Testing a prototype is a crucial step in the product development process. A prototype is an early sample or model built to test a concept or process (Rouse, 2015). It serves as a preliminary version of a product, allowing developers to evaluate its design, functionality, and potential flaws before finalizing the design and moving into production.

But what are the different types/stages of prototypes? How does a prototype relate to, for example, a Proof of Concept, Minimum Viable Product (MVP) and the final product? This blog will answer these questions. If you’d like to read it in another language, simply click on the flag below this post, and the text will be translated into your preferred language.

Testing a prototype

Testing a prototype is a crucial step in the product development process. A prototype is an early sample or model built to test a concept or process (Rouse, 2015). It serves as a preliminary version of a product, allowing developers to evaluate its design, functionality, and potential flaws before finalizing the design and moving into production.

The primary goal of prototype testing is to identify and address any issues or shortcomings early in the development cycle, when making changes is relatively inexpensive and straightforward (Liedtka, 2015). By testing the prototype, developers can gather valuable feedback from potential users, stakeholders, and experts, which can inform necessary modifications or improvements. More information about testing can be found here.

Types/stages of prototypes

There are various types of prototypes, ranging from Low-Fidelity (e.g., paper prototypes, wireframes), Middle-Fidelity, to High-Fidelity (e.g., functional models, beta versions; Interaction Design Foundation, n.d.). Addressing this various types of prototype testing is crucial, especially considering that these different types often correspond to distinct stages of development. It’s not merely about testing prototypes; rather, it involves navigating through the progression of prototype testing stages. Each stage serves a specific purpose, from low-fidelity prototypes providing a preliminary glimpse into the concept’s feasibility to high-fidelity prototypes refining intricate details before moving towards production. Understanding these stages illuminates the iterative nature of product development, where each iteration informs the next, ultimately leading to the creation of a refined and viable final product.

Here is more information included about these stages of prototype fidelity:

• Low-Fidelity Prototypes are simple, inexpensive representations of a product or system that are used to test and evaluate basic concepts and functionality. They are typically created using paper, cardboard, or basic digital tools, and lack the look, feel, and interactivity of the final product (Usability.gov, n.d.). Low-fidelity prototypes are useful in the early stages of design, as they allow for rapid iteration and feedback without significant investment of time and resources. Its primary aim? Its to explore and communicate design ideas (Walker, Takayama, & Landay, 2002), allowing for rapid iteration and feedback on the usability and user interaction aspects without getting entangled in the technical complexities.
• Middle-Fidelity Prototypes are more refined than low-fidelity prototypes, but still lack the full functionality and polish of the final product. They may include basic interactivity, visual design elements, and more detailed representations of the user interface (Interaction Design Foundation, n.d.). Middle-fidelity prototypes are often used to test and refine specific features, interactions, and design decisions before committing to the development of a high-fidelity prototype or final product.
• High-Fidelity (Hi-Fi) Prototypes are highly detailed and interactive representations of the final product or system. They are typically created using specialized software or development tools and closely resemble the look, feel, and functionality of the final product (Usability.gov, n.d.). High-fidelity prototypes are used to test and validate the complete user experience, identify and address any remaining issues, and gather feedback from stakeholders and potential users before final development and deployment.

The choice of prototype type and fidelity stage depends on factors such as the stage of development, the complexity of the product, and the specific aspects being tested.

In practice, however, it’s common for teams to start with low-fidelity prototypes and work their way up to high-fidelity versions as they develop and iterate their ideas. This iterative process involves repeatedly testing and refining prototypes based on user feedback and insights gained throughout the development journey. Beginning with low-fidelity prototypes allows teams to quickly explore and validate different design concepts without investing significant time and resources. As the project progresses and more details are solidified, teams transition to high-fidelity prototypes, which provide a more realistic representation of the final product. This gradual refinement helps ensure that the final product meets user needs and expectations while minimizing the risk of costly design changes later in the development process.

Examples of each stage

Imagine you’re an inventor, solving the world’s mysteries one prototype at a time. You’d go through different stages of your creation, starting from the simplest form—like a drawing—to the most complex version—that feels like the real thing. Let’s now walk through all these stages.

Low-Fidelity Prototypes: This is basically your invention’s idea in its earliest, simplest form. Imagine drawing a bicycle on a piece of paper—that’s a low-fidelity prototype.

• Example 1: Sketching a new app on paper. This might only show where the buttons go on each screen, but it’s a start!
• Example 2: A cardboard model of a new toy. It might not have all the colors and moving parts yet, but you can start to see its shape and size.
• Example 3: Using sticky notes to plan how a website will look. Each note can represent a different part of the website and can be moved around to determine the best layout.

Middle-Fidelity Prototypes: Next, you’ll add more detail to your invention, but it still might not work exactly like the real thing.

