Principles of good interface design

When your clients mistakenly click, ask again, or leave a page midway, their first reaction is often "it needs to be redone to look better." But in most cases, the issue is not aesthetic. The problem is that the interface violates some underlying principle that makes clients unsure of where they are, whether the system has received their command, or what the next step is. There is a set of proven principles to correctly identify those areas.

The fundamental principles you need to know.

Jakob Nielsen, a Danish usability researcher (usability: the ease of use of a product), formulated ten heuristic principles in 1994 and updated them in 2020. These are not hard laws but rather broad experience-based rules applicable to all types of interfaces, from websites to mobile applications, as they are built on human behavior rather than technology. Sinh Vũ uses this set as a mandatory checklist before discussing any aesthetic decisions.

Among those ten principles, there are four that Sinh Vũ frequently sees violated in practice when working with Vietnamese clients:

• Visibility of system status: customers must always know what is happening. If they press a button with no feedback, they will press it again, multiple times, or think the page is malfunctioning.
• Recognize rather than remember: present options clearly, do not make clients remember information from previous steps to use in the next.
• Prevent errors and allow for backtracking: designed to make it difficult for customers to make mistakes, and to correct them if they do. Not having a "back" or "cancel" button is a design flaw, not a minimalist choice.
• Aesthetic and minimalism: every unnecessary element is not only useless but also dilutes the truly essential elements. Adding something to the screen means taking away some attention from other things.

Jakob's law and the concept of familiarity

One of the most important principles that Sinh Vũ sees many businesses overlook is Jakob's Law of Internet User Experience. The content: clients spend most of their online time on other sites, not yours. Therefore, they bring all their expectations formed elsewhere to your site.

Practical conclusion: the more the interface adheres to familiar conventions, the less customers have to learn and the quicker they feel confident. This does not mean it has to be identical to competitors. Brand differentiation should lie in content, tone, color, and emotion. As for menu placement, call-to-action button layout, and status display: these should follow industry conventions, not be areas for creativity.

Aesthetic and easy to use: do not choose one

You need an additional nuance: research from the Nielsen Norman Group notes the aesthetic-usability effect, meaning that a beautiful interface is often perceived by users as easier to use, even if that is not necessarily the case. This means that aesthetics are important, but they should not replace usability. Both must be present simultaneously.

Clients spend most of their time on other pages. They want your page to function like the ones they already know.

Jakob Nielsen, Nielsen Norman Group

Common mistakes when designing interfaces

• Prioritize uniqueness over clarity: break familiar conventions to appear different, forcing customers to relearn how to use things that already have established standards.
• No response when customers interact: Pressing buttons does nothing, page loading has no progress indicator, submitting forms has no confirmation. Customers are left guessing and lose trust.
• Evenly distribute everything with the same prominence: when nothing is truly more prominent, customers do not know where to look first or what the next step is.
• Applying mechanical principles without understanding why: copying heuristics from blogs without understanding the context leads to using them inappropriately. For example, "minimalism" does not mean removing all labels and using only icons, as icons alone are often not clear enough for the majority of users.

The viewpoint of Sinh Vũ

Sinh Vũ considers usability principles as a mandatory foundation that must be completed before discussing brand identity and emotional resonance on screen. Specifically, Sinh Vũ's design process starts with content strategy and experience flow based on how customers make decisions, then moves to wireframes, and finally to the complete interface. This order is crucial and should not be reversed.

Visual hierarchy is also something Sinh Vũ pays special attention to: the most important elements must stand out the most. Not evenly distributed. A screen where everything is equally large, bold, and colored essentially has nothing important, and customers will sense that even if they cannot articulate it.