1. A control is a part of an experiment in which the variable being tested (the experimental variable) is left alone.
2. Thus you can compare the control with the experimental group, in which you fiddle with the variable that you want to isolate and test (and only that variable).
   1. In a clinical trial, which is the best-known kind of experiment to the general public, we would divide a group of test subjects into two groups. In this example, all would have the flu, or be at risk for catching one. . .
   2. One group would get, say, Doctor Waggoner's Miracle Cure; the other group would get nothing.
   3. If the people who got the Miracle Cure got over their illness faster than those who did not, we would have confirmed the hypothesis.
   4. Note that we would have to match the experimental and control groups as closely as possible (same ages, genders, races, etc.)
      1. Watch for the placebo effect! In drug trials, people have been found to feel better, and get better, if they think they're getting an effective medicine (even if what they're getting is useless).
      2. To avoid this, in a clinical trial, both experimental and control groups receive a treatment, but the control group gets something completely ineffective (say, a pill made of sugar, or an injection of mild saltwater solution). This ineffective treatment is a placebo.
      3. Drug tests are usually done double-blind: Neither the patient, nor the doctor who gives the treatment, knows who is getting the placebo and who is getting the real drug.

II. An untestable statement is not scientific and has no place in science. (This doesn't mean that untestable statements are useless or meaningless or wrong -- just that you can't use the "toolkit" of science to work with them.) Examples include (but are not limited to):

1. Aesthetics ("Beethoven's Seventh Symphony is more beautiful than Brahms's First Symphony.")
2. Imprecise statements ("Like, when the sun shines on plants, like, stuff happens and, like, so they're all, like, kind of growing. Like, y'know?")
   1. Science isn't the same as mathematics. . .
   2. . . . but many branches of science use mathematics as a language, because it forces you to be precise about what you mean. . .
   3. . . . and the same applies to scientific vocabulary. It's a pain in the neck to learn all the long words that scientists often use -- but the reason they're useful is because they have very precise meanings, and they let you state precise, testable hypotheses.
      • This hypothesis sounds complex. . . but once you learn what the words mean -- once you learn the code -- it's very testable, because it means something very specific: "LSD is an agonist of the 5HT2A and 5HT2C serotonin receptors in the brain."
      • On the other hand, "LSD, like, wow, man. . . like, you see stuff, and it's like, oh, wow. . ." is easy to understand -- but it's too vague to be tested, and so it's not scientific.
3. Subjective statements ("There are elves in my medicine chest that no one else can see.")
4. Moral statements ("Everyone should vote Republican." "You should be willing to sacrifice your life for others.")
   1. This is sometimes called the "is-ought" dichotomy. . .
   2. Science can explain why the world is the way it is, and predict what will happen if you do certain things. . . but there is no logical way for it to tell you what you should do.
   3. The naturalistic fallacy is the logical mistake of asserting that something that is is something that should be. (Your professor is extremely nearsighted, but that doesn't mean that he shouldn't wear glasses. Some people are very aggressive, but that doesn't mean that they should kill other people if they want to.)
5. Supernatural and religious ideas ("The universe was created by the god Odhinn, and his brothers Vili and Ve, from the dismembered body parts of the corpse of the giant Ymir.")
   1. Scientists work with what we think of as natural forces and phenomena -- matter, energy, space, time.
   2. The "supernatural", whether it exists or not, is probably impossible to test. (And if it was testable, would it still be supernatural?)
   3. This doesn't mean scientists themselves must be atheists or agnostics -- in fact, religious beliefs of many kinds are fairly widespread among scientists.
   4. And it definitely doesn't mean that scientists don't feel awe and amazement and wonder at the world -- most of them definitely do!
   5. But it means that, in their work, scientists generally don't (or shouldn't) blend science with religion -- at least, not as the two terms are usually understood in our culture.
      • Example discussed in class: the 1999 Kansas City clinical trial of the effectiveness of prayer in recovery from heart attacks. It found a clinical benefit to intercessory prayer. . .
      • . . . but the latest and largest clinical test of intercessory prayer, called Study of the Therapeutic Effects of Intercessory Prayer (STEP), showed no benefits -- coronary bypass surgery patients who were prayed for by outsiders didn't do any better than patients who weren't. (Here's a recent newspaper article on the subject, or check out the official press release.)
      • Serious problems arise when you try to define and measure prayer and its effects. . . as we discussed.

III. Wrap-up on experimental methods

1. Not all fields of science use experiments!
   1. Sometimes experiments aren't possible or aren't practical (e.g. geology, astronomy, meteorology, global climate research).
   2. In other cases, experiments are possible but would be unethical to do (e.g. certain areas of medicine, such as certain kinds of human brain research).
   3. In these fields, careful observation is the norm. We can't eliminate all the variables, but we can note carefully what they are and how they might work.
   4. Model building is another possible appproach -- experiments can be done on a model of something (whether a physical model, a mathematical model, or, more frequently these days, a computer model).
   5. Reasoning like a scientist often involves jumping back and forth between formal experiments, observations, modeling, and hypothesizing.
2. But regardless of how you do science, what you do must be reproducible.
   1. Anyone should be able to follow what you've done and find the same thing you did
   2. The real point of using "scientific jargon" should be to describe precisely. (Though it may not seem that way. . .)
   3. This is what makes science a universal endeavor -- anyone, whether capitalist, Communist, left-wing, right-wing, male, female, atheist, born-again, WHATEVER -- should be able to check an experiment's results, or someone's observations or models, and either confirm them or call them into question.