Precision in language

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

Some time ago, a commenter to this blog sent me a private email expressing this view:

Have you ever noticed people say “Do you believe in evolution?” just as you would ask “Do you believe in God?” as if both schools of thought have equal footing? I respect others’ religious beliefs as I realize I cannot disprove God just as anyone cannot prove His existence, but given the amount of evidence for evolution, shouldn’t we insist on asking “Do you accept evolution?”

It may just be semantics, but I feel that the latter wording carries an implied affirmation just as “Do you accept that 2+2=4?” carries a different meaning than “Do you believe 2+2=4?”

I guess the point I’m trying to make is that by stating something as a belief, it opens the debate to the possibility that something is untrue. While this may fine for discussions of religion, shouldn’t the scientific community be more insistent that a theory well supported by physical evidence, such as evolution, is not up for debate?

It’s a good point. To be fair, scientists themselves are partly responsible for this confusion because we also say that we “believe” in this or that scientific theory, and one cannot blame the general public from picking up on that terminology. What is important to realize, though, is that the word ‘believe’ is being used by scientists in a different sense from the way it is used in religion.

The late and deeply lamented Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy, who called himself a “radical atheist” puts it nicely (thanks to onegoodmove):

First of all I do not believe-that-there-is-not-a-god. I don’t see what belief has got to do with it. I believe or don’t believe my four-year old daughter when she tells me that she didn’t make that mess on the floor. I believe in justice and fair play (though I don’t know exactly how we achieve them, other than by continually trying against all possible odds of success). I also believe that England should enter the European Monetary Union. I am not remotely enough of an economist to argue the issue vigorously with someone who is, but what little I do know, reinforced with a hefty dollop of gut feeling, strongly suggests to me that it’s the right course. I could very easily turn out to be wrong, and I know that. These seem to me to be legitimate uses for the word believe. As a carapace for the protection of irrational notions from legitimate questions, however, I think that the word has a lot of mischief to answer for. So, I do not believe-that-there-is-no-god. I am, however, convinced that there is no god, which is a totally different stance. . .

There is such a thing as the burden of proof, and in the case of god, as in the case of the composition of the moon, this has shifted radically. God used to be the best explanation we’d got, and we’ve now got vastly better ones. God is no longer an explanation of anything, but has instead become something that would itself need an insurmountable amount of explaining…

Well, in history, even though the understanding of events, of cause and effect, is a matter of interpretation, and even though interpretation is in many ways a matter of opinion, nevertheless those opinions and interpretations are honed to within an inch of their lives in the withering crossfire of argument and counterargument, and those that are still standing are then subjected to a whole new round of challenges of fact and logic from the next generation of historians – and so on. All opinions are not equal. Some are a very great more robust, sophisticated and well supported in logic and argument than others.

When someone says that they believe in god, they mean that they believe something in the absence of, or even counter to, the evidence, and even to reason and logic. When scientists say they believe a particular theory, they mean that they believe that theory because of the evidence and reason and logic, and the more evidence there is, and the better the reasoning behind it, the more strongly they believe it. Scientists use the word ‘belief’ the way Adams says, as a kind of synonym for ‘convinced,’ because we know that no scientific theory can be proven with 100% certainty and so we have to accept things even in the face of this remaining doubt. But the word ‘believe’ definitely does not carry the same meaning in the two contexts.

This can lead to the generation of confusion as warned by the commenter but what can we do about it? One option is, as was suggested, to use different words, with scientists avoiding use of the word ‘believe.’ I would have agreed with this some years ago but I am becoming increasingly doubtful that we can control the way that words are used.

For example, there was a time when I used to be on a crusade against the erroneous use of the word ‘unique’. The Oxford English Dictionary is pretty clear about what this word means:

  • Of which there is only one; one and no other; single, sole, solitary.
  • That is or forms the only one of its kind; having no like or equal; standing alone in comparison with others, freq. by reason of superior excellence; unequalled, unparalleled, unrivalled.
  • Formed or consisting of one or a single thing
  • A thing of which there is only one example, copy, or specimen; esp., in early use, a coin or medal of this class.
  • A thing, fact, or circumstance which by reason of exceptional or special qualities stands alone and is without equal or parallel in its kind.

