Good Scientific Method?

Quite properly scientific method insists on clearing the decks of all preconceptions and contaminations before an experiment is begun. You begin with a tabula rasa and put your results on it. Unfortunately when dealing with ourselves, the scientists, it is not possible to clear the decks in this way as we are already there. If we truly clear the decks there'll be no one left to do the experiment! Instead we have to notice or not ignore what is there and take it into account. Not to do so is, well, bad science. Studying human behaviour is, therefore, an imprecise art involving forms of mental contortion; the problem of psychology, political pollsters and economic forecasters. Some have suggested that literature 'captures' the human more accurately than the data method.