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I found this article rather fascinating mostly because I’ve long thought that “our technological and medical advances have removed most of the selection pressures acting upon us”. That such is not the case makes for interesting possibilities.

Human evolution is speeding up. Around 40,000 years ago our genes began to evolve much faster. By 5000 years ago they were evolving 30 to 40 times faster than ever before and it seems highly likely that we continue to evolve at this super speed today.

Our population explosion and rapidly changing lifestyles seem to be the drivers of this acceleration, the discovery of which contradicts the widely held notion that our technological and medical advances have removed most of the selection pressures acting upon us.

Modern times causing human evolution to accelerate - being-human - 14 December 2007 - New Scientist

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My personal resolution for the new year is that I will actually try to write down a larger fraction of the blog posts that are floating around in my head, especially the many that were born while I was sitting in my algorithms seminar.

The NYT has a travel feature on visiting the birthplace of Comte de Buffon, a contemporary and competitor to Carolus Linnaeus, who by this account played Hooke to Linnaeus’ Newton. Of course, I (and probably most of my readers) know Buffon not for his work in biology and the natural world, but for the famous problem that bears his name and by some accounts gave rise to the area of geometric probability.

The Buffon needle problem is this: Suppose we drop a needle of length l onto a grid with lines spaced d units apart. What is the probability that the needle touches a grid line ? (let’s assume for now that l <> d, the expression is more involved).

The Buffon’s needle problem is a textbook example of the area of geometric probability: doing probability theory on entities defined geometrically. This is a harder thing than one might imagine: as Bertrand demonstrated much later on, the very notion of a uniform random sample can be called into question. He showed this by posing a simple question:

Draw an equilateral triangle and circumscribe a circle around it. Pick a chord at random. What is the probability that the chord length is longer than the side of the triangle ?

It turned out that the “Pick a chord at random” step leads to all kinds of problems. Bertrand presented three different equally reasonable ways of picking a chord, and showed that each of the three ways led to a different probability. At the time, this was viewed as a paradox: it seemed strange that what appeared to be a well defined question would lead to three different answers. Of course, the modern view is that there is no paradox, merely a different choice of measure space to work with in each case.

But if that’s the case, is there a “natural” choice of measure ? One elegant way of thinking about this was to think of this as a physical process that must obey certain transformation invariants. This leads inexorably to notions like the Haar measure: can we assign a measure to subsets of a group that is invariant over left (or right) group actions ?

The Haar measure has practical utility for anyone working in geometry. Consider the problem of choosing a random rotation (this comes up in when doing Johnson-Lindenstrauss embeddings). In 2 dimensions, this is easy, since the space of rotations is the unit circle. However, in three dimensions or higher, it gets a bit trickier to define the correct measure to sample with respect to. Since rotations form a group, we really need a measure that is invariant under the group action, and a (unique upto scaling) Haar measure is guaranteed to exist in this case, yielding the desired measure to sample from (it’s actually fairly easy to generate a random rotation algorithmically: the easiest is to populate a matrix with independent normally distributed random variables, and then orthogonalize it).

But it all goes back to a needle, a grid, and a frustrated naturalist. Happy new year !

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Not long ago, I did a little piece on homeopathy. That post did not flatter the… ahem… medical science of homeopathy. Not surprisingly, my honesty and integrity were called into question– repeatedly. I was accused of rejecting homeopathy because I don’t understand science and because I have a prejudice against it. I was asked not to kill homeopathy– the blessing to mankind– because of my selfish motive and ignorance. I was accused of not wanting to read the literature and of basing my conclusions on one flawed study. These are all typical first blush reactions from supporters of faith-based and evidence challenged ideologies, hence my lack of surprise.

I was also challenged to give a single reason why one ought to reject homeopathy, and I was promised that my ignorance would be explained. I was sorely disappointed. My ignorance, alas, is still in full bloom; my errors, still uncorrected. So, by way of confession of sins, I thought I’d reveal the various and sundry sources of my misconceptions.

It reported that “any therapy that makes specific claims for being able to treat specific conditions should have evidence of being able to do this above and beyond the placebo effect”.

According to Professor Matthias Egger, from the University of Berne, and Swiss colleagues from Zurich University and a UK team at the University of Bristol, homoeopathy has no such evidence.

