Thursday, February 23, 2017
Global warming: thoughtful observations on reporting
Richard Muller, Prof. Physics UC Berkeley, author "Physics for Future Presidents"
What are some widely cited studies in the news that are false?
Whenever I see the latest headline grabber article citing a certain study as evidence that doing something will cause you to be more rich or have a higher risk of cancer, I am always skeptical if they've really taken the steps to find a cause and effect, or if they are only looking for correlation. I'm looking of good examples of studies that people still talk about that have been clearly disproven and how.
That 97% of all climate scientists accept that climate change is real, large, and a threat to the future of humanity. That 97% basically concur with the vast majority of claims made by Vice President Al Gore in his Nobel Peace Prize winning film, An Inconvenient Truth.
The question asked in typical surveys is neither of those. It is this: “Do you believe that humans are affecting climate?” My answer would be yes. Humans are responsible for about a 1 degree C rise in the average temperature in the last 100 years. So I would be included as one of the 97% who believe.
Yet the observed changes that are scientifically established, in my vast survey of the science, are confined to temperature rise and the resulting small (4-inch) rise in sea level. (The huge “sea level rise” seen in Florida is actually subsidence of the land mass, and is not related to global warming.) There is no significant change in the rate of storms, or of violent storms, including hurricanes and volcanoes. The temperature variability is not increasing. There is no scientifically significant increase in floods or droughts. Even the widely reported warming of Alaska (“the canary in the mine”) doesn’t match the pattern of carbon dioxide increase; and it may have an explanation in terms of changes in the northern Pacific and Atlantic currents. Moreover, the standard climate models have done a very poor job of predicting the temperature rise in Antarctica, so we must be cautious about the danger of confirmation bias.
My friend Will Happer believes that humans do affect the climate, particularly in cities where concrete and energy use cause what is called the “urban heat island effect”. So he would be included in the 97% who believe that humans affect climate, even though he is usually included among the more intense skeptics of the IPCC. He also feels that humans cause a small amount of global warming (he isn’t convinced it is as large as 1 degree), but he does not think it is heading towards a disaster; he has concluded that the increase in carbon dioxide is good for food production, and has helped mitigate global hunger. Yet he would be included in the 97%.
The problem is not with the survey, which asked a very general question. The problem is that many writers (and scientists!) look at that number and mischaracterize it. The 97% number is typically interpreted to mean that 97% accept the conclusions presented in An Inconvenient Truth by former Vice President Al Gore. That’s certainly not true; even many scientists who are deeply concerned by the small global warming (such as me) reject over 70% of the claims made by Mr. Gore in that movie (as did a judge in the UK; see the following link: Gore climate film's nine 'errors').
The pollsters aren’t to blame. Well, some of them are; they too can do a good poll and then misrepresent what it means. The real problem is that many people who fear global warming (include me) feel that it is necessary to exaggerate the meaning of the polls in order to get action from the public (don’t include me).
There is another way to misrepresent the results of the polls. Yes, 97% of those polled believe that there is human caused climate change. How did they reach that decision? Was it based on a careful reading of the IPCC report? Was it based on their knowledge of the potential systematic uncertainties inherent in the data? Or was it based on their fear that opponents to action are anti-science, so we scientists have to get together and support each other. There is a real danger in people with Ph.D.s joining a consensus that they haven’t vetted professionally.
I like to ask scientists who “believe” in global warming what they think of the data. Do they believe hurricanes are increasing? Almost never do I get the answer “Yes, I looked at that, and they are.” Of course they don’t say that, because if they did I would show them the actual data! Do they say, “I’ve looked at the temperature record, and I agree that the variability is going up”? No. Sometimes they will say, “There was a paper by Jim Hansen that showed the variability was increasing.” To which I reply, “I’ve written to Jim Hansen about that paper, and he agrees with me that it shows no such thing. He even expressed surprise that his paper has been so misinterpreted.”