It means, in short, one of a kind, so something is either unique or it is not. There are no in-betweens. And yet, you often find people saying things like “quite unique” or “very unique” or “almost unique.” I used to try and correct this but have given up. Clearly, people in general think that unique means something like “rare” and I don’t know that we can ever change this even if we all become annoying pedants, correcting people all the time, avoided at parties because of our pursuit of linguistic purity.

Some battles, such as with the word unique are, I believe, lost for good and I expect the OED to add the new meaning of ‘rare’ some time in the near future. It is a pity because then we would then be left with no word with the unique meaning of ‘unique’, but there we are. We would have to say something like ‘absolutely unique’ to convey the meaning once reserved for just ‘unique.’

In science too we often use words with precise operational meanings while the same words are used in everyday language with much looser meanings. For example, in physics the word ‘velocity’ is defined operationally by the situation when you have an object moving along a ruler and, at two points along its motion, you take ruler readings and clock readings, where the clocks are located at the points where the ruler readings are taken, and have been previously synchronized. Then the velocity of the moving object is the number you get when you take the difference between the two ruler readings and divide by the difference between the two clock readings.

Most people (especially sports commentators) have no idea of this precise meaning when they use the word velocity in everyday language, and often use the word synonymously with speed or, even worse, acceleration, although those concepts have different operational meanings. Even students who have taken physics courses find it hard to use the word in its strict operational sense.

Take, for another example, the word ‘theory’. By now, as a result of the intelligent design creationism (IDC) controversy, everyone should be aware that the way this word is used by scientists is quite different from its everyday use. In science, a theory is a powerful explanatory construct. Science depends crucially on its theories because they are the things that give it is predictive power. “There is nothing so practical as a good theory” as Kurt Lewin famously said. But in everyday language, the word theory is used as meaning ‘not factual,’ something that can be false or ignored.

I don’t think that we can solve this problem by putting constraints on how words can be used. English is a wonderful language precisely because it grows and evolves and trying to fix the meanings of words too rigidly would perhaps be stultifying. I now think that we need to change our tactics.

I think that once the meanings of words enter mainstream consciousness we will not be successful in trying to restrict their meanings beyond their generally accepted usage. What we can do is to make people aware that all words have varying meanings depending on the context, and that scientific and other academic contexts tend to require very precise meanings in order to minimize ambiguity.

Heidi Cool has a nice entry where she talks about the importance of being aware of when you are using specialized vocabulary, and the need to know your audience when speaking or writing, so that some of the pitfalls arising from the imprecise use of words can be avoided.

We have to realize though that despite our best efforts, we can never be sure that the meaning that we intend to convey by our words is the same as the meaning constructed in the minds of the reader or listener. Words always contain an inherent ambiguity that allows the ideas expressed by them to be interpreted differently.

I used to be surprised when people read the stuff I wrote and got a different meaning than I had intended. No longer. I now realize that there is always some residual ambiguity in words that cannot be overcome. While we can and should strive for maximum precision, we can never be totally unambiguous.

I agree with philosopher Karl Popper when he said, “It is impossible to speak in such a way that you cannot be misunderstood.” The best we can hope for is to have some sort or negotiated consensus on the meanings of ideas.

POST SCRIPT: Huckabee and Paul

Alexander Cockburn discusses why Mike Huckabee and Ron Paul are the two most interesting candidates on the Republican side.

Atheism and meaning

(As is my custom this time of year, I am taking some time off from writing new posts and instead reposting some old favorites (often edited and updated) for the benefit of those who missed them the first time around or have forgotten them. The POST SCRIPTS will generally be new. New posts will start again on Monday, January 5, 2009. Today’s post originally appeared in October 2007.)

