Sunday, December 5, 2010
Amateur Data Gathering
If I tell you that I've been having gastrointestinal trouble, since I started consuming Splenda itself and products that use Splenda, you would rightly say that the evidence of a connection is just anecdotal. That term is used to dismiss a lot of data gathered by amateurs, Actually, when accurately reported, I prefer anecdotal evidence to statistical evidence, just as I prefer in-depth interviews with likely voters to telephone surveys. The conclusions of a statistical study carried out at a university or health organization often turns out to be misleading or just plain wrong, because of the risks inherent in the design of population studies.
Continuing on with my "Slenda" story; I went to the web to see what I could find. Lo and behold, there was a forum which contained many first hand accounts of gastric distress accompanying the use of Splenda and a few that said complainers were all crazy. The first defect in such forums is that it automatically selects people that are in distress. If I started a forum for people who have experienced sneezing fits after turning on their computers less than an hour after eating, there would immediately be 50 contributions from people who had that experience. It's just the statistical nature of the huge number of people browsing the internet. However, I'm not quick to dismiss honest data. Outliers can contain important information. Every experiment deserves to be explained.
My question for this blog is this. Astronomers have used thousands of amateurs to scan the skies that are too vast for professionals to monitor. Can the anecdotes of amateurs be filtered and combined in such a way as to produce valid scientific evidence? If one hundred people who report stomach distress stopping after quitting Splenda, are asked to restart in order to see if the distress starts again, can we draw any conclusions. How many times must we reproduce the start-stop cycle with each of these amateurs before we can have some confidence in the results?