They compared 110 trials that looked at the effects of homoeopathy versus placebo with 110 trials of conventional medicines for the same medical disorders or diseases.

This included trials for the treatment of asthma, allergies and muscular problems, some large and some small.

For both homeopathy and conventional medicines, the smaller trials of lower quality showed more beneficial treatment effects than the larger trials.

However, when they looked at only the larger, high-quality trials, they found no convincing evidence that homeopathy worked any better than placebo.

Homoeopathy’s benefit questioned

There is a curious exchange at the end of that article.

However, the Lancet also reports that a draft report on homoeopathy by the World Health Organization says the majority of peer-reviewed scientific papers published over the past 40 years have demonstrated that homeopathy is superior to placebo in placebo-controlled trials.

Homoeopathy’s benefit questioned

The article notes that the draft report has been questions as being “overtly biased” and odd in that “that all of the trials cited happened to be positive” but the curious part is that “A spokeswoman from the Society of Homoeopaths” denies that placebo conrolled trials are valid tests of homeopathy. So WHO drafts a report stating that homeopathy is superior to placebos in placebo-controlled trials– that is, WHO drafts a report in favor of homeopathy– and a spokesperson for the Society of Homeopaths states that “that the placebo-controlled randomised controlled trial is not a fitting research tool with which to test homeopathy”? Why look a gift horse in the mouth? Why shoot the messenger? My guess: This spokesperson knows damn well that homeopathy doesn’t stand up under careful study. Accepting this WHO report would mean having to accept placebo-controlled trials that are not favorable to homeopathy.

Homeopathy remains one of the most controversial subjects in therapeutics. This article is an attempt to clarify its effectiveness based on recent systematic reviews. Electronic databases were searched for systematic reviews/meta-analysis on the subject. Seventeen articles fulfilled the inclusion/exclusion criteria. Six of them related to re-analyses of one landmark meta-analysis. Collectively they implied that the overall positive result of this meta-analysis is not supported by a critical analysis of the data. Eleven independent systematic reviews were located. Collectively they failed to provide strong evidence in favour of homeopathy. In particular, there was no condition which responds convincingly better to homeopathic treatment than to placebo or other control interventions. Similarly, there was no homeopathic remedy that was demonstrated to yield clinical effects that are convincingly different from placebo. It is concluded that the best clinical evidence for homeopathy available to date does not warrant positive recommendations for its use in clinical practice.

A systematic review of systematic reviews of homeopathy

The claim that homeopathic arnica is efficacious beyond a placebo effect is not supported by rigorous clinical trials.

Efficacy of Homeopathic Arnica

Conclusion: Homeopathic Arnica 30x is ineffective for muscle soreness following long-distance running.

Homeopathic Arnica 30x Is Ineffective for Muscle Soreness After Long-Distance Running: A Randomized, Double-Blind, Placebo-Controlled Trial.

A little good news… well, as good as it gets.

BACKGROUND: Homeopathy involves the use, in dilution, of substances which cause symptoms in their undiluted form. It is one of the most widespread forms of complementary medicines and is also used to treat asthma. OBJECTIVES: The objective of this review was to assess the effects of homeopathy in people with chronic stable asthma. SEARCH STRATEGY: We searched the Cochrane Airways Group trials register, the Cochrane Complementary Medicine Field trials register, the Glasgow Homeopathic Hospital database, the Muenchener Modell database and reference lists of articles. SELECTION CRITERIA: Randomised and possibly randomised trials of homeopathy for the treatment of stable chronic asthma, with observation periods of at least one week. DATA COLLECTION AND ANALYSIS: Data extraction was done by one reviewer and checked by the second reviewer. Trial quality was assessed by the reviewers. MAIN RESULTS: Three trials with a total of 154 people were included. These trials were all placebo-controlled and double-blind, but of variable quality. They used three different homeopathic treatments which precluded quantitative pooling of results. The standardised treatments in these trials are unlikely to represent common homeopathic practice, where treatment tends to be individualised. In one trial, severity of symptoms was lessened in the homeopathy group compared to the placebo group. In another trial, lung function measures and medication use showed improvement in the homeopathy group compared to the placebo group. The third trial found improvement in both the homeopathy and placebo groups, but no difference between the groups. REVIEWER’S CONCLUSIONS: There is not enough evidence to reliably assess the possible role of homeopathy in asthma. As well as randomised trials, there is a need for observational data to document the different methods of homeopathic prescribing and how patients respond.

