The laws of HCI design are not as strict as other kinds of laws. They're really fuzzy actually. The two most famous are Fitt's law & Hick's law. Both of them are based on the theory of information. That's a quite solid foundation and the laws "make sense". Recently I've learned about a new one - "SNARC effect". Apparently it was discovered in the 90s and is still under active research. Google it - it's quite an interesting one! And nobody quite knows why it occurs. There is no underlying theory. For some individuals it may appear, disappear or even reverse - but for groups it's reliably present. It happens in people, chickens and even bees - but for some reason not so much in professional mathematicians. Interestingly (but not surprisingly) it also goes against some of the established programming terminology like "shift left" / "shift right" to multiply / divide number by 2. What really makes this interesting for me is the source of the effect. That's still a mystery but I think that once it's nailed down, it'll lead to a bunch of other, related effects, that could be exploited in UI design!

All three are very interesting!

First time hearing about SNARC! fascinating. We count on our hands left to right too.

Oh, weird. I’ve never heard of snarc before - thanks for mentioning it! A few moments bouncing this off of an LLM (Perplexity in this case) results in: Forth and APL syntax is preferred over Lisp syntax, both are preferred over infix. Data on which side of the road to drive on totally contradicts snarc prediction. Snarc does not seem to be a big enough factor in our (western) cultural choice of representing numbers with most significant digits on the left. I read Raskin’s “Humane Interface” a long time ago. Apparently he mentions Fitt’s and Hick’s laws in chapter 4. Snarc was discovered after Raskin’s book. Apparently, snarc validates Raskin’s claims.

Cognitive HCI theories go beyond this, if you're willing to admit things that aren't behavioral "laws" with well-defined numbers. For example, Information Foraging describes how people engage with graph-like information environments and is pretty well-established and has been found to apply in many contexts (reading code, browsing the web, skimming search engine results, searching wikis, etc.). This gives an answer to questions like "Why is it helpful that Google's search results page includes excerpts from the pages?" The answer is that it helps provide a stronger "information scent".

Worth mentioning https://lawsofux.com/