The Dunning-Kruger Effect

Posted on November 17, 2015November 17, 2015 by McCoy

The Strange Case of a Non-Invisible Man

There's a poker saying I've always been fond of: “If you sit in on a poker game and don't see a sucker, get up. You're the sucker.”

It's a great rule to live by, and not just in poker, but it’s pretty distressing how many people have obviously never heard it. We've all met them: people who completely fail to recognize their own incompetence, or think that they are geniuses despite overwhelming evidence to the contrary.

There's actually a name for this: The Dunning-Kruger effect. Though it was hardly a stunning revelation to anyone, David Dunning and Justin Kruger were the first ones to actually test for the phenomena. They were inspired by a news story about a man named McArthur Wheeler, who robbed a pair of banks after smearing lemon juice on his face. Apparently, he thought that lemon juice would make his face invisible to cameras, since lemon juice is usable as invisible ink.

During their testing, Dunning and Kruger confirmed that unskilled people frequently overestimated their competence. One of the experiments performed involved giving various tests to subjects and then showing the subjects their scores. They then asked the subjects to estimate their rank. Those subjects who tested poorly consistently ranked themselves as much as 50 percentiles higher than their actual score.

Dunning and Kruger found an interesting flip side to the effect: highly skilled individuals tend to frequently underestimate their own competence—or, rather, they overestimated the competence of others—an effect that seems quite similar to Impostor Syndrome, which occurs when people are unable to really acknowledge their achievements.

I usually don't have a lot of interest in psychology; I tend to read much more about other social sciences, especially history and archeology. Why am I getting into it now?

Easy. I'm willing to put a lot of work into my insults, especially when they involve incompetent coworkers.

Kiva Robots: A Bit Like Forklifts

Posted on September 8, 2015February 23, 2021 by McCoy

The Kiva robots are like big, square Roomba robot vacuum cleaners, though they function more like forklifts. They're about 16 inches tall and weigh 320 pounds When a customer orders something on Amazon, a robot is dispatched with orders to retrieve the tall, thin square shelf that the item is on.

The Kivas roll through the Amazon warehouses, carefully guided and controlled by a central computer to avoid collisions. They scoot under shelves, stopping when they reach the programmed location and spin in place to lift the shelf. Then they pilot the whole shelf to a station where a human employee grabs the customer's order. The order then travels through an array of other steps to get to the customer.

Amazon has more than 15,000 of these robots in their warehouses right now, processing a majority of the orders. Establishing a testing a system for a warehouse can take quite a while, sometimes months. Amazon's engineers have to assure that the army of robots on the warehouse floor can move about without running into one another and toppling shelves over left and right, which is no easy task.

They also have to set the system up for prioritizing where to set shelves, in order to minimize retrieval times for the robots.

Surprisingly enough, the Kiva robots haven't resulted in job losses. Instead, the workers move from the picking-and-sorting jobs to train in other positions. In this scenario, when more robots are added, more work is created for the human workers. Seemingly: everybody wins. Plus, as anyone who has ever worked in a warehouse can easily attest, picking is a job tailor-made for robots.

The Stingless Bee

Posted on August 25, 2015August 25, 2015 by McCoy

I'm not especially knowledgeable about farming. Irrigation? That I know a little bit about. Crops and animal husbandry? Much less. Every now and then, I do run across something really interesting. In this case: the Mayan stingless bee.

The stingless bees, also known as meliponines, are frequently kept in homes as pets. The Central American varieties bred by the Maya are kept in hollow logs with ceramic caps at either end that can be removed to gather honey. They are still kept this way today, in the same way they have been for countless centuries. The hives are often passed down between generations, and it’s common for hives to last 80 years.

They have more uses than just as pets or to make honey. They're also used for religious purposes. Beekeepers would place the hives near certain hallucinogenic flowers, so that the honey made from them kept some of those properties, which were then turned into a sort of honey wine used in ritual practices. I reckon that there's a lot less falling asleep in church there.

