Statistics out of context mean nothing, statistics only mean something in a contextual presentation or shown as a matter of change. Here is what I mean.
While I can't find it on the net, there is a puff piece about Lancaster on the Home Center section of the May 20 DMN. Routinely the paper spotlights a community and lately has done so with a picture of a couple by the article with their home, ususally re done, and a positive statement about the community. And routinely the paper prints 'crime statistics.' Here is the stat on Lancaster
2006 Crime one murder, eight rapes, 17 robberies, 141 aggravated assauts, 880 burglaries, 224 vehicle thefts and 505 thefts
To which my wife exclaimed, that's terrible, to which I said,. how do you know? My point is that citing this as a statistic is utterly meaningless. Here is why
There is no baseline for reference. What should be the average or above average stat for a bedroom community of 34,000 on the edge of a large metro area-five murders, 200 aggravated assaults, what? Here we have no idea as the article does not reference any baseline that we can use, ie what is normal, what should we expect
Next, what is the trend? This is my personal gripe about most statistics. The Odessa Realtors in their monthly meeting used to cite the numbers of homes listed or sold or whatever for the month. So what, that tells me nothing! Is the trend rising, falling, flat, what? This is why graphical presentations are so effective. A bar or line graph tells one quickly in this case whether crime is up down or the same.
I asked my wife why she was alarmed. Well she replied, the numbers were much better for San Marcos, Really, what were they I inquired? She did not know but she felt they were lower. YIKES this is exactly what real statistics are trying to filter out, get past the feelings and let's see the facts.
My point to students is that stats are only meaningful in context. Citing a stand alone statistic tells the reader or listener nothing about what is actually happening. So, learn to use the graph function in excel and present your statistics in context!
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nterested? Learn more by reading Lies Damned Lies and Statistics. I ran across this book while researching my dissert, and it really makes some good points about how someone wanting to emphasize his or her cause often skews or distorts the facts.