A really good question would be: “Have you studied climate change enough that you would put your scientific credentials on the line that most of what is said in An Inconvenient Truth is based on accurate scientific results?” My guess is that a large majority of the climate scientists would answer no to that question, and the true percentage of scientists who support the statement I made in the opening paragraph of this comment, that true percentage would be under 30%. That is an unscientific guestimate, based on my experience in asking many scientists about the claims of Al Gore.
Gone: Kahaneman on priming
Reconstruction of a Train Wreck: How Priming Research Went off the Rails
February 2, 2017Kahneman, Priming, r-index, Statistical Power, Thinking Fast and Slow
Authors: Ulrich Schimmack, Moritz Heene, and Kamini Kesavan
Abstract:
We computed the R-Index for studies cited in Chapter 4 of Kahneman’s book “Thinking Fast and Slow.” This chapter focuses on priming studies, starting with John Bargh’s study that led to Kahneman’s open email. The results are eye-opening and jaw-dropping. The chapter cites 12 articles and 11 of the 12 articles have an R-Index below 50. The combined analysis of 31 studies reported in the 12 articles shows 100% significant results with average (median) observed power of 57% and an inflation rate of 43%. The R-Index is 14. This result confirms Kahneman’s prediction that priming research is a train wreck and readers of his book “Thinking Fast and Slow” should not consider the presented studies as scientific evidence that subtle cues in their environment can have strong effects on their behavior outside their awareness.
Introduction
In 2011, Nobel Laureate Daniel Kahneman published a popular book, “Thinking Fast and Slow”, about important finding in social psychology.
In the same year, questions about the trustworthiness of social psychology were raised. A Dutch social psychologist had fabricated data. Eventually over 50 of his articles would be retracted. Another social psychologist published results that appeared to demonstrate the ability to foresee random future events (Bem, 2011). Few researchers believed these results and statistical analysis suggested that the results were not trustworthy (Francis, 2012; Schimmack, 2012). Psychologists started to openly question the credibility of published results.
In the beginning of 2012, Doyen and colleagues published a failure to replicate a prominent study by John Bargh that was featured in Daniel Kahneman’s book. A few month later, Daniel Kahneman distanced himself from Bargh’s research in an open email addressed to John Bargh (Young, 2012):
“As all of you know, of course, questions have been raised about the robustness of priming results…. your field is now the poster child for doubts about the integrity of psychological research… people have now attached a question mark to the field, and it is your responsibility to remove it… all I have personally at stake is that I recently wrote a book that emphasizes priming research as a new approach to the study of associative memory…Count me as a general believer… My reason for writing this letter is that I see a train wreck looming.”
Five years later, Kahneman’s concerns have been largely confirmed. Major studies in social priming research have failed to replicate and the replicability of results in social psychology is estimated to be only 25% (OSC, 2015).
Looking back, it is difficult to understand the uncritical acceptance of social priming as a fact. In “Thinking Fast and Slow” Kahneman wrote “disbelief is not an option. The results are not made up, nor are they statistical flukes. You have no choice but to accept that the major conclusions of these studies are true.”
Yet, Kahneman could have seen the train wreck coming. In 1971, he co-authored an article about scientists’ “exaggerated confidence in the validity of conclusions based on small samples” (Tversky & Kahneman, 1971, p. 105). Yet, many of the studies described in Kahneman’s book had small samples. For example, Bargh’s priming study used only 30 undergraduate students to demonstrate the effect.
From Daniel Kahneman
I accept the basic conclusions of this blog. To be clear, I do so (1) without expressing an opinion about the statistical techniques it employed and (2) without stating an opinion about the validity and replicability of the individual studies I cited.
What the blog gets absolutely right is that I placed too much faith in underpowered studies. As pointed out in the blog, and earlier by Andrew Gelman, there is a special irony in my mistake because the first paper that Amos Tversky and I published was about the belief in the “law of small numbers,” which allows researchers to trust the results of underpowered studies with unreasonably small samples. We also cited Overall (1969) for showing “that the prevalence of studies deficient in statistical power is not only wasteful but actually pernicious: it results in a large proportion of invalid rejections of the null hypothesis among published results.” Our article was written in 1969 and published in 1971, but I failed to internalize its message.