Metalworkers also frequently kept bees in Central America in order to use their wax for lost-wax casting. Lost wax casting involves the creation of a wax model, followed by the creation of a mould and then a hollow wax model, after which the model is covered in a more durable material and filled with molten metal. (Yep: I've got a slightly shaky grasp on it.)

Central America isn't the only center of stingless bee cultivation. Brazil and Australia are also involved.

Unfortunately, the cultivation of stingless bees in Central America has been dropping away in favor of Africanized bees (sometime called killer bees, which is actually inaccurate; you're more likely to be hit by lightning than killed by Africanized bees), who produce much larger amounts of honey. One of the major downsides of this is that Africanized bees neglect a number of local flowers, which results in many local plants not getting fertilized.

The End of the VHS Loop

Posted on August 19, 2015August 19, 2015 by McCoy

Maggie had me cleaning out the attic the other day, and I found a cardboard box filled with old VHS tapes. We hadn't used the VCR in something like a decade, but I managed to find it (in the garage, under five or six cans of paint) and hooked it up.

I went through some of our old home videos, and found that some worked perfectly fine and others didn't work at all. There didn't seem to be any real link between their age and how well they worked, either, so I decided to do some research.

There are lots of stories bouncing around the internet about how VHS tapes are supposed to stop working after ten years, or 15, or 20, but there doesn't seem to be any real consensus. People have written their anecdotes about all sorts of lifespans for the dumb things.

It turns out that there are a lot of reasons for the wildly different stories. First off, there was a lot of advertising done when DVDs came out—trying to convince people to switch from VHS to DVD, with the claim that VHS tapes wouldn't last very long.

And the conditions that cause the tapes to wear out vary wildly. VCR malfunction is the quickest cause, of course, but other factors include: rapid temperature swings, frequent use, low humidity, proximity to magnets and electronics, and storage conditions.

What makes it even more confusing is that many of the factors aren't even consistent. Infrequent usage can sometimes cause the tapes to fail, and frequent use can do the same thing.

The last movie released on VHS was “A History of Violence,” in 2006. I doubt that a copy of this will be the last movie ever watched in the format, of course: by that time DVDs had pretty much taken over the whole scene, leaving very little of a VHS market remaining. The “last view” honor will most likely go to someone's home movie, and probably within the next 50 years.

Honoring the Hurriquake Nail

Posted on July 21, 2015July 21, 2015 by McCoy

The HurriQuake

Disaster-proofing homes is not something you want to skimp on, especially if you’re living somewhere with tornadoes, earthquakes, hurricanes, or door-to-door encyclopedia salesmen at six in the morning. Generally speaking, building codes require a certain level of disaster-proofing in new buildings, depending on the area. It’s always better to be safe than sorry.

Disaster proofing can, of course, get pretty frivolous. There really isn’t a particularly compelling reason to install blast-proof wallpaper in your average suburban home in America (anyone who lived through part of the Cold War remembers bomb shelter advertisements).

One technical advancement that I do find pretty worthwhile, however, is the HurriQuake nail. (Engineers should never get to name things.) This is a bizarre-looking cross between a nail and a screw, and it’s specifically designed to withstand extreme amounts of stress, from causes ranging from high wind to earthquakes. It actually won Best Innovation of the Year from Popular Science in 2006.

The nail is actually so strong that the boards the HurriQuake nail is hammered/screwed into usually fail before the nail does. And it’s cheap enough that it only drives up the cost of houses by a few dollars.

That’s not to say the HurriQuake nail is perfect. If you put one in the wrong spot, good luck getting it out. The same spikes that keep it lodged in boards—even under extreme force—are largely capable of resisting much more force than you can apply.

isabel Of course, fancy nails alone aren’t enough to disaster-proof a house. You’ve got to design the whole building, foundation to roof, with that goal in mind. It’ll cost more and take more work, too, but this is a key part of designing a house to fit the environment it’s in. Which is one reason you see so many antique houses outlasting suburban cookie-cutter houses.