People often think that atheists do not have a life affirming philosophy. They have sometimes taken the quote by prominent atheist Richard Dawkins (Scientific American November 1995, p. 85) that “The universe that we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but pitiless indifference” to argue that atheism leads to a philosophy of hopelessness and despair. I have heard several talks by intelligent design creationism advocate Michael Behe and he repeatedly uses the quote to get a laugh at the expense of atheism by saying that Dawkins must be a real downer at parties. But anyone who has seen interviews with Dawkins and read his writings will come away with the contrary impression, that he is a witty, courteous, and engaging man with a mischievous sense of humor. One can well imagine him livening up any party. Dawkins was merely making a factual observation about the nature of the universe, saying that it is futile to try and obtain our meaning and purpose externally from the universe, although we can observe it with awe and wonder. We can, and should, construct meaning and purpose for our lives.
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Opinion polls and statistics

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

As the 2008 election season gets into high gear, we will get inundated with the results of opinion polls. Many of our public policies are strongly influenced by these polls, with politicians paying close attention to them before speaking out.

But while people are inundated with opinion polls, there is still considerable misunderstanding about how they work. Especially during elections, when there are polls practically every day, one often hears people expressing skepticism about polls, saying that they feel the polls are not representative because they, personally, and all the people they know, have never been asked their opinion. Surely, they reason, if so many polls are done, every person should get a shot at answering these surveys? That fact that no pollster has contacted them or their friends and families seem to make the poll results suspect in their eyes, as if the pollsters are using some highly selective group of people to ask and leaving out ‘ordinary’ people.

This betrays a misunderstanding of statistics and the sampling size needed to get good results. The so-called “margin of error” quoted by statisticians is found by dividing 100 by the square root of the size of the sample. So if you have a sample of 100, then the margin of error is 10%. If you have a sample size of 625, then the margin of error drops sharply to 4%. If you have a sample size of 1111, the margin of error becomes 3%. To get to 2% requires a sample size of 2500.

Clearly you would like your margin of error to be as small as possible, which argues for large samples, but your sample sizes are limited by the cost and time involved in surveying people, so trade offs have to be made. Most pollsters use samples of about 1000, and quote margins of error of 3%.

One interesting point is that there are statistical theorems that say that the sample size needed to get a certain margin of error does not depend on the size of the whole population (for large enough populations, say over 100,000). So a sample size of 1000 is sufficient for Cuyahoga County, the state of Ohio, or the whole USA. This explains why any given individual is highly unlikely to be polled. Since the population of the US is close to 300 million, any one of the 1000 people I may personally know has only a 0.00033% probability of being contacted.

We know that a poll tells us that 54% of Americans say that “I do not think human beings developed from earlier species.” The sample size was 1000, which means a margin of error of about 3%. Statistically, this means that there is a 95% chance that the “true” percentage of people who agree with that statement (i.e., the number we would get if could actually ask each and every person on the country) lies somewhere between 51% and 57%.

Certain assumptions and precautions go into interpreting these results. The first assumption is that the people polled are a truly random sample of the population. If you randomly contact people, that may not be true. You may, for example, end up with more women than men, or you may have contacted more old people or registered Republicans than are in the general population. If, from census and other data, you know the correct proportions of the various subpopulations in your survey, then this kind of skewing can be adjusted for by changing the weight of the contributions from each subgroup to match the actual population distribution.

With political polls, sometimes people complain that the sample sizes of Democrats and Republicans are not equal and that thus the poll is biased. But that difference is usually because the number of people who are officially registered as belonging to those parties are not equal.

But sometimes pollsters also quote the results for the subpopulations in their samples, and since the subsamples are smaller, the breakdown data has greater margin of error than the results for the full sample, though you are often not explicitly told this. For example, the above-mentioned survey says that 59% of people who had high school education or less agreed that “I do not think human beings developed from earlier species.” But the number of people in the sample who fit that description is 407, which means that there is a 5% uncertainty in the result for that subgroup, unlike the 3% for the full sample of 1000.

But a more serious source of uncertainty these days is that many people refuse to answer pollsters when they call and it is not possible to adjust for the views of those who refuse. So although the pollsters do have data on the numbers of persons who hang up on them or otherwise refuse to answer, they do not know if such people are more likely or less likely to think that humans developed from earlier species. So they cannot adjust for this factor. They have to simply assume that if those non-responders had answered, their responses would have been in line with those who actually did respond.