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&uid=10796532&cmd=showdetailview&indexed=google

A little more good news.

Results. 50 papers report a significant benefit of homeopathy in at least one clinical outcome measure, 41 that fail to discern any inter-group differences, and two that describe an inferior response with homeopathy. Considering the relative number of research articles on the 35 different medical conditions in which such research has been carried out, the weight of evidence currently favours a positive treatment effect in eight: childhood diarrhoea, fibrositis, hayfever, influenza, pain (miscellaneous), side-effects of radio- or chemotherapy, sprains and upper respiratory tract infection. Based on published research to date, it seems unlikely that homeopathy is efficacious for headache, stroke or warts. Insufficient research prevents conclusions from being drawn about any other medical conditions.

Conclusions. The available research evidence emphasises the need for much more and better-directed research in homeopathy. A fresh agenda of enquiry should consider beyond (but include) the placebo-controlled trial. Each study should adopt research methods and outcome measurements linked to a question addressing the clinical significance of homeopathy’s effects.

The research evidence base for homeopathy: a fresh assessment of the literature

Hey! That one seems almost positive! “50 papers report a significant benefit of homeopathy…”? But look at the conclusion. Why such a weak conclusion following such a strong statement? Something doesn’t add up. Answer: “50 papers report a significant benefit of homeopathy in at least one clinical outcome measure…” doesn’t mean all that much. It means that “of the many things we tracked something somewhere got better”. Track enough stuff, and you’ll get lucky. This sounds to me like saying, “Yeah, the patient’s cancer didn’t change but his cholesterol got better. Ta-da! Success!”

Then take a look at who printed the article– the journal Homeopathy. This is the best it gets in a journal devoted to Homeopathy? That in itself is pretty telling.

Still more good news.

Conclusions: There is some evidence that homeopathic treatments are more effective than placebo; however, the strength of this evidence is low because of the low methodological quality of the trials. Studies of high methodological quality were more likely to be negative than the lower quality studies. Further high quality studies are needed to confirm these results.

Evidence of clinical efficacy of homeopathy

Low methodological quality?

Results While the methodological quality of the trials was highly variable, the majority had important shortcomings in reporting and/or methodology. Major problems in most trials were the description of allocation concealment and the reporting of drop-outs and withdrawals. There were relevant differences in single quality components between the different complementary therapies: For example, acupuncture trials reported adequate allocation concealment less often (6% versus 32% of homeopathy and 26% of herb trials), and trials on herbal extracts had better summary scores (mean score 3.12 versus 2.33 for homeopathy and 2.19 for acupuncture trials). Larger trials published more recently in journals listed in Medline and in English language scored significantly higher than trials not meeting these criteria.

Conclusion Trials of complementary therapies often have relevant methodological weaknesses. The type of weaknesses varies considerably across interventions.

The methodological quality of randomized controlled trials of homeopathy, herbal medicines and acupuncture

More bad news… In fact, here is a little bit of utter crack-pottery.

The notion of patient–practitioner–remedy (PPR) entanglement, previously proposed for homeopathy, is refined by adapting concepts derived from Greenberger, Horne, and Zeilinger’s treatment of three-particle entanglement (GHZ states), and a generalised version of quantum theory, called weak quantum theory (WQT). These suggest that for maximum PPR entanglement during the therapeutic encounter, the practitioner’s awareness needs to be directed inward as well as outward toward the patient, and that health and disease are mirror images of each other, similar to and represented by, the relationship of complex numbers to their complex conjugates.

Patient–practitioner–remedy (PPR) entanglement. Part 3. Refining the quantum metaphor for homeopathy

You have got to be joking? Quantum entanglement? Patient–practitioner–remedy entanglement? Entanglement that requires the practitioner to navel gaze? I think I’ll just get a chicken instead. Now that is a time tested method, and we all know it works.

But homeopathy is harmlesss, right? I mean, homeopaths are just distributing bloody sugar pills. What is the harm?

Dr Michelle Langdon risked the health of an 11-month-old girl and failed to get proper consent before using homeopathic medicine, the GMC’s professional conduct committee decided on Thursday.

Dr Langdon, a partner at the Brunswick Medical Centre in Camden, north London, treated the baby’s stomach infection by using a “dowsing” ritual to select a remedy, the hearing had heard.