My position when I wrote “Thinking, Fast and Slow” was that if a large body of evidence published in reputable journals supports an initially implausible conclusion, then scientific norms require us to believe that conclusion. Implausibility is not sufficient to justify disbelief, and belief in well-supported scientific conclusions is not optional. This position still seems reasonable to me – it is why I think people should believe in climate change. But the argument only holds when all relevant results are published.
I knew, of course, that the results of priming studies were based on small samples, that the effect sizes were perhaps implausibly large, and that no single study was conclusive on its own. What impressed me was the unanimity and coherence of the results reported by many laboratories. I concluded that priming effects are easy for skilled experimenters to induce, and that they are robust. However, I now understand that my reasoning was flawed and that I should have known better. Unanimity of underpowered studies provides compelling evidence for the existence of a severe file-drawer problem (and/or p-hacking). The argument is inescapable: Studies that are underpowered for the detection of plausible effects must occasionally return non-significant results even when the research hypothesis is true – the absence of these results is evidence that something is amiss in the published record. Furthermore, the existence of a substantial file-drawer effect undermines the two main tools that psychologists use to accumulate evidence for a broad hypotheses: meta-analysis and conceptual replication. Clearly, the experimental evidence for the ideas I presented in that chapter was significantly weaker than I believed when I wrote it. This was simply an error: I knew all I needed to know to moderate my enthusiasm for the surprising and elegant findings that I cited, but I did not think it through. When questions were later raised about the robustness of priming results I hoped that the authors of this research would rally to bolster their case by stronger evidence, but this did not happen.
I still believe that actions can be primed, sometimes even by stimuli of which the person is unaware. There is adequate evidence for all the building blocks: semantic priming, significant processing of stimuli that are not consciously perceived, and ideo-motor activation. I see no reason to draw a sharp line between the priming of thoughts and the priming of actions. A case can therefore be made for priming on this indirect evidence. But I have changed my views about the size of behavioral priming effects – they cannot be as large and as robust as my chapter suggested.
I am still attached to every study that I cited, and have not unbelieved them, to use Daniel Gilbert’s phrase. I would be happy to see each of them replicated in a large sample. The lesson I have learned, however, is that authors who review a field should be wary of using memorable results of underpowered studies as evidence for their claims.
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1. Dr. R
February 14, 2017 at 8:57 pm
Dear Daniel Kahneman,
Thank you for your response to my blog.
Science relies on trust and we all knew that non-significant results were not published, but we had no idea how weak the published results were.
Nobody expected a train-wreck of this magnitude.
Hindsight (like my bias analysis of old studies) is 20/20. The real challenge is how the field and individuals respond to the evidence of a major crisis.
I hope more senior psychologists will follow your example and work towards improving our science.
Although we have fewer answers today than we thought we had five years ago, we still have many important questions that deserve a scientific answer.
Dear Daniel Kahneman, there is another reason to be sceptical of many of the social priming studies. You wrote:
“I still believe that actions can be primed, sometimes even by stimuli of which the person is unaware. There is adequate evidence for all the building blocks: semantic priming, significant processing of stimuli that are not consciously perceived, and ideo-motor activation. I see no reason to draw a sharp line between the priming of thoughts and the priming of actions.”
However, there is an important constraint on subliminal priming that needs to be taken into account. That is, they are very short lived, on the order of seconds. So any claims that a masked prime affects behavior for an extend period of time seems at odd with these more basic findings. Perhaps social priming is more powerful than basic cognitive findings, but it does raise questions. Here is a link to an old paper showing that masked *repetition* priming is short-lived. Presumably semantic effects will be even more transient.