• Example 1: A clickable prototype of an app made with a tool like PowerPoint. Here you can simulate what happens when you press each button, even if it doesn’t have all the fancy graphics and animations yet.
• Example 2: A 3D-printed model of a new toy. Now you’ve got a physical object that’s closer to the real size and shape, but it might still be missing color and functionality.
• Example 3: Mockups of a website using a design tool. Now you can see more detail like colors, fonts, and images, but you can’t interact with it like a real website.

High-Fidelity Prototypes: Finally, you’ve got a version of your invention that feels almost like the real thing.

• Example 1: An interactive prototype of an app made with a specialized tool like Figma or Sketch. Now when you tap a button, the right thing happens—you open a new screen, play a sound, or see an animation.
• Example 2: A detailed and functional prototype of a toy made with the same materials as the final product. It now looks and feels like the real thing and has all the working parts.
• Example 3: An interactive prototype of a website using HTML, CSS, and JavaScript. It looks and functions like the final website, but it’s not live on the internet yet.

Keep in mind, every inventor—from toy creators to app developers—uses these steps to make their ideas come alive. Remember, it’s not about getting it perfect right away, but about learning and improving as you go along.

Additional information

Prototype testing typically involves a combination of methods, including:

• User testing: Observing and gathering feedback from representative users as they interact with the prototype in a controlled environment (Usability.gov, n.d.).
• Expert evaluation: Soliciting input and critique from subject matter experts, engineers, or designers who can identify potential issues or areas for improvement (Usability.gov, n.d.).
• Technical testing: Evaluating the prototype’s performance, reliability, and compatibility with existing systems or infrastructure (Rouse, 2015).

The insights gained from prototype testing can lead to refinements in design, functionality, usability, or even a complete rethinking of the product concept if significant issues are identified (Liedtka, 2015). This iterative process of prototyping, testing, and refining helps to mitigate risks, reduce development costs, and increase the likelihood of delivering a successful product that meets user needs and expectations.

Note that it’s always very important to test prototypes and, during testing, to evaluate them based on known requirements. You can find more information about testing here. Also, read this article about the Experience Prototyping testing method.

I will soon include more information about the entire journey from idea to delivery, which will also cover prototype testing in detail. Keep an eye on my blog, as more posts on this subject will follow.

The Non-Linear nature of development

It is important to keep in mind that progress in the field of development and testing is not necessarily linear, it’s a continuous cycle of improvement and adaptation (Hoda, Noble, & Marshall, 2012).

Let’s look at requirements as an illustration. They may dynamically change, expanding longer, more complex, or more streamlined in response to the results of testing phases. This is why careful documentation of your findings holds immense value. By carefully recording and explaining your observations, you provide clarity to others, helping them understand the rationale behind specific decisions.

You can find further information about the requirements here.

Understanding the Differences: Prototype, Proof of Concept, MVP and Final Product

Remember, a prototype, a Proof of Concept (PoC), Minimum Viable Product (MVP) and a final product are not the same things.

• A Proof of Concept (PoC) confirms the feasibility of an idea.
• A Prototype transforms an idea into a tangible experience to test its practicality and user interaction.
• Minimum Viable Product (MVP) offers an opportunity to test whether the product is truly needed and can deliver value and profit before mass production of the final product begins.
• Final Product brings the fully developed concept to life, introducing it as a complete and market-ready entity (Nielsen Norman Group; Harvard Business Review).

You can read more information about the differences and connections between Prototype, Proof of Concept, Minimum Viable Product and the Final Product here. Additionally, this article also discusses the relationship between high-fidelity prototypes and the final product, and many other things.

Sources:

• Gov. (n.d.). Prototyping. Retrieved from https://www.usability.gov/what-and-why/prototyping.html
• Gov. (n.d.). User experience evaluation methods. https://www.usability.gov/how-to-and-tools/methods/index.html
• Harvard Business Review, https://hbr.org
• Hoda, R., Noble, J., & Marshall, S. (2012). Developing a grounded theory to explain the practices of self-organizing Agile teams. Empirical Software Engineering, 17(6), 609-639. https://doi.org/10.1007/s10664-011-9181-0
• Interaction Design Foundation. (n.d.). Prototyping: Learn the basics. https://www.interaction-design.org/literature/topics/prototyping
• Interaction Design Foundation. (n.d.). Prototyping: Learn the Fundamentals of Prototyping. Retrieved from https://www.interaction-design.org/literature/topics/prototyping
• Liedtka, J. (2015). Evaluating prototypes. In Design thinking for the greater good: Innovation in the social sector (pp. 115-132). Columbia University Press.
• Nielsen Norman Group, “When to Use Which User-Experience Research Methods”, https://www.nngroup.com/articles/prototype-fidelity
• Rouse, M. (2015, April). Prototype. SearchSoftwareQuality. https://searchsoftwarequality.techtarget.com/definition/prototype