Comments for What is a Good Study? Questions You Can Ask at http://www.randi.org/site , comment 1 to 15 out of 15 comments http://www.randi.org/site Wed, 19 Jun 2013 09:48:39 +0100 FeedCreator 1.7.3 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-25002 @Davis You are not a skeptic, you are a denier. You are applying Kyle's second step without haven done the first one. - jmarley42 Fri, 16 Mar 2012 17:50:53 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-25001 @Davis: You might want to catch up on the past couple of decades of development in wind and solar power: Both are comparable in costs to other forms of power, (wind is already cheaper than nuclear, solar only slightly more expensive), with costs that are falling. As a pair they make for a good source of base generation, wind tends to generate more at night, when you lose solar-photovoltaic[1]. While production is variable, over large areas it averages out and it will be easy enough to design deployment so as to be sufficient even during rare slumps. Excess power generation is already a solved problem, just build something that works as a power sink[2], (wind generation can also be reduced by feathering the turbines). Look at places like Germany and Texas to see what they really can do. Texas is currently getting about 20% of its electricity from wind, (with the limitation being the need for more power lines), while Germany has seen solar cut its electricity prices by 10%, (40% during the demand peak in the afternoon), and sometimes is getting so much power from wind that they have to start giving it away, (electricity prices in Germany have occasionally gone negative). [1] Solar-thermal delivers power 24/7. [2] Traditionally this had been done with aluminum refineries, although in this case I would suggest Fischer-Tropsch plants to turn biomass into things like gasoline. - rwpikul Fri, 16 Mar 2012 15:46:00 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24999 The article gives the impression that if sample size is not large enough, a study is not valid whatever p is. I think that's misleading for people who do not have a solid understanding of statistics. Sample size is already taken into account when calculating p, so if p passes statistical muster it is incorrect to look at sample size to further prove or disprove the study. Obviously if the effect studied is real, increasing the sample size will improve p (lower p). I also completely side with the post written by mdw on 3/15/12. Among other things, the article doesn't help statistically-less-educated readers, to understand that the magnitude of the effect is paramount. One may have an extremely low effect, say 1% with a large population, showing impressive statistics (say p=0.001), which would be completely irrelevant. Conversely one may have a sizeable effect, say 10% with a small sample, and poor statistics (say p=0.1). I think if I had to decide where to allocate research money, or what to learn more about, I would probably go for the second study. - gciriani Fri, 16 Mar 2012 05:34:40 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24998 I was being sarcastic regarding volcanoes. My point is this: Global warming is a much a political issue as it is a scientific one. Before we "penalize" prosperous countries (the evil USA of course), we need to be sure the above questions (and plenty more) are answered fairly and as accurately as possible. The liberal agenda despises oil and believes it be the most harmful resource we have ever tapped into. They disregard the millions of products, jobs and services we have BECAUSE of oil. That being said, we ALL would love to abandon oil today,but its just not possible. Wind and solar are a joke. So you must forgive me for being "skeptical" about this issue. I am merely trying to do what this site encourages. - Davis Fri, 16 Mar 2012 04:27:04 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24997 @Davis: Humans contribute a hundred times more CO2 than volcanoes. Looking at ourselves is easier than trying to control nature. Human-caused pollution is the main problem, and we should try to fix it. - Fanitullen Fri, 16 Mar 2012 00:35:29 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24996 @lytrigian: I wouldn't use Kiribati as an example of the effects of global warming; the immediate threat to the islands is due to the action of the waves, not rising sea levels as the news sources love to claim, and the waves haven't been linked to global warming. The dwindling glaciers and retreating ice sheets are a different story - we haven't had so little ice in the summers for a few tens of thousands of years. A century ago the "northwest passages" would only open up occasionally, but there have been navigable channels every summer for the past 6 years. - MadScientist Thu, 15 Mar 2012 21:53:35 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24995 My mind had de-blanked. "Surrogate endpoint" (vs "clinical endpoint") is the term I was looking for. http://en.wikipedia.org/wiki/Surrogate_endpoint - mdw Thu, 15 Mar 2012 20:15:50 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24994 A nitpick: "The statistics turn out that if you have less than around 1,024 people for a nationwide study, the margin or error exponentially increases beyond three percent." No, it increases as a *power law*: the margin of error is proportional to one over the square root of the sample size. Also note that the required sample size varies greatly with the size of the effect. For example, we take a sample of 5 people and have them jump from a plane without a parachute. All five died within minutes of jumping. We know that if we choose a random person at random point in their life, the odds of them dying within a few minutes of our chosen time point is extremely low, so 5 out of 5 jumpers dying is highly significant. Something you missed: Does the study report real end points or substitute end points? ("Substitute" isn't the right word, but my mind has blanked on the correct term.) E.g. for a heart medication, the