Common practical mistakes

Most usability issues do not stem from a lack of features. They arise from forcing customers to think too much, perform too many steps, or not knowing what the next step is. Identifying these early saves a lot of effort in fixing them after launch.

Why are usability errors often overlooked?

Website builders are often too familiar with their product. They know where the menu is, which fields are mandatory, and what each button does, so they do not perceive the stumbling blocks that new customers encounter. Usability issues often only become apparent when an outsider interacts with it or when behavioral data shows that customers abruptly leave the page at a specific step. The good news is that most of these errors can be detected through a small observation session, without needing a large-scale survey.

The seven most common mistakes

• Navigate using internal language. Menu names should reflect how the company refers to them internally rather than how customers think. Customers visiting the page may not understand which section leads to what they need, leaving the page instead of exploring further.
• The menu has too many items at the same level. When everything stands out, nothing truly stands out. Customers spend time scanning everything instead of going straight to their goal.
• Forms that ask too much, vague error messages. Each additional field is a reason for clients to stop. Error messages like "Invalid information" do not help clients know what to correct.
• No feedback after actions. When a customer clicks the send button and sees no changes, they don't know if the system has received it. The result is multiple clicks, duplicate submissions, or simply a loss of trust.
• Many equal call-to-action buttons. When three or four buttons of the same size and color appear on a page, none of them truly guide the user. Customers hesitate and often do not click any button.
• Difficult-to-read text. Small font size, light text color on a bright background, overly long lines, or cramped line spacing create friction when reading, especially on mobile devices.
• Touch area on mobile is too small or too close together. Fingers are not as precise as a mouse pointer. Small buttons placed close together lead to misclicks, causing frustration and loss of trust in the interface.

The error-checking framework: ten principles of experience

Nielsen Norman Group outlines ten usability heuristics for evaluating interfaces without user testing. You can use this list to self-review each important screen:

• Display system status: do clients know what is happening?
• Align with the real world: is the language and symbolism familiar to the clients?
• Allow clients to control and exit: is there a clear exit strategy if clients accidentally overspend?
• Consistency and standards: do the same actions yield the same results everywhere?
• Prevent errors before they occur: does the interface guide clients to avoid incorrect entries?
• Realizing instead of having to remember: does the customer need to retain information from the previous step?
• Flexible and effective: do users have shortcuts they are accustomed to?
• Minimalism: is there anything unnecessary on each page?
• Help customers understand and address errors: does the error message explain how to fix it?
• Is there assistance available when needed: do customers know where to seek support?

Most usability issues reveal themselves during the first round of testing with five people. No large data is needed to find them; just observe real users in action.

Nielsen Norman Group, "Why You Only Need to Test with 5 Users"

Edit in order of priority

The viewpoint of Sinh Vũ

Sinh Vũ approaches from the experience flow, not from individual pages. This means that most usability errors are blocked right from the structure and wireframe stage (the layout sketch before detailed design): each page defines a primary action, the call-to-action button stands alone and is clear, and forms only ask what is truly necessary at that step.

The error of internal language being hard to understand is addressed in the content writing stage: the wording on the interface should reflect how customers speak, not how the operations team refers to it internally. For Sinh Vũ, the goal is not to reduce errors by a percentage but to ensure each page has a clear path from entry point to action.