What does simplicity actually mean?
I haven't yet read any formal definitions, but here are some early thoughts on what I think it might mean.
One might think that simplicity might be synonymous with minimalism.
However, I'm not sure that's the case. I also don't define minimalism to mean anything other than good use of white space, reducing noise, and using more elements than is needed. I've seen sites that are minimalist.
But I think simplicity has an added touch.
Simplicity has an element of elegance to it. It evokes a real effect on the user or audience.
I was designing a screen. It didn't have a whole lot of text. Probably could fit the definition of minimalist. I actually added an icon to the interface (rather than taking something away) and it made the interface feel lighter. My brain actually felt like weights had been taken off of it.
Then I replaced one line of text with two icons. (Sounds kind of odd without giving you the context.) Again, also adding more things (while taking away one line of text).
Amazingly, I could comprehend the interface faster. I put the two screens side by side, and the difference was astounding. When I looked at the revised interface, it was hard to describe what I was experiencing.
But it felt simple. And that was enough for me.
Could simplicity in fact be a feeling?