TEST YOUR ESTIMATION SKILLS Click to enlarge Suppose you are looking at the roughly normally distributed data above and you want to visually estimate the standard deviation. What would you guess? 20? 35? How would you do it? In a past post we talked about tips for drawing a normal distribution. In it, we noted […]
KNOW THY INFLECTION POINT Click to Enlarge We have drawn a lot of sorry-looking normal distributions in our life. It’s a shape that’s hard to get down without a lot of practice. Here’s a few tips that can make it easier. Start by marking out standard deviations on the x axis from -3 to +3 […]
WIND SPEEDS UP HEAT LOSS Twenty years ago, a German colleague asked me what the deal was with wind chill. I guess they didn’t have it in Germany. I explained it was an attempt to communicate how it feels when there is a low temperature combined with wind. But my colleague wanted to know how […]
PERCEIVED TEMPERATURE Click to enlarge (We got a request for a Celsius version of this post and since we are a full service website we created one and put it here). So, we were wondering, what’s this heat index we hear about? We went to the Wikipedia article on it. It is an index that […]
BAGEL SHOP IDEA I was sitting in a bagel shop on Saturday with my 9 year old daughter. We had brought along hexagonal graph paper and a six sided die. We decided that we would choose a hexagon in the middle of the page and then roll the die to determine a direction: 1 up […]
STREAK RESULTS FOR LIKELY (>50%) and HIGHLY LIKELY (>99%) Click to enlarge From research on the hot hand to the observation that people don’t create enough streaks when instructed to create pseudo random data, the decision science community is pretty interested in the perception of streaks. One day we got to wonder, how long would […]
PUTTING 35 INCHES OF RAIN IN PERSPECTIVE We are always interested in putting numbers into perspective, so we were interested in this article in which they put the Hurricane Harvey’s rain into perspective. They’re predicting 30-40 inches of rain in a few days in Texas. They asked an expert to put that into perspective and […]
K-MEANS CLUSTERING, A WORKHORSE OF DATA SCIENCE AND MACHINE LEARNING CLICK TO ENLARGE The USA is a large country. How different are people’s experiences of the weather depending on where they live? To look into this question, we downloaded high temperature data for over 1,300 airport weather stations in the contiguous USA for every day […]
DENSITY THE AVERAGE PERSON EXPERIENCES CLICK TO ENLARGE In Alaska, there’s about one person for each square mile of land. You might picture a typical Alaskan not being able to see the next house. But it’s not that way of course. Most of Alaska is uninhabited. People have crowded into a few areas. The average […]
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