This article is part of a series that examines human factors testing in different contexts. This article looks at usability risks and sample size requirements. We also discuss the benefits and drawbacks of human factors testing. It includes additional resources related to human factors testing in research and development. Finally, we highlight important factors to consider when evaluating your research.

Usability

Usability as human factors formative study evaluates how well a product or service works for its intended users. Researchers may use formative or summative evaluations to learn more about the subject matter during this exploratory phase. The goal of usability research is to improve the design and development of a product. There are two main types of usability research: usability engineering and balance innovation and design. Both use a human-centered approach to product design.

Medical device manufacturers are adept at developing new technologies and navigating regulatory processes. The draft guidance from the Food and Drug Administration (FDA) provides insight into regulators’ thinking and the application of existing standards and reference documents. The guidance is not legally binding, but it does give the manufacturers a helpful guideline for ensuring the usability of their products. Nevertheless, medical device manufacturers should not try to go it alone without the assistance of usability professionals.

Hazards

Human factors form the foundation of a product’s development process. Formative user evaluations can identify possible errors and unanticipated use scenarios. These studies can also help improve the design of a product before submission to the FDA. Furthermore, the results of a human factors formative study can guide future product development and design, including instructions and packaging. Here are some hazards of human factors in formative studies. Listed below are some examples of these types of studies.

Constrained budgets and time often prevent human factors evaluations during this phase. For this reason, it is imperative to start early in the development process. During the development process, a human factors consultant should work closely with the device developers to determine what improvements are needed. Working together, they can produce a safer and more usable product. If you cannot hire a human factors consultant, consider working with a product developer instead.

Sample size requirements

Sample size requirements for human factors formative studies vary based on the type of study. For example, FDA human factors guidance calls for a sample size of fifteen participants for a usability study, but some experts argue for less. A usability study should also be designed to mimic the real-life setting as closely as possible. In this article, we’ll review how sample size requirements for human factors formative studies can be determined.

A formative human factors formative study is very similar to a validation study. Researchers recruit a representative group of users of the product and then introduce it to them in a way that mimics how they would use it. Typically, a commercial product is released with a training process. In a formative study, users learn about the product by interacting with it and reviewing the information. In contrast, clinical trials aim to prevent interference with data collection by ensuring that the sample is representative of actual users.

UI changes in response to formative study findings

A user-centered design process involves two main types of evaluation: summative and formative. Summative evaluations are used to evaluate a shipped product and track its overall usability. Formative evaluations reveal what works well in a design and what needs improvement. In addition, the formative assessment shows how well the final product compares to competitors. This article discusses the differences between the two types of evaluation.

A human factors evaluation involves surveying to gather user feedback. The human factors formative study is conducted either live or behind a one-way mirror. The primary purpose of a formative assessment is to gather input and meet FDA expectations. During the evaluation, participants reported which UI changes were most helpful. The results of the constructive reviews may lead to significant changes in the design. Moreover, formative evaluations also help identify issues that require substantial changes to the UI.