It usually starts with the smallest of things, and starts rather "innocently" at that.
Remember when you are in the laboratory conducting an experiment, say titration between an acid and a base. You collect the data required until the pH indicator used, for instance, phenolphthalein changes colour. You tabulate the data and try to plot a graph from the data. The theory says that you should get a perfect straight line for the neutralisation process. However, the data you collected does not even give a hint of a straight line.
What should you do, what should you do? You need the straight line in order to get marks for your laboratory assignment. A curve wouldn't do. A zig-zag is definitely out of the question. There is only one thing to do. Adjust the data that you collected so that you will be able to draw the best straight line.
This scenario is perhaps familiar to some of us who have done laboratory work before (in particular during the undergraduate years). Changing the data so that the result would match the theory taught seems to be the best solution. But is it?
Often, researchers forget that an experiment should be repeated in order to get the best results. Experiments are proned to errors either human errors or apparatus errors. [Trivia: It was al-Biruni who suggested that experiments must be repeated to minimise errors]. However, most (especially during the undergraduate years) would opt for the short cut since most know what the result should be anyway. This is in fact a folly made by many. The point of a laboratory experience is to instill patience, perseverence and integrity. If you get it wrong the first time, then repeat and do it again. Of course, many would dismiss the idea by saying that they don't have much time to complete the experiment and that they have other assignments to do.
Whether one realises its importance or not, integrity must be inculcated from the very first day a person is trained to be a researcher.