real end point is "did the experiment group suffer fewer heart attacks?" while a substitute end point is "did the experiment group have lower blood cholesterol?" Real end points are to be preferred where possible, but sometimes they are impractical. Be somewhat wary of substitute end points. Briefly on the global climate change debate: Note the above comment on sample size and effect size - a few decades of 'experiment' is not necessarily insufficient to reach a conclusion. (I don't know the data well enough to say more than this.) Climate change is not based solely on a few points on the 'hockey stick' temperature graph, any more than evolution is based solely on a handful of fossils. That we have greatly increased the atmospheric CO2 content by burning fossil fuels is beyond question. It is proven by multiple lines of reasoning, including carbon isotope ratios, comparison with air bubbles in ancient ice, and simply by calculating the quantity of CO2 we're releasing and comparing it to the background level and the lifetime of carbon in the atmosphere. (If you insist on statistics, go look at how many atoms they counted in the isotope ratio measurements.) Extremely well established physics says that with more atmospheric CO2, the greenhouse effect will cause warming. It is only when we try to move beyond this point that things get complicated - what climate feedback loops might cause the warming to be more or less than a simple calculation would indicate? Now we get into a mess of albedo, snowfall, cloud cover, ocean currents, vegetation etc. It is like I've just shot a bullet at somebody, and assert that things are about to go badly for them. The basic physics is very much on my side, but specific circumstances (e.g. bullet proof vest, or I shot at their reflection by mistake) may invalidate my prediction. However, my case is strong enough that it is now up to those who think the bullet will be harmless to justify that view. For climate change, the scientists have looked into these messy details to see if they change the expectation from basic physics. This leads to a lot of fiddling at the margins of the prediction - this effect makes warming a bit greater, that effect a bit smaller, reanalysis of some third effect shows it is more or less efficient than the original analysis claimed. However, the very strong scientific consensus is that after all of these effects are accounted for, the warming will still be significant (in both the statistical and common use of the word.) - mdw Thu, 15 Mar 2012 20:13:21 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24992 Great article, definitely going to use this to teach my kids. - vanadamme Thu, 15 Mar 2012 18:33:43 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24991 Guess we had better outlaw volcanoes then. And let me guess. You are a liberal aren't you? - Davis Thu, 15 Mar 2012 16:19:12 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24990 "So you are saying global warming "scientists" have never been guilty of changing data and reporting false results?" There is no reason to doubt the current research. For the current consensus to be based on falsified data would take world-wide conspiracy of staggering proportions, involving hundreds of agencies. - sailor Thu, 15 Mar 2012 16:13:43 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24988 It's funny how global warming denialists keep bringing up the University of East Anglia thing, as if the entire scientific consensus within Climatology that anthropogenic global warming is in fact occurring stands or falls by this single research group. EVEN IF it were true that they falsified data -- it isn't -- it wouldn't affect the observations over other climatologists all over the world. It's at least as much a problem that denialists are willing to commit international crimes in order to foster a smear campaign, that scientists within the climatology community may or may not have used less than optimal analysis methods. (This was about the only real issue found, and correcting it doesn't significantly change the result.) Anthropogenic global warming isn't happening? Tell it to the residents of Kiribati. - lytrigian Thu, 15 Mar 2012 14:51:21 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24986 So you are saying global warming "scientists" have never been guilty of changing data and reporting false results? - Davis Thu, 15 Mar 2012 11:40:20 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24985 Question 1 "Is the study large enough to pass statistical muster?" No, you cant take a snap shot of a few years against billions and get an accurate answer In fact we know much about climate going back thousands of years. Direct measurement of temperature is not the only way, there are ice core samples, tree rings and other material. Climate scientists have done a lot of work on computer models and analyzing all the possible inputs to the current trends. It is quite clear that the climate is warming, and it is also quite clear that the only obvious reason for this is greenhouse gasses. Lucky you denialists did not hold sway over the argument about the ozone layer or it would still be getting worst instead of repairing itself nicely. - sailor Thu, 15 Mar 2012 11:25:36 +0100 http://www.randi.org/site/index.php/swift-blog/1658-what-is-a-good-study-questions-you-can-ask.html#comment-24983 Kyle hit the nail on the head with these questions. And when you use them to test the belief of man made global warming, it is quite telling. Question 1 "Is the study large enough to pass statistical muster?" No, you cant take a snap shot of a few years against billions and get an accurate answer. Question 2: "Could unintentional bias have affected the results?" Absolutely. Strong political and religious (or non-relgious) beliefs can cause bias worse than most people would like to admit. I could go on but I think you get the picture. Scientists can unknowingly (and sometimes knowingly) massage the data to get a desired result. - Davis Thu, 15 Mar 2012 10:54:07 +0100