Then there may be people who do not answer honestly for whatever reason or are just playing the fool. They are also hard to adjust for. This is why I am somewhat more skeptical of surveys of teens on various topics. It seems to me that teenagers are just the right age to get enjoyment from deliberately answering questions in exotic ways.

These kinds of biases are hard, if not impossible, to compensate for, though in serious research the researchers try to put in extra questions that can help gauge whether people are answering honestly. But opinion polls, which have to be done quickly and cheaply, are not likely to go to all that trouble

Because of such reasons, polls like the Harris poll issue this disclaimer at the end:

In theory, with probability samples of this size, one could say with 95 percent certainty that the overall results have a sampling error of plus or minus 3 percentage points of what they would be if the entire U.S. adult population had been polled with complete accuracy. Sampling error for subsamples is higher and varies. Unfortunately, there are several other possible sources of error in all polls or surveys that are probably more serious than theoretical calculations of sampling error. They include refusals to be interviewed (nonresponse), question wording and question order, and weighting. It is impossible to quantify the errors that may result from these factors.

For all these reasons, one should take the quoted margins of error, which are based purely on sample size, with a considerable amount of salt.

There is one last point I want to make concerning a popular misconception propagated by news reporters during elections. If an opinion poll says that a sample of 1000 voters has candidate A with 51% support and candidate B with 49%, then since the margin of error (3%) is greater than the percentage of votes separating the candidates (2%), the reporters will often say that the race is a “statistical dead heat,” implying that the two candidates have equal chances of winning.

Actually, this is not true. What those numbers imply (using math that I won’t give here) is that there is about a 75% chance that candidate A truly does lead candidate B, while candidate B has only a 25% chance of being ahead. So when one candidate is three times as likely as the other to win, it is highly misleading to say that the race is a “dead heat.”

POST SCRIPT: Inflated value of religion

Many people have an inflated sense of the value of religion that simply falls apart on close examination. For example, Mike Huckabee said the following: “The Ten Commandments form the basis of most of our laws and therefore, you know if you look through them does anybody find anything there that would be all that objectionable? I don’t think most people would if they actually read them.”

He says this as if it is obviously true. But Ed Brayton shows how absurd this is.

The joy of free thinking

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

There is scarcely a week that does not pass without some interesting new scientific discovery about the nature of life. You open the newspaper and read of observations of light emitted by distant stars from the very edges of the known universe, light that must have been emitted almost at the very beginning, over ten billion years ago. Such research puts us in touch with our own cosmic beginnings.

Just recently there was the discovery of the fossils a possible new Hobbit-like people who lived in a remote island in the Indonesian archipelago about 18,000 years ago. Then there was the discovery in China of an almost perfectly preserved bowl of noodles that is about the 4,000 years old. Discoveries like these shed light on how evolution works and how human society evolved. And then the discovery of Tiktaalik, the 375-million year-old fossil that seems like an intermediary between sea and land animals.

Similarly, the discoveries that come from studies of DNA tell us a lot about where humans probably originated, how we are all related to one another and how, despite our common origins, the species spread over the Earth and diversified. The fact (according to the September 21, 2005 issue of The Washington Post) that we share nearly 99 percent of our DNA with chimpanzees, lend further strong support (not that it needed it) to the evolutionary idea that chimpanzees and humans share a common ancestry. (The approximately one percent difference, according to The Daily Show, is what causes human beings to kill each other!)

I enjoy reading things like this because it reminds me of Charles Darwin’s central idea, that we are all linked together in one great biological evolutionary tree, with the various animal species being our cousins, and even seemingly insignificant things like worms and bacteria having common ancestors with us, however distantly in the past that might have happened. Some people may find the idea of being related to a monkey repulsive but I think it is fascinating. The ability of science to investigate, to find new relationships, to explore and conjecture and come up with answers to old questions as well as create new questions to investigate is one of its greatest qualities.

