The data presented on this website were
obtained from a wide range of credible sources including the U.S.
Census Bureau, Florida Department of Education, Florida Charts, a
product of the Florida Department of Health, and numerous other
federal, state and county sources. For the most part, data from
sources other than the U.S. Census Bureau are based on actual
counts.
Data available from the 2000 decennial
Census contain 100% population and housing counts (Summary File 1)
and sample data based on a one-in-six sample (Summary File 3). Data
contained in the 2001-2008 annual American Community Surveys are
based on a very small sample of U.S. Households and contain both
sampling error and nonsampling error. According to the Census
Bureau:
Sampling errors are "errors that occur because only part of
the population is directly contacted. With any sample,
differences are likely to exist between the characteristics of
the sampled population and the larger group from which the
sample was chosen. Sampling error, unlike nonsampling error, is
measurable."
Nonsampling errors are "errors that occur during the
measuring or data collection process. Nonsampling errors can
yield biased results when most of the errors distort the results
in the same direction. Unfortunately, the full extent of
nonsampling error is unknown. Decennial censuses traditionally
have experienced nonsampling errors, most notable undercount,
resulting from people being missed in the enumeration
processes."
A detailed description of the sample
design and methodology for the 2000 Census and the American
Community Survey can be found on the Census Bureau’s websites:
Since the American Community Survey data
are based on very small samples, the data may contain significant
margins of error. Please take this into consideration when reviewing
or using the data presented on this website. Data for three-year
estimates will have a smaller margin of error than data for a single
year. The sample sizes for Pinellas and selected Florida counties
for each survey year are shown in the table below and represent
approximately 1.2% of the total housing units in each county.
Year
Pinellas
Duval
Hillsborough
Orange
Palm Beach
2001
1,619
1,224
1,624
1,380
2,139
2002
1,487
1,113
1,476
1,284
1,961
2003
1,840
1,286
1,694
1,443
2,203
2004
1,843
1,234
1,679
1,474
2,228
2005
6,365
4,278
6,184
5,221
8,027
2006
6,343
4,487
6,432
5,411
8,236
2007
6,166
4,475
6,323
5,318
8,067
2008
6,067
4,583
6,262
5,463
8,087
Definition of Terms
Margin of Error (MOE)
The margin of error is the difference
between an estimate and its upper or lower confidence bounds.
Confidence bounds can be created by adding the margin of error to
the estimate (for an upper bound) and subtracting the margin of
error from the estimate (for a lower bound). All published margins
of error for the American Community Survey are based on a 90 percent
confidence level.
