Things 109: Jonathan’s Card, Dr Who Cats, Mix Shift Visualisation

Question – Nothing to Hide
As technology makes surveillance of many kinds ever easier, some people  are worried about Big Brother, two words which conveniently encompass the general idea that this would be bad, via Orwell’s 1984, which incidentally is one of those classics that you really should read if you haven’t yet as it is only becoming more relevant.

In response to this, others say “If you have nothing to hide, then you have nothing to fear,” which is powerfully concise rebuttal to these vague fears.

I can think of some counterarguments to that, but they tend to be long, and as noted by The Brads, something that takes more than 140 characters to explain doesn’t generally spread. So: this week’s challenge is to come up with a counterargument for “nothing to hide” that is 140 characters long or fewer.

A while ago, as an experiment, Jonathan Stark made his Starbucks card details public, so anyone could add credit and anyone could spend that credit. His page explaining this is here. (Note the caveat at the top – this no longer works).

Sam Odio found an easy way to transfer credit to his own Starbucks card, and I recommend reading his take on the idea (and his exploit) here.

If you don’t have time for that, you could just read this summary of the whole story over at Good, which lays out the whole strange tale.

Les Dawson:

“There is a remote tribe that worships the number zero. Is nothing sacred?”

Picture (via Jason)
Pure internet linkbait, but with an execution this good, it deserves to be: Dr Who cats.

Previous Puzzle
Last time I asked for ways to visualise data in such a way that mix shifts affecting conversion rate would be readily apparent.

Adam naturally had a full consultant’s answer, explaining how he would show the data different ways depending on the audience (sales director, website content manager, SEO manager…), and how he might talk through the component parts of the change in a sequence of slides, which is all very sensible. However, what I really want is something that I as an analyst can look at to apprehend the whole situation, ideally in a generic way, so any given shift becomes clear.

Simon described an interesting single-view answer, but in preparing this post I realised I needed to confirm some of its details with him, so that will have to wait for a later edition of Things.

On to my answer… the data set was as follows:

[before mix shift | after mix shift]:

Banjo section visits [10,000 | 20,000] – lots more traffic
Banjo section sales [100 | 220]
Banjo section conversion [1.0% | 1.1%] – conversion increases!

Gun section visits [1,000 | 1,000] – same traffic as ever
Gun section sales [100 | 110]
Gun section conversion [10% | 11%] – conversion increases!

Overall conversion before:
(100 + 100) / (10,000 + 1,000) = 1.82%
Overall conversion after:
(220 + 110) / (20,000 + 1,000) = 1.57% – overall conversion has decreased!

My solution looks like this:

This shows how the total visits and orders (black lines) are composed of the individual sections (red/gun and blue/banjo). While both the blue and red arrows get steeper (representing improved conversion, although it’s hard to see this on the red arrow), the angle of the black line decreases (representing the overall decrease in conversion), since the blue arrow became so much longer.

This pretty much works for the extreme example given. However, it has significant weaknesses as a general solution:

  • It doesn’t work as a trended view – conceivably it could be animated, but that seems like overkill
  • It’s hard to compare the angle of arrows when traffic changes significantly, as in the gun section above
  • It tends to encode all the interesting information into a narrow diagonal band of the chart.

Further improvements are of course welcome!

-Transmission Ends


Things 74: Swing, Freezer Door, Carnist Bingo

A test audience on Facebook didn’t find this remotely as incredible as I did, but here it is anyway: The Swinger, an algorithmic process that can automatically generate a swing remix of a song.I recommend trying out whichever of the songs listed you are most familiar with, but for me “Money For Nothing” had the most profound effect.

Marie, during an argument: “Ah, but I’m a philosopher; numbers don’t exist.”

Anyone that has watched enough movies or TV is familiar with the dangers of an industrial freezer room: if you happen to get shut inside, you are doomed, since the door can only be opened from outside. But this seems like a very strange design flaw. Why are those doors designed in such a way?

As a vegetarian, I’ve found myself in many minor debates on food ethics over the years. A strange feature of these debates is that meat eaters have not generally applied as much thought to what they personally think they should or should not eat, and as a result vegetarians (and especially vegans) tend to find themselves arguing against the same instinctive, poorly-thought-out arguments every time. The Secret Society of Vegans found an excellent answer to this recurring feature of any v*gan’s life: a ‘bingo’ card for use during such debates:

Last Week’s Puzzle
Last week I asked how turning over a cassette caused the other side of the tape to be read. In fact the ‘side’ terminology only applies to the cassette – the tape itself has one ‘side’ of music recorded in one direction along the top, and the other in the opposite direction along the bottom.

Tarim points out that 8-track tape is much more mind-boggling: the tape is a continuous loop, wrapped around a single spool, with one end necessarily being pulled out from the inner part of the spiral. How could such a mechanism overcome so much friction in order to run continuously?