Linkspam: April 15th, 2017

Yeah, just finished my taxes!  So now it’s time for my monthly linkspam.

Double-Dipping Datasets – Why is it wrong to use an old dataset in order to answer new questions? Answer: It’s not wrong, I do it all the time in my research. Oh, and social scientists do it too, as in the well-known study from 2004 showing that asexuals make up about 1% of the population–based on a survey from 1990.  Nonetheless, there are some cases where it intuitively seems like using the same dataset twice sounds wrong.  HJ Hornbeck digs into some of the reasons why.

Here’s another thought.  Researchers have limited resources and can only collect so much data.  Collecting a few large datasets and using those for many purposes is fine.  But if you’re collecting lots of little sets of data, you shouldn’t be testing lots of hypotheses on each data set until you get a hit.

Trans 101: Put Down the Map – Heh, well this isn’t the kind of article that tries to explain trans issues in a simplified and accessible format.  There’s a lot about epistemology, using the “map vs territory” metaphor.  I will say that every social justice advocate should have a healthy amount of empiricism, and that’s why we encourage listening to people rather than just theorizing about them.

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Paper: Overbooking flights

In recent news (cn: autoplay), a United Airlines passenger was unwillingly dragged off a plane to make seats for employees. The incident was partially blamed on the common practice of airlines to deliberately overbook flights in order to make up for all the no-show passengers.

While I won’t discuss the particulars of this incident, I am willing to do something that most journalists are not: read relevant academic literature. I just picked one paper that appeared to have a sufficiently broad perspective:

Marvin Rothstein, (1985) OR Forum – OR and the Airline Overbooking Problem. Operations Research 33(2):237-248.

The basic problem is that many people who buy airplane tickets don’t show up. In 1961, the Civil Aeronautics Board (CAB) reported that 1 out of 11 ticket sales were no-shows. These numbers are about the same today, with 7-8% no-shows. The airlines could create wait lists to fill the empty seats, but it would be impossible to contact the wait-listed customers in a timely fashion unless they were already present at the gate.

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Immigration is a science issue

The March for Science happens this next Saturday. I don’t typically participate in protests, but if you’re interested there are hundreds of them occurring throughout the world. The March for Science website explains why they organize:

Science, scientists, and evidence-based policymaking are under attack. Budget cuts, censorship of researchers, disappearing datasets, and threats to dismantle government agencies harm us all, putting our health, food, air, water, climate, and jobs at risk. It is time for people who support science to take a public stand and be counted.

I’m surprised by an omission from this agenda: immigration policy. Immigration is very obviously a science issue. My advisor is an immigrant. 1/3 to 1/2 of the students and postdocs in my research group have been immigrants. The same is true of my class. The effect is so large, you hardly need statistics to show it.

Nonetheless, some statistics…

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Cards Against Humanity is a bad game

Cards Against Humanity is first and foremost a ripoff of Apples to Apples. The rules are identical, only the cards are different. There’s no copyright on game mechanics, you see.

Apples to Apples is a family-friendly party game, published in 1999. It had a lot of staying power; I recall playing it in college about ten years later. My boyfriend and I have an old copy on our shelf, which proudly states, “Over three million games sold!” Going by their website, that number is now 15 million.

Cards Against Humanity was published in 2011. I don’t know how many copies it has sold, but it obviously became a bigger deal than Apples to Apples.

To be honest, I was never hot on Apples to Apples. It’s the lightest of light party games, a great board game for people who don’t really like board games. Nonetheless, I appreciate it’s clever design, and I’ll talk about how Cards Against Humanity used and abused that design.

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Dolezal

Rachel Dolezal came to national attention in 2015 when people discovered that she was a White person living and identifying as a Black person. You can read more details in a recent New York Times article and interview.

I would question the standard liberal reaction to Rachel Dolezal–that is, that she’s a waste of space, mentally ill, and worthy of hatred. I am not playing devil’s advocate. Dolezal’s story has been of personal interest to me since I saw it in 2015, because I immediately recognized some of myself in it.

There were obviously many relevant differences between us, and many critiques of Dolezal seem justified. But it bothered me to see her receive so much hatred. Two years later, I’ve now had more time to think about it and sort out the issues.

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Origami: The failure files

Sometimes an origami model just doesn’t work out.  Here’s a collection of some of my failures.

failed flexible polyhedron
One thing I’m interested in doing is finding unusual polyhedra, and designing origami around them.  This here was meant to be Steffen’s polyhedron, which is a flexible and concave polyhedron.  “Flexible” means that it can be deformed even when each of the faces is rigid.  “Concave” means that some of its edges are bent inwards instead of outwards.  Cauchy’s Rigidity theorem states that convex polyhedra cannot be flexible, and Steffen’s polyhedron is an example of why it doesn’t also apply to concave polyhedra.

Anyway, this is tricky to design because I basically need to make a bunch of triangles of arbitrary sizes, and I need some way to attach them together.  At some point, I got the bright idea of making triangle edges rather than triangles.  And I didn’t even have to design my own edges, I just took the “Jade” units from Ekaterina Lukasheva, which are designed to be of arbitrary length.  I carefully cut the paper to size (which required a bunch of oddly dimensioned rectangles, like 10:17), and started putting pieces together.

But it turns out, the design was fundamentally flawed.  The geometry of the jade units doesn’t work out, and you just can’t put arbitrary triangles together with it.  Well, back to the drawing board.

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Clearer thinking about definitions

Do you believe that people waste too much time arguing over definitions?

I do too. But I also have a second problem: I’ve read some philosophy. And so, when I’m frustrated with pointless arguments over definitions, my frustration becomes compounded by the fact that nobody understands the thing that they’re arguing about, and the only way to solve the problem is by spending even more time arguing over useless stuff.

Case in point, in all the time you’ve ever spent arguing over definitions, have you ever once glanced at the relevant articles in either Wikipedia or the Stanford Encyclopedia of Philosophy? I’m guessing not, because I never thought to do such a thing myself for a long time.

So now that I’ve made everyone feel guilty, let’s talk about one of the things you’d learn from some basic research: intensional vs extensional definitions.

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