Jeff Bowers
https://www.researchgate.net/profile/Kenneth_Forster/publication/232471563_Masked_repetition_priming_Lexical_activation_or_novel_memory_trace/links/56df0e5708ae9b93f79a89a2.pdf
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1. Hal Pashler
February 15, 2017 at 4:00 pm
Good point, Jeff. One might ask if this is something about repetition priming, but associative semantic priming is also fleeting. In our JEP:G paper failing to replicate money priming we noted
“For example, Becker, Moscovitch, Behrmann, and Joordens (1997) found that lexical decision priming effects disappeared if the prime and target were separated by more than 15 seconds, and similar findings were reported by Meyer, Schvaneveldt, and Ruddy (1972). In brief, classic priming effects are small and transient even if the prime and measure are strongly associated (e.g., NURSE-DOCTOR), whereas money priming effects are [purportedly] large and relatively long-lasting even when the prime and measure are seemingly unrelated (e.g., a sentence related to money and the desire to be alone).”
http://laplab.ucsd.edu/articles/RohrerPashlerHarris2015JEPG.pdf
Tuesday, February 21, 2017
Here's How You Buy Your Way Onto The New York Times Bestsellers List
Jeff Bercovici ,
FORBES STAFF
http://www.forbes.com/sites/jeffbercovici/2013/02/22/heres-how-you-buy-your-way-onto-the-new-york-times-bestsellers-list/#10ee05983fd1
I cover technology with an emphasis on social and digital media.
Opinions expressed by Forbes Contributors are their own.
Delivering Happiness (Photo credit: Wikipedia)
An endorsement from Oprah Winfrey. A film deal from Steven Spielberg. A debut at the top of The New York Times bestsellers list. These are the things every author craves most, and while the first two require the favor of a benevolent God, the third can be had by anyone with the ability to write a check -- a pretty big one.
ResultSource, a San Diego-based marketing consultancy, specializes in getting books onto bestseller lists, according to The Wall Street Journal. For clients willing to pay enough, it will even guarantee a No. 1 spot. It does this by taking bulk sales and breaking them up into more organic-looking individual purchases, defeating safeguards that are supposed to make it impossible to "buy" bestseller status.
And it's not cheap. Soren Kaplan, a business consultant and speaker, hired ResultSource to promote his book "Leapfrogging." Responding to the WSJ article on his website, Kaplan breaks out the economics of making the list.
With a $27.95 list price, I was told that the cost of each book would total about $23.50 after various retail discounts and including $3.99 for tax, handling and shipping. To ensure a spot on The Wall Street Journal’s bestseller list, I needed to obtain commitments from my clients for a minimum of 3000 books at about $23.50, a total of about $70,500. I would need to multiply these numbers by a factor of about three to hit The New York Times list.
So it would've cost more than $211,000, and that's before ResultSource's fee, which is typically more than $20,000. Kaplan settled for making the Journal's list, reaching the pre-sale figure of 3,000 by securing commitments from corporate clients, who agreed to buy copies as part of his speaking fees, and by buying copies for himself to resell at public appearances.
Kaplan expresses significant reservations about taking part in what is essentially a laundering operation aimed at deceiving the book-buying public into believing a title is more in-demand than it is.
"It’s no wonder few people in the industry want to talk about bestseller campaigns," he writes "Put bluntly, they allow people with enough money, contacts, and know-how to buy their way onto bestseller lists."
Yet ResultSource's methods aren't exactly secret. The company's website features an endorsement from Zappos CEO Tony Hsieh and a breakdown of the campaign it mounted behind his book "Delivering Happiness," which included a Groupon offering of 1,600 copies. Via a spokeswoman, Hsieh confirmed that he hired the firm and detailed the services it provided. (You can read Hsieh's full statement at the bottom of this post.)
Still, Amazon disapproves strongly enough of ResultSource's methods that it told WSJ it will no longer do business with the company. What about the publishers of the various bestsellers lists -- particularly the all-important New York Times list?
The Times's methodology (which you can find at the bottom of this page) samples sales from a diverse range of retail outlets, a measure specifically intended to weed out books whose sales surge is a product of artificial demand. Books that benefited from bulk sales are supposed to have a dagger icon next to them to denote that fact. Yet when Hsieh's book debuted on the list in 2009, it had no such symbol.
I called and emailed the Times with several questions, including whether it was aware before today of ResultSource's activities. Here's the reply I got from a spokeswoman: "The New York Times comprehensively tracks and tabulates the weekly unit sales of all titles reported by book retailers as their general interest bestsellers. We will not comment beyond our methodology on the other questions.
