Scientists should be dispassionate observers, not letting their personal beliefs prevent them from seeing facts as they are.
Consider the story of two scientists from the early twentieth century. One was American, the other Austrian. One faithfully recorded every measurement that he made, and included them all in his calculations, with no personal bias. One discarded those that were wildly at variance with his theory, and gave greater weight to those that he thought were his “best” measurements. One was right, and the other was wrong.
As you’ve probably guessed, the one who was right was the one who was selective in his choice of data. He was American, and his name was Robert Millikan – a name that is now forever associated with the first accurate measurement of the charge on the electron. He did it using his famous “oil drop” experiment, and his notebooks are littered with notes such “e=4.68, which means this can’t have been an oil drop [it was probably a particle of dust]”.
The one who was wrong (the Austrian) was called Felix Ehrenhaft, whom few people now remember. He included every measurement without fear of favour, and as a result got the answer wrong by a factor of around 300. Statisticians call it overfitting – fitting to the noise rather than the signal, and so missing the true underlying pattern.
But how can you tell what is noise, and what is signal, in a set of observations? That’s where judgment can come in .
Still think that science should be dispassionate and objective, with no personal element? Maybe it’s time to think again.
You can find the whole Millikan/Ehrenhaft story in my book Weighing the Soul.