Three-month ban for homeopathy GP

HOMOEOPATHS ARE prescribing their potions for malaria prevention, it was reported in The Times yesterday. This is worrying, even to Melanie Oxley of the Society of Homeopaths, because, as she says, there is no evidence that homoeopathy can guard against malaria.

Of course, malaria is not a special case. There is no evidence that homoeopathy can guard against or cure anything at all. A review of clinical trials of homoeopathy published in The Lancet in 2005 concluded that homoeopathy has no more than a placebo effect on patients.

Homoeopathy: voodoo on the NHS

And guess what?

Dr Ron Behrens, director of the travel clinic at the Hospital for Tropical Diseases, said: “We have treated people … who thought they were protected by homeopathic medicines and contracted malaria.”

In 2005 the Health Protection Agency issued a warning because of people falling seriously ill when using homeopathic remedies. Its advisory committee on malaria said: “Herbal remedies have not been tested for their ability to prevent or treat malaria and are not licensed for these uses … There is no scientific proof that homeopathic remedies are effective in either preventing or treating malaria.”

Homeopaths ‘endangering lives’ by offering malaria remedies

I wonder if those poor malaria sufferers were victims of practitioners who didn’t quantum entangle correctly?

So… I apologize. Homeopathy works and I’m just a prejudiced bastard. Oh… and I’m ignorant.

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Wer den Fernseher so sehr liebt, daß er darüber nicht nur den Haushalt vergißt, sondern auch meinem kleinen Liebling nicht mehr in ausreichendem Maße dienstbar ist, der scheidet in Muttis Augen als gute Ehefrau vollkommen aus.

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I’ve been thinking a lot about grade inflation over the past few months, mostly because I am on the front lines of it. That is, I’ve been grading papers– a lot of them. I’ve been through 500 or so pages of freshman, mostly, attempts at writing philosophy… well, let me rephrase that… attempts at thinking for the first time in their short lives. Of course, each student is having thoughts they’ve never had before and each and every one of them thinks these thoughts are original and genius. They are neither.

Mostly, I don’t say this critically. I think that an obsession with ‘unique’ is intellectual poison. We ought to be concerned more with ‘accurate’ and, frankly, if someone else has it right you can’t be both ‘unique’ and ‘accurate’ about that thing. The ‘genius’ part I do find annoying, but the brunt of the criticism isn’t aimed at the kids. There seems to be something– self esteem issues perhaps?– embedded in the educational system that leads these kids to believe that every one of their little brain farts is exciting and valuable. They aren’t, and it is a dis-service to everyone to leave them with that impression.

And so to my topic of grade inflation.

Teachers who push most students above a C grade only defeat the purpose of grades to motivate students to do better or to help parents and employers to distinguish abilities. Once graduates enter the job market, they discover they can’t bank on those undeserved grades.

Licking Grade Inflation

Like I said, “it is a dis-service to everyone”. Why expect careful thought from someone whose sloppy thinking has never been challenged?

But there are problems.

Professors get the message pretty quickly that “A” students give them good reviews that lead to tenure and raises - while the opposite occurs for tough graders.

Licking Grade Inflation

Not to mention that…

… the truly outstanding and industrious student is wronged. Grading is about fundamental fairness. Not everyone performs exceptionally well and should not be deceived into thinking they have. Nobody’s achievements should be cheapened by a leveling of grades.

Grade inflation is not a victimless crime

And so to me. The rules of thumb given me for issuing those grades prevented me from giving the grade actually deserved. I feel guilty.

Maybe, though, it isn’t so bad. Perhaps there is hope for anyone willing to face the whining of students who got a D, deserved an F, and think they earned an A.

Despite dozens of empirical studies to the contrary, fear that students will retaliate on their course evaluations is the myth fueling grade inflation that is hardest to debunk. Faculty often are convinced that their popularity and even their jobs are at risk, that somehow they can buy respect with higher grades, and that students are so easily duped by undeserved grades that they will return the favor with higher evaluations.

Grade inflation is not a victimless crime

Still haven’t explained my title have I? Someone I know relates this problem to the tendency of students to view grades/diplomas as commodities to be purchased. Pay your money; get your product. One wonders if the same logic applies to, say, pilot’s licenses.

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