Colour naming experiment

Firstly, sorry for the delay in getting a new proof written. I’ve been travelling, and then got sick on the flight home and was mostly incapacitated for two weeks. And I have deadlines for other stuff that then got in the way.

But one of those deadlines also involves science, and it’s pretty cool so I thought I’d share it with you. I do volunteer work with CSIRO’s STEM Professional in Schools program. As a professional scientist, I am partnered with a primary school and visit the school several times a year to talk to and engage the students with science topics. In past years I’ve mostly done presentations and Q&A sessions, but this year the school science coordinator suggested running a science club with some of the keenest science students from each year.

My Science Club is made of 13 students from years 2 to 6 (so ages 7 to 11). I’m running several experiments with them throughout the year. One of them is actually Eratosthenes’ method of measuring the size of the Earth, modified slightly. I’m getting the kids to measure the length of a vertical stick’s shadow every day at noon. At the end of the year I’ll help them plot the length versus day of the year, and we’ll fit a sine curve and extract the parameters to let us calculate the size of the Earth.

This Monday, I have another Science Club meeting, and I’ve been preparing a different experiment, on colour perception and naming. This is a cool topic that I’ve been interested in ever since I attended an imaging conference and saw some talks about the psychophysics and cultural psychology of colour perception. What I’ve done is to visit a local hardware store and raid their set of house paint sample brochures. Then I cut them up:

Cutting up paint brochures

I had way too many colours, many of which were very similar to others, so I selected a representative subset to try and span as much of the colour space as I could. Then I arranged them and used double sided tape to stick them into manila folders:

Sticking samples into folders

A couple of hours later, and I had 13 folders with identically laid out colour swatches inside:

Colour swatch folders

I used a marker to label all the swatches in each folder with a number. There are 35 swatches:

The 35 colour swatches

Now, here’s the experiment: On Monday in Science Club I’ll give each of the students one of the folders. I’ll also give them a potential list of colour names, with over 100 possible colour names on it:

List of colour names

Their task is to look at each colour, decide which name is the best name for it, and write the colour number on the sheet next to that name. Repeat for all 35 colours. So a lot of the names are going to be left unused. And I’ve included a few write-in slots for any cases where a student is positive that a certain colour really must be called “nasty bruise” or whatever. I’ve been careful to pick names that young children can relate to, and avoid weird things like “heliotrope” and “malachite” that they’ve probably never heard.

The science behind this experiment is that we’re all pretty good and consistent at naming very basic colours like red, and yellow, and blue, but when it comes to naming more subtle shades we are actually highly inconsistent. Is that particular shade of red: rose red, or raspberry, or cherry, or something else? Ask a lot of people and you’ll get a lot of different answers. There are classic studies showing this. (And yes, Randall Munroe of xkcd did a similar thing online a while back and published the results.)

There’s also a study showing that people are inconsistent with themselves, if given exactly the same task a few weeks later. Nearly everyone changes their mind on what certain shades should be called. So this is my experiment with my Science Club! I’m not going to tell the kids that we’ll be repeating this task later in the year. It’ll be interesting to see how closely they can reproduce their own results then, and also how closely their answers align with one another.

Basically, I’m doing something that happens with all good science. I’m replicating an experiment to see if I can reproduce the results. And now that I have this experiment ready to go, I’ll get on to writing up another proof that the Earth is a globe… hopefully within the next few days.