Can aesthetics in product design be measured?

During my interview at DomClick, I spoke with the design director and the CPO. We ended up having a long but fascinating discussion about how to define what makes a product design truly great—not in terms of usability metrics, but specifically regarding visual language. This topic is still a hot one in product teams, so I’d like to share my perspective.

My approach is quite pragmatic: I believe in separating concerns. A brand should be evaluated through the lens of visual language, emotion, and tone of communication. An interface, on the other hand, should be evaluated through the lens of how easily it helps users complete tasks.

Why?

An interface is a dynamic object. It's something users interact with. They take action, and the system responds—changing an element’s state, giving feedback, showing an error, etc. Because of this, every visual element in an interface exists to make that interaction smoother. Color affects how quickly users identify visual cues. Typography affects how fast they can read and understand content. Composition affects visual hierarchy and, consequently, how fast they can find what they’re looking for.

Emotions—positive or negative—are driven by how fast and easily a user can complete their task. If you try to test aesthetics in the context of an interface, the data won’t be relevant: users focus on different things.

Visual language is tested through emotional perception, and that’s best collected from static objects. Take a graphic poster, for example—the only form of interaction is visual. We evaluate whether the geometry, tone, letterforms, color palette, or illustration style resonate with us. The focus is not on task completion, but on what we feel internally—in short, emotion.

The Core Idea:

The interface should inherit the brand’s aesthetic—but it shouldn’t define it. Each object should have its own evaluation metric. As mentioned: for brand—emotions; for interface—task efficiency. This kind of separation gives you cleaner, more relevant insights to guide product design decisions.