And for me, personally, being an atheist makes that joy completely unalloyed. Shafars (i.e., secularists, humanists, atheists, freethinkers, agnostics, and rationalists), as well as religious people who interpret their religious texts metaphorically and not literally, do not have any concerns when new headlines describing a new scientific discovery are reported in the news. They do not have to worry whether any new fact will contradict a deeply held religious belief. They do not have to worry about whether they need to reconcile the new information with any unchanging religious text.

On the other hand, the same news items that give us fascinating glimpses of scientific discoveries undoubtedly create fresh headaches for all religious people, and especially those whose beliefs are based on literal readings of religious texts, because each new discovery has to be explained away if it disagrees with some dogma. There are people who devote their entire lives to this kind of apologetics, to ensure that their religious beliefs are made compatible with science. The website Answers in Genesis, for example, is devoted to making Young-Earth creationism (YEC) credible. So it goes to great lengths to show that the earth is less that 10,000 years old, all the animals could have fitted into Noah’s Ark, and that dinosaurs lived at the same time as humans.

One has to admire the tenacity of such people, their willingness to devote enormous amounts of time, sometimes their whole lives, to find support for a belief structure that is continuously under siege from new scientific discoveries. It must feel like trying to hold back the tide. (See this site which heroically tries to fit into a 10,000 year old universe model the astrophysical data received from light emitted by stars that are billions of light years away.)

Of course, scientific discoveries come too thick and fast for even the most determined religious apologists to keep up. So they tend to focus only on explaining away a few questions, the kinds of questions that the lay public is likely to be most concerned about, such as whether dinosaurs existed concurrently with humans, the ages of the universe and the Earth, whether the size of the Ark was sufficient to accommodate all the species, how Noah coped with the logistical problems of feeding all the animals and disposing of the waste, how Adam and Eve’s children could multiply without there already being other people around or indulging in incest, and so on.

But the rest of us don’t have to worry about any of that stuff and so can enjoy new scientific discoveries without any cares, and follow them wherever they lead. It is nice to know that one can throw wide open the windows of knowledge and let anything blow in, clearing out the cobwebs of old ideas and freshening up the recesses of the mind.

It is a wonderful and exhilarating feeling.

So for this new year, I wish all the readers of this blog the joys of free thinking. May your thoughts not be hobbled by superstitions ancient or modern.

POST SCRIPT: The 50 Most Loathsome People in America

I usually avoid reading all the lists of best, worst, etc. that come out this time of year, but this one is actually very good.

Here’s #29 on the list Dinesh D’Souza:

Charges: Wrote a book blaming 9/11 on — who else? — liberals, because if we didn’t live in a free society, then fundamentalists wouldn’t dislike us so. Even conservative nuts blasted D’Souza’s empathy for poor al Qaeda. Lately, he’s been engaging prominent atheists in debates, revealing himself to be a pseudointellectual ass, and then declaring victory. D’Souza’s master plan for attacking atheism is the ridiculous Pascal’s wager: Atheists could be wrong, and then they’d go to hell, but if the religious are wrong, then they suffer no ill effect — aside from living their lives in delusion, of course. And possibly going to someone else’s hell for believing the wrong religion. D’Souza seems to think that if he speaks more loudly and rapidly than his opponent, he is winning, but his arguments are weak and idiotic, and he never even attempts to truly debate the existence of any god, which is the ostensible point of these debates. Instead, he likes to compare body counts — Stalin and Mao killed more than the religious leaders of their time — rather than actually debate whether there is a God, or for that matter a Jesus. This, of course, is because there is no case to be made.

Exhibit A: “[Atheists] are God-haters… I don’t believe in unicorns, but then I haven’t written any books called The End of Unicorns, Unicorns are Not Great, or The Unicorn Delusion.” But what if everyone you met did believe in unicorns, and not only that, but worshiped a unicorn, held a book about unicorns to be the divine truth of the universe, invoked unicorns in political contexts, and speechified about how non-believers were indecent people waging a war on morality, which could only be predicated on the unquestioning belief in unicorns? Then, maybe, D’Souza would think about writing that book. But of course, that’s not really true, because if that was the world we lived in, then Dinesh D’Souza would believe in unicorns.

Sentence: Spanish inquisition.