ResultSource CEO Kevin Small did not reply to a voicemail.
Here's Tony Hsieh's full message:
ResultSource booked us for various speaking events in many of our cities during our 2010 book tour, where we went to 23 cities over 3.5 months on the Delivering Happiness bus.
For part one of our trip, see:
http://www.youtube.com/watch?v=NtiIXo9Id-s
At many of those events, people paid to come watch me speak and receive an autographed copy of my book. ResultSource managed the speaking, book ordering, and distribution of the books for us during the tour. We're excited that the book has continued to do well over the years since the launch, and are also excited that the paperback version of the book will be coming out next month!
Since the book launch, "Delivering Happiness" has spun off into a company, and now has its own apparel line as part of its mission to help spread the Delivering Happiness message:
Kenneth Rapoza 4 years ago
the best seller list is nothing but a scam. Its like the author comments on book jackets; Jeff’s thriller makes Steven King look like the Mickey Mouse club circa 1950 — by some famous author who is your BFF and read a whole two chapters in your book, OR is repped by the same agent/publisher. Ive interviewed “best sellers” and they and their agents told me that they had no idea how they got there, because total sales were 20k. Admit it, we all thought that a best seller sold millions of copies, or at least a few hundred thousand. 20k? You and I have written blog posts that have had more readers than that!
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djvanderhoeven 4 years ago
At least Amazon’s process is much more transparently flawed (and I do mean that as a good thing.
Don’t know if you’re very familiar with the web comics community, but one of the more popular ones, Dinasaur Comics (www.qwantz.com) inspired an anthology of short stories written by readers and compiled by various web comic artists. It was called “Machine of Death”. Anyway, the authors used their considerable web tug to tell all of their readers to make sure to buy the book on Amazon on the a certain day. Guess what? A few thousand buys quickly knocked it up to a #1 best seller, and as a bonus, pissed off Glen Beck (whose book debuted below it on the Amazon list) at the same time.
For what’s it’s worth, I’m one of those readers/orderers, and it really was a very good book.
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gbooker 4 years ago
Yup, the same trick can be used to make a top selling record album.
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Marianne Canter 4 years ago
All best seller lists can be bought. Whether I’m in a bookstore or buying online, I avoid the Top Ten racks and search for selections recommended by friends or co-workers.
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Katherine Sears 4 years ago
And yet, it is the first thing people ask about my business (Booktrope Publishing): “how many bestsellers have you had?” My answer, “that depends”. Do you mean via Amazon, Barnes and Noble/Nook, the NYTimes? The latter who, in their policies, state they reserve the right to ignore books they deem unworthy (and who all acknowledge prefer companies who give them advertising dollars). Amazon, who makes no pretense of telling anyone how their lists are calculated at all – maybe it is fair, who knows? Barnes and Noble, who just says nothing at all. But, regardless of it all, readers do not care how a book made “the list”. They just want a trusted recommendation, and they don’t want to make an incremental effort to get it. Well, until there is an impartial source for the casual reader, those of us in the business will continue to do our best to work within the current flawed system, to bring great books to market and to the public’s attention.
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Elizabeth Vennekens-Kelly 4 years ago
An interesting article but a sad commentary on the industry. As an author whose book, was published by a boutique publisher, I know my chances are slim to none when it comes to making a best seller’s list.
If you want to help the ‘little guy/gal’ and/or have an interest in cultural differences, check out my book Subtle Differences, Big Faux Pas, available from Amazon.
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Peter de Jager 4 years ago
Ah yes Ethics – a case of “out of sight, out of mind” Welcome to the new world of marketing. I’ll pass
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ignacio sanabria 4 years ago
Meanwhile, we the authors, have to do the selling of our books by ourselves. Perhaps a book tour would be most effective.
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Teresa de Grosbois 4 years ago
It’s sad that there are outfits like this that advocate cheating the system. It really doesn’t serve the author or the industry in the long run. A foundation built on mud won’t stand. As someone who works with authors, I’d recommend running fast from anyone who would tell you to buy your way onto a list!
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