Posts Tagged ‘ Miscellaneous Statistics ’

Solution to the helicopter design problem

October 24, 2014
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See yesterday’s post for background. Here’s the question: In the helicopter activity, pairs of students design paper ”helicopters” and compete to create the copter that takes longest to reach the ground when dropped from a fixed height. The two parameters of the helicopter, a and b, correspond to the length of certain cuts in the […] The post Solution to the helicopter design problem appeared first on Statistical Modeling, Causal…

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Some questions from our Ph.D. statistics qualifying exam

October 23, 2014
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In the in-class applied statistics qualifying exam, students had 4 hours to do 6 problems. Here were the 3 problems I submitted: In the helicopter activity, pairs of students design paper ”helicopters” and compete to create the copter that takes longest to reach the ground when dropped from a fixed height. The two parameters of the […] The post Some questions from our Ph.D. statistics qualifying exam appeared first on Statistical…

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Hoe noem je?

October 18, 2014
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Haynes Goddard writes: Reviewing my notes and books on categorical data analysis, the term “nominal” is widely employed to refer to variables without any natural ordering. I was a language major in UG school and knew that the etymology of nominal is the Latin word nomen (from the Online Etymological Dictionary: early 15c., “pertaining to […] The post Hoe noem je? appeared first on Statistical Modeling, Causal Inference, and Social…

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The Fault in Our Stars: It’s even worse than they say

October 15, 2014
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The Fault in Our Stars:  It’s even worse than they say

In our recent discussion of publication bias, a commenter link to a recent paper, “Star Wars: The Empirics Strike Back,” by Abel Brodeur, Mathias Le, Marc Sangnier, Yanos Zylberberg, who point to the notorious overrepresentation in scientific publications of p-values that are just below 0.05 (that is, just barely statistically significant at the conventional level) […] The post The Fault in Our Stars: It’s even worse than they say appeared…

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I didn’t say that! Part 2

October 14, 2014
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Uh oh, this is getting kinda embarrassing. The Garden of Forking Paths paper, by Eric Loken and myself, just appeared in American Scientist. Here’s our manuscript version (“The garden of forking paths: Why multiple comparisons can be a problem, even when there is no ‘fishing expedition’ or ‘p-hacking’ and the research hypothesis was posited ahead […] The post I didn’t say that! Part 2 appeared first on Statistical Modeling, Causal…

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When there’s a lot of variation, it can be a mistake to make statements about “typical” attitudes

October 8, 2014
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When there’s a lot of variation, it can be a mistake to make statements about “typical” attitudes

This story has two points: 1. There’s a tendency for scientific results to be framed in absolute terms (in psychology, this corresponds to general claims about the population) but that can be a mistake in that sometimes the most important part of the story is variation; and 2. Before getting to the comparisons, it can […]

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“We have used Stan to study dead dolphins”

October 6, 2014
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“We have used Stan to study dead dolphins”

In response to our call for references to successful research using Stan, Matthieu Authier points us to this: @article{ year={2014}, journal={Biodiversity and Conservation}, volume={23}, number={10}, doi={10.1007/s10531-014-0741-3}, title={How much are stranding records affected by variation in reporting rates? A case study of small delphinids in the Bay of Biscay}, url={http://dx.doi.org/10.1007/s10531-014-0741-3}, keywords={Monitoring; Marine mammal; Strandings}, author={Authier, Matthieu […]

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Anova is great—if you interpret it as a way of structuring a model, not if you focus on F tests

October 5, 2014
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Shravan Vasishth writes: I saw on your blog post that you listed aggregation as one of the desirable things to do. Do you agree with the following argument? I want to point out a problem with repeated measures ANOVA in talk: In a planned experiment, say a 2×2 design, when we do a repeated measures […]

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Waic for time series

September 25, 2014
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Helen Steingroever writes: I’m currently working on a model comparison paper using WAIC, and would like to ask you the following question about the WAIC computation: I have data of one participant that consist of 100 sequential choices (you can think of these data as being a time series). I want to compute the WAIC […]

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Six quotes from Kaiser Fung

September 14, 2014
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You may think you have all of the data. You don’t. One of the biggest myth of Big Data is that data alone produce complete answers. Their “data” have done no arguing; it is the humans who are making this claim. Before getting into the methodological issues, one needs to ask the most basic question. […]

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