How UI Design Elements Affect Fluency & Memory for Text-Based Information

The Question

My senior thesis asked a question I keep returning to: when text is presented through different design decisions, what do those decisions do to how it's understood and remembered?

The experiment manipulated four UI variables — font size, font style, color palette, and layout — and measured their effects on two cognitive outcomes: processing fluency, how easily a reader takes the text in, and memory retention, how much they could recall afterward.

What I Found

The findings were less binary than I expected, and the asymmetry mattered.

Layout was the only variable with a consistent independent effect. Layouts structured according to Gestalt principles — clean proximity, alignment, and visual hierarchy — produced significantly better fluency and recall than disorganized layouts.

Font size, font style, and color palette didn't behave the same way. Their influence depended on the visual context they appeared in. They worked as a system rather than as independent levers — a typographic choice that aided fluency in one layout could undermine it in another.

The takeaway wasn't that some variables matter and others don't. It was that they don't operate on the same level. Layout sits upstream; type and color sit downstream of how the eye has already been oriented.

What It Taught Me

These findings shape how I've approached design since. I work upstream of the interface before I work on it — at the level of how something is organized in the eye and the mind before what it looks like. The thesis was the first time I had evidence for what I now treat as a working principle: cognitive load isn't a styling problem, and the smartest design decision is usually the one made before any aesthetic choice gets locked in.