Precision and Accuracy
I may have written an essay about this topic before, but you know, I think it bears revisiting. For one thing, every time I write about something, I am coming back to it with deeper understanding, more experience, and a changed outlook. I can't help it, really. Time is not static, therefore neither am I. I change, and the world changes around me. I cannot return precisely to the same point each time.
Which is precisely my point. Most of my life I'd treated precision and accuracy as different words for the same meaning. It took my patient Analytical Chemistry professor some time to pound through my thick skull that in science, they are not the same. Precision is the quality of a test that enables it to return the same results over and over. In this, 2+2 will always equal 5. Test it again, get the same answer. That's a precise test. But wait, you say, that's not the right answer. Which is why you also have to have accuracy. An accurate result is one that is closest to the truth - that is, to the actual answer. So in an accurate test, you'd have something more like 2+2=4.1, or 3.9, or 3.9999999... you get the idea. In an ideal world, you want both precise, and accurate.
So how do you know what truth is? If you have a test for truth that is precise, you might well believe that twice two is indeed five. Perhaps that is too simplistic. Or perhaps not. We once believed, after all, that we only used 10% of our brains. That hair and fingernails continued to grow after death. That drinking urine was a valid medical practice. Something that may seem obviously false to us might seem obviously true to someone else. Which is why we have to constantly question the answers we are presented with, to return to my essay earlier this week on the human drive for answers.
So this is why we have the scientific method. Because if we are working from the platform of an erroneous hypothesis, in theory using observations, experiments, and testing will show us that two objects, added to another two objects, yields a total of four objects, negating our former hypothesis of the total being five objects. And again, this is a method that does have limitations. How are you going to measure, exactly, the mass of a, say, galaxy? How are you going to prove or disprove the existence of a soul? Karl Popper in his Logic of Scientific Discovery proposed that in order to be science, it must be falsifiable - in other words, you must be able to prove it true, or not-true. Souls are not provably truth. Which is not to say they do not exist - I firmly believe I have got one. However, there is no test which can state accurately that I have got one. Souls, in short, are not the province of science, but of faith.
Popper also pointed out the philosophical problem is cosmology, the "problem of understanding the world—including ourselves, and our knowledge, as part of the world." If we play with the meaning of words, here, as I think we can given his interest in linguistics, we can say that a soul is not part of the world. So science is limited to this world. Souls are not so bounded. As a scientist, I am not attempting to study otherworldly phenomenon, except to perhaps prove them worldly, in truth. I shall, then, trouble myself no more about my soul. It is there, that is enough, and I shall turn my mind into other channels, as I attempt to do what Popper proposes as an ideal of science "we ought to try as hard as we can to overthrow our solution, rather than defend it."
If, then, we have a test we believe to be returning a true value because it returns the same answer over and over, is it insanity to question that test's results as being rather more precise than accurate? In the laboratory, I use controls, standards, and calibration to ensure that my results fall within known, measurable, and quantifiable marks. Like shooting at a bullseye. If you fire at a blank piece of paper, and can see a mark on it, you have hit the target. Quite good! Bravo you! But how well did you do? You hit the paper, yes, which is better than not hitting it at all. But this is not a very precise test at all. Let us print a series of concentric rings on the paper, and then we shall know - did we hit what we were aiming at, given that our aim was toward the smallest central mark on the paper? our controls and standards, our blinds, in a medical study, are in science are akin to painting the bullseye on the paper. It gives us measurable, quantifiable ways to make the results make sense in our cosmos. If we cannot have those, the results are meaningless, no matter how many times we can generate the same result. And as for calibration, well, the results are only as good as the instrument generating them. If our rifle we are aiming at the bullseye has a bend in the barrel, will we be precise, or accurate? Might as well use a shotgun and call the myriad of holes answers. All over the map, and meaningless. Noise, in other words, when we speak of statistics.
We are no closer, are we, to defining truth than when I began? We can see, I hope, that precision is not always truthful, and therefore is sometimes inaccurate and undesirable. Pursuing the truth is not an unworthy goal, nor is it one I can encompass in a simple essay. Coming back to Popper and his introduction to the logic of science, we see that he wanted this pursuit to be one more people took part in. "Only a revival of interest in these riddles can save the sciences and philosophy from narrow specialization and from an obscurantist faith in the expert’s special skill, and in his personal knowledge and authority; a faith that so well fits our ‘post-rationalist’ and ‘post-critical’ age, proudly dedicated to the destruction of the tradition of rational philosophy, and of rational thought itself."
Ask questions, then. You don't have to be a 'scientist' with a PhD or an academic in an ivory tower, to puzzle out the riddles of the cosmos. The world is all around you. Observe it, test it, and experiment with the answers that are given to you as 'settled science' because not all answers are accurate ones.