Posts Tagged ‘ science ’

Cluster analysis in the classroom

March 4, 2015
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Cluster analysis in the classroom

I am a guest at the New School's Journalism + Design program this semester. The students conducted interviews about the question of what makes someone famous. Their interviewees were asked to name five famous people. We had images of these people up on the wall. Then, we put the pictures into clusters. We tried two different ways of doing it. At the end, we compared our result to what a…

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What have a physicist, an entrepreneur and an actor in common?

February 10, 2015
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What have a physicist, an entrepreneur and an actor in common?

They all try to do something new and take the risk to be seen as a fool.Over the last few days I stumbled over three videos by a physicist, an entrepreneur and an actor, which at first have little in common, but they do. They all need to know when they...

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Deflate-gate, Part 2: not average != extreme, and Sunday talk shows

February 2, 2015
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Last week, I pointed out the futility of using data as proof or disproof in Deflate-gate. Emphatically, a case of "N=All" does not make things better. I later edited the post for HBR (link). In this post, I want to address a couple of more subtle technical issues related to the Sharp analysis, which can be summarized as follows: 1. New England is an outlier in the plays per fumbles…

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Football and statistics, on HBR!

January 30, 2015
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I was asked to adapt my earlier post for the HBR audience, and the new version is now up on HBR. Here is the link. I'm happy that they picked up this post because most business problems concern reverse causation. A small subset of problems can be solved using A/B testing, but only those in which causes are known in advance and subject to manipulation. Even then, Facebook got into…

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Limits of statistics, and by extension data science, as illustrated by Deflate-gate

January 27, 2015
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Limits of statistics, and by extension data science, as illustrated by Deflate-gate

A number of readers sent me Warren Sharp's piece about the ongoing New England Patriots' deflate-gate scandal (link to Slate's version of this) so I suppose I should say something about it. For those readers who are not into American football, the Superbowl is soon upon us. New England, one of the two finalists, has been accused of using footballs that are below the weight requirements on the rulebook, hence…

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How Optimizely will kill your winning percentage, and why that is a great thing for you (Part 1)

January 23, 2015
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In my HBR article about A/B testing (link), I described one of the key managerial problems related to A/B testing--the surplus of “positive” results that don’t quite seem to add up. In particular, I mentioned this issue: When managers are reading hour-by-hour results, they will sometimes find large gaps between Groups A and B, and demand prompt reaction. Almost all such fluctuations result from temporary imbalance between the two groups,…

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Three reasons to doubt the GDP-gas price conjecture

January 20, 2015
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Dragged by infectious incuriosity, the financial press ran with the story that falling gasoline prices (50% drop in 6 months) is "the best economic stimulus one can get". See former Deputy Treasury Secretary Robert Altman on CNBC, Business Insider's "cheap gas boost", Wall Street Journal citing the "low oil prices as an effective tax cut for consumers", New York Times quoting a Citigroup analyst claiming a global > $1 trillion…

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Trifacta revisited: tackling a Big Data problem

January 12, 2015
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During my vacation, I had a chance to visit Trifacta, the data-wrangling startup I blogged about last year (link). Wei Zheng, Tye Rattenbury, and Will Davis hosted me, and showed some of the new stuff they are working on. Trifacta is tackling a major Big Data problem, and I remain excited about the direction they are heading. From the beginning, I am attracted by Trifacta’s user interface. The user in…

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A great start to the year

January 1, 2015
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A great start to the year

I'd like to start 2015 on a happy note. I enjoyed reading the piece by Steven Rattner in the New York Times called "The Year in Charts". (link) I particularly like the crisp headers, and unfussy language, placing the charts...

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Proxy unmasking

December 25, 2014
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Consider this paragraph from a FiveThirtyEight article about the small-schools movement (my italics): Hanushek calculated the economic value of good and bad teachers, combining the “quality” of a teacher — based on student achievement on tests — with the lifetime earnings of an average American entering the workforce. He found that a very high-performing teacher with a class of 20 students could raise her pupils’ average lifetime earnings by as…

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