OK, so you know that I am opinionated and you can read the title to this post. I am also aware that there are a whole lot of people out there in genealogy land who love fan charts. There are even some of my friends that make a living designing and printing fan charts and other family charts. I tolerate these printed charts but I am not a fan. I certainly do not wish to offend any of these people, nor do I wish to disuade anyone from making a chart of their family. If it works for you, do it.
The fundamental reason I have problems with fan charts is not really very simple. It has to do with the tentative nature of genealogical research. Past a certain point all entries in my family file are liable to be revised with further information. Printing out a chart, even for decorative purposes, codifies the entries. It makes people think that the information is "etched in stone" and cannot be changed.
But, you say, I can use a fan chart to easily identify those areas in my family that need research. Hmm. The problem is that the fan chart makes you look at the holes, not at the incorrect information that may be lurking just below the empty entries. There is an unspoken inference that the information you find to create your fan chart is correct. That may or may not be the case. But those who print out fan charts automatically start looking in the blank spaces and, for the most part, in my experience, ignore the information they already have in their file.
But aren't they pretty? Don't they help give you a graphic idea of how your family is organized and who you are related to? Aren't they impressive at family reunions? Yes, to all of those questions, but fan charts have been around for a very long time and so have 12 generation pedigree charts and I haven't been enticed to use either. There is something about printing out a "final" copy of your research that makes it seem final. Would you reprint a new fan chart every time you made a change to your information? I think not. So who is going to use the fan chart and who is going to rely on it?
Just like surname books that keep repeating the errors of the genealogical past, fan charts become a transmitted preservation of errors. Once it is on the wall or on paper at all, it is now a formal document and becomes the authority for the rest of the family. So how do I go about changing my relative's printed fan chart when I find a whole new line or correct a whole new line? How many fan charts have you seen where the information on the chart was not completely accurate?
But, you say, you are being an old fuddy-duddy and need to get a life. What harm is there in making a fun chart for your family? Maybe, just maybe, the budding genealogist in your family will be motivated by the chart to dig into the records and do some real research? Again, I am not inclined to disuade anyone from making any kind of chart they like, I just don't think they work for me.