Prototyping is an important step in the design and development process. A prototype can be described as an early sample, model, or version of a product that is built in order to test a concept or process. It is typically used to validate a product’s design and functionality and to gather feedback from potential users before investing in mass production. In addition, prototypes help define the specifications and requirements for the final product (Arena, 2026). Because of this, prototyping often serves as a valuable starting point for projects that aim to create digital or physical products.

Within the field of design, prototypes are commonly categorized into three different stages: low, medium, and high fidelity. In this context, the term fidelity refers to the level of detail, accuracy, and realism of a prototype in comparison to the final product (Sorodoc, 2025). A low-fidelity prototype is intended to provide a rough representation of an idea and to communicate the basic concept of a product. These prototypes are usually simple, inexpensive, and quick to produce, which allows designers to visualize ideas and gather early feedback without the risk of significant costs.

Medium-fidelity prototypes contain more accurate and detailed elements and begin to demonstrate specific functions and interactions. At this stage, the prototype offers a clearer impression of how the product might look and behave, making it suitable for more structured user testing and feedback.

High-fidelity prototypes represent the stage closest to the final product. They contain a high level of visual detail and interactive elements and allow realistic testing before final production decisions are made. Due to their complexity, these prototypes typically require the greatest investment of time and resources.

The current research project focuses on user experience design at German train stations and investigates how the experience on train platforms could be improved for passengers. After examining the theoretical background of this topic over the past six months and building a solid foundation of knowledge about the relevant parameters, design considerations, and possible approaches, it is now a logical next step to move toward more practical exploration. Prototyping offers the opportunity to translate theoretical insights into tangible experiments and to explore how the project’s ideas could be implemented in practice.

Low fidelity prototype

To explore this practical dimension, three different low-fidelity prototypes were conceptualized and developed. Each prototype approaches the same problem from a slightly different perspective while using different materials and forms of interaction. The first prototype was created as a paper prototype, which is a simple yet effective method for developing an early representation of an idea using inexpensive and easily accessible materials. Paper prototyping allows designers to test concepts quickly and to discard or modify them easily while still gathering useful insights and feedback (msg, 2026). For this prototype, a sketch of a train platform was created to represent the situation of a train arriving at a station. Participants were asked to place circles representing different passenger groups on the platform drawing. The task was to indicate where they believed these users would position themselves in order to board the train. This exercise aims to identify whether there are recognizable patterns in passenger placement and whether the current signage and orientation systems on train platforms provide enough information for users to intuitively position themselves.

The second prototype also uses paper as the main material but aims to create a more interactive and flexible representation of the scenario. In this version, a simple model of a train platform was built that includes small figures representing passengers. Participants can move these figures around the platform in order to simulate their behavior when a train arrives. Similar to the first prototype, the central question concerns the positioning of passengers and the information they might need to find an optimal location for boarding. After completing the task, participants are invited to draw directly on the prototype to indicate where additional signage, markings, or guidance systems could improve the clarity and usability of the platform. This approach allows users not only to demonstrate their behavior but also to actively propose potential design improvements.

The third low-fidelity prototype explores a digital approach instead of a physical one. For this prototype, the collaborative digital workspace Miro was used. Miro functions as an online whiteboard that allows multiple users to interact with visual elements in a shared digital environment (Miro, 2026). Within this digital workspace, a simplified representation of a train platform was created. Participants join the Miro board and are asked to place themselves within the platform layout in the position where they would choose to wait for an approaching train. After this initial round, participants are allowed to add visual guidance elements such as lines, colors, signs, or other indicators that they believe would help clarify where passengers should stand. Once these elements have been added, the task is repeated so that the results can be compared, and it can be observed whether the additional guidance elements improve user behavior and decision-making.

Those three prototype will be tested and the results and observations will be evaluated to see whether one of the approaches could be beneficial and whether one of the prototypes has the potential for further improvement.

Information gathered

Exploring these different prototyping approaches has provided a deeper understanding of the role prototypes play in the design process. Prototypes are not only useful for testing digital interfaces but can also be applied to spatial and physical interaction scenarios such as those found in public transportation environments. Through the upcoming testing phase, valuable insights are expected to emerge regarding how passengers interpret spatial information on train platforms and which design interventions could help improve clarity and usability. These findings will contribute to the broader investigation of user experience design in railway environments.

Next Steps

The next step in the project will involve testing the three prototypes with participants in order to gather feedback and behavioural observations. The collected information will then be analysed to determine whether one of the approaches proves particularly effective and whether any of the prototypes show potential for further development. Based on the insights gained during this phase, the most promising concept may be refined and further developed into a medium-fidelity prototype that allows for more detailed testing and continued exploration of improved user experience design solutions for train platforms.

Reference

Arena. (2026). What is a Prototype? Von Arena: https://www.arenasolutions.com/resources/glossary/prototype/ abgerufen

Miro. (2026). Von Miro: https://miro.com/de/ abgerufen

msg. (2026). Paper prototype. Von User Experience Methods Catalogue: https://user-experience-methods.com/en/04_design/paper-prototype.html abgerufen

Sorodoc, I. (11. March 2025). Low-Fidelity vs. High-Fidelity Prototyping: Key Differences Explained. Von ProtoPie: https://www.protopie.io/blog/low-fidelity-vs-high-fidelity-prototyping abgerufen