users are not involved in analytical evaluations. In terms of location and control, usability testing’s is done in a laboratory controlled by the evaluator and uses with a prototype or a product, field study is done in a natural environment where evaluators try to forge relationship with users and done on early stages of the design to ensure that user requirements are met and analytical evaluations are done by expert evaluators with a prototype either in a laboratory or within the customer’s premises at any stage of the development. Usability testing and analytical evaluations uses quantitative data for evaluation while field studies uses qualitative data accompanied by sketches, scenarios or artifacts. The method to be used for evaluation depends on the developer or the manufacturer and its applicability. Sometimes, evaluators combined different approaches to get the best result. If applicable, a company can use all three methods of evaluation.
References:
Sharp, Helen, Rogers, Yvonne & Preece, Jenny (2007). Interaction Design: Beyond Human-Computer Interaction 2nd Edition. Retrieved from http://books.google.com.ph/books?id=xEiz4PhwE9gC&dq=interaction+design+beyond&hl=tl&sa=X&ei=UydpT_eAIo2ZiQfMhYy8Cg&ved=0CDUQ6AEwAQ
