Hello, I "inherited" the reporting system for our escapes and have some
questions about how data has been reported in the past.
First, I have a question about the formula used to calculate escape rates
which is (escapes)/(average daily population - escapes). Then this is
reported as a rate per 100 inmates. Isn't this actually a ratio of escapees
to non-escapees. Maybe I'm just picking at semantics, let me know. I
thought that the formula for rates was (a/(a+b)) * k where the numerator is
included in the denominator.
Then I also have a rule of thumb question. At what point is a rate
considered unreliable or a useless piece of information? My example again
and remember that it uses the "formula" I first presented above. The
previous reports show rates of .44 per 100 or .08 per 100, etc. Of course I
find this comical because I imagine that .44 means an escapee with only a
torso, legs and head and .08 as an escapee with only the torso! But, many
folks around here take those numbers to indicate that the escape "rate" has
decreased substantially! I have seen CDC tables with a caveat regarding
small rates and will pull those as evidence for my argument.
So here's a real life problem for my colleagues out there. I am going
through all the statistics books in my office and have started to search for
references to present my case. I'm not kidding because I was told that this
is the way it has always been calculated so don't mess with tradition. If
anyone has any references, suggestions, openings for positions, cites to
search, etc. I would really appreciate it. Many thanks in advance, Fran
Fran Ferrari, Researcher
Data Analysis & Statistics
Oklahoma Dept. of Corrections
50 NW 23rd Street
Oklahoma City, OK 73105
PH: 405-522-4964
FX: 405-522-4961
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