Tag Archives: statistics

Falsehood: Correlation Implies/Does Not Imply Causality

As is the case with any good falsehoods, one can never really be sure what the falsehood may actually be. In this case, there are two falsehoods: 1) When we see a statistical correlation between two measurements or observations, we can not assume that there is a causal link from one to the other. This is the way the statement “Correlation does not imply causality” or some similar version of that aphorism generally means, and this is an admonishment we often hear; and 2) When we see a statistical correlation between two measurements or observations, there probably is a causal link in there somewhere, even when we hear the admonishment “Correlation does not imply causality” from someone, usually on the Internet. To put a finer point on this: What do you think people mean when they say “Correlation does not equal causality?” or, perhaps more importantly, what do you think that statement invokes in other people’s minds?
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How to do Statistics Wrong

Telling people that they are doing statistics wrong is a cottage industry that I usually want nothing to do with, for various reasons including the fact that the naysayers are often blindly repeating stuff they heard but do not understand. But, Alex Reinhart, in Statistics Done Wrong: The Woefully Complete Guide, does not do that, and this is a book that is worth reading for anyone who either generates or needs to interpret statistics.

Most of the 10 chapters that address specific technical problems with statistics, where they are misused or misinterpreted, are very helpful in guiding a reader in how to think about statistics, and certain fallacies or common errors may well apply to a particular person’s work on a regular basis. I’ve put the table of contents below so you can see how this may apply to you. This is a worthy addition to the bookshelf. Get this book and stop doing your stats wrong!

The author is a grad student and physical scientist at Carnegie Mellon.

Here’s the table of contents:

Chapter 1: An Introduction to Statistical Significance
Chapter 2: Statistical Power and Underpowered Statistics
Chapter 3: Pseudoreplication: Choose Your Data Wisely
Chapter 4: The p Value and the Base Rate Fallacy
Chapter 5: Bad Judges of Significance
Chapter 6: Double-Dipping in the Data
Chapter 7: Continuity Errors
Chapter 8: Model Abuse
Chapter 9: Researcher Freedom:Good Vibrations?
Chapter 10: Everybody Makes Mistakes
Chapter 11: Hiding the Data
Chapter 12: What Can Be Done?

The Manga Guide to Regression Analysis

Manga is the Japanese sounding but not used so much in Japan term for a form of cartooning art that has its roots from before World War II but that emerged in its common form during the post war Occupation period. Early used in political cartooning, Manga style drawing is now used for a wide range of expression, and has a place in illustrating a wide range of products, read by Japanese citizens of all sorts and ages. Outside of Japan, Manga is the starting point for the wildly popular Anime style of expression, which of course brings us to…

Pokeman go

But, we are not here to talk about Pokeman go. We are here to talk about Regression Analysis.

No Starch Press has been producing Manga Guides for some years now. They cover many area of math, science, and technology. (I’ve provided a list below.)

The most recent Manga Guide is The Manga Guide to Regression Analysis by Shin Takahashi and Iroha Inoue.

This book presents the story if Miu, a young woman who is having some trouble understanding regression analysis. But she has a love interest to inspire her, and a brilliant coworker to guide her, and with these motivations and tools embarks on a learning journey to grasp such concepts as how to calculate the regression equation and check it’s accuracy, how to use correlation coefficients, test hypotheses, conduct analyses of variance (and analysis of variance is mathematically identical to a regression analysis), predict odds ratios, and do a few parametric statistics to boot.

This is the book that a graduate student who needs to know regression, but is not in a highly mathematical field and skipped college Statistics, will read, learn from, and later claim belongs to his younger brother. Or, that a science-oriented non scientist who is tired of glossing over the statistical parts of the science she reads can use to get up to speed. Or, that a business person or political junkie who wants to use basic regression tools to spot trends or predict primary outcomes might find helpful.

I think that Manga is a medium that many people relate to and find comfortable, and for such individuals, all of the Manga guides, to various math and science concepts, are great. If you have a high school student in your life who is facing a stats course, this is a good gift. Even though the book focuses on Regression, you should know that regression analysis incorporates, or in some way relates to, the vast majority of statistical techniques. When I’ve taught or tutored graduate level stats, and I learned this from the famous Mark Pagel, I’ve always focused on regression because it is very intuitive, yet powerful, and touches on everything. In other words, if you are going to learn one advanced statistical technique, make it (multiple variable) regression.

Interestingly, The Manga Guide to Regression Analysis is a great introduction, but it is not confined to basic regression. The material in this book takes you through a number of different ways to do regression, and will bring you to the point where you should be able to understand and swap in any of the numerious alternative modeling approaches that are out there and available in various statistical packages.

An appendix provides a guide to using Excel to do regression analysis.

Other Manga Guides

<li><a  href="https://www.amazon.com/gp/product/1593274408/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593274408&linkCode=as2&tag=grlasbl0a-20&linkId=8f4446517c41182a25c30bd7d6bddb42">The Manga Guide to Physiology</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593274408" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593271964/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593271964&linkCode=as2&tag=grlasbl0a-20&linkId=be50acdd1e7c35d849b4be4ef737e580">The Manga Guide to Physics</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593271964" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593271972/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593271972&linkCode=as2&tag=grlasbl0a-20&linkId=28ebb6187119eafa087f3e9b6ce7b5d7">The Manga Guide to Electricity</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593271972" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593274130/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593274130&linkCode=as2&tag=grlasbl0a-20&linkId=f2cf04b8bb7fdfbd96d8e432f21b8cb5">The Manga Guide to Linear Algebra</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593274130" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593271891/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593271891&linkCode=as2&tag=grlasbl0a-20&linkId=d9d8af91ed673f2635593459bd119c8f">The Manga Guide to Statistics</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593271891" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593272766/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593272766&linkCode=as2&tag=grlasbl0a-20&linkId=79434e52a8a220d5f62b3fd5550290e3">The Manga Guide to Biochemistry</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593272766" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593271948/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593271948&linkCode=as2&tag=grlasbl0a-20&linkId=afadb72bd949b447e7236436eafdaa32">The Manga Guide to Calculus</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593271948" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

<li><a  href="https://www.amazon.com/gp/product/1593271905/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=1593271905&linkCode=as2&tag=grlasbl0a-20&linkId=a34cafdd58d40c57ec354e4493808d42">The Manga Guide to Databases</a><img src="//ir-na.amazon-adsystem.com/e/ir?t=grlasbl0a-20&l=am2&o=1&a=1593271905" width="1" height="1" border="0" alt="" style="border:none !important; margin:0px !important;" /></li>

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William M. Briggs has misunderstood a high-school level data graph

And I suspect he’s done so willingly. Well, you know what they say about statistics and liars.

Here’s the story. The Wall Street Journal and the Daily Mail independently published highly misleading and blatantly idiotic pieces on climate change. We’ve covered this extensively already over the last few days. Phil Plait, of the Bad Astronomy Blog on Discovermagazine.com, was one of numerous scientists to respond to those flaming examples of horrific bottom feeding journalism with the post “While temperatures rise, denialists reach lower.” In that post, he presented a still-image from a moving GIF that has been going around, originally from Skeptical Science. I’ve used the GIF myself just recently, but I’ll re-post it here for your convenience:

Continue reading William M. Briggs has misunderstood a high-school level data graph