<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=iso-8859-1" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 8.00.6001.18854"></HEAD>
<BODY>
<DIV><FONT size=2>
<DIV><SPAN class=859451414-23112009><FONT size=2>I'm compiling some comparisons
of 2006-08 ACS and 2000 Census data, and I'm looking for some guidance in
estimating standard errors for 2000 CTPP tables. For the place of residence
data, I have applied the estimation procedures outlined in the 2000 SF3
documentation:</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2> Unadjusted
standard error:</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009>
<FONT size=2>SE(Y) = sqrt(5*Y*(1-Y/N)),</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2> where N =
size of publication area (total population)</FONT></SPAN><SPAN
class=859451414-23112009><FONT size=2> and Y = estimate of characteristic
total</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2>This value is then multiplied
by a design factor determined by the state, sample rate and
characteristic.</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2>Are these methods also
applicable to the workplace (CTPP part 2) tables? If so, what assumptions can I
make about sample rates, and are the standard error design factors applicable to
place of work statistics?</FONT></SPAN></DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=859451414-23112009><FONT size=2>Any advice will be greatly
appreciated.</FONT></SPAN></DIV></FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT
size=2>----------------------------------------------------</FONT></DIV>
<DIV><FONT size=2>Paul Reim</FONT></DIV>
<DIV><FONT size=2>Chief Planner, Data Resources</FONT></DIV>
<DIV><FONT size=2>Central Transportation Planning Staff</FONT></DIV>
<DIV><FONT size=2>Boston Metropolitan Planning Organization</FONT></DIV>
<DIV><FONT size=2>10 Park Plaza, Suite 2150</FONT></DIV>
<DIV><FONT size=2>Boston, MA 02116-3968</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Phone: (617) 973-8132</FONT></DIV>
<DIV><FONT size=2>Fax: (617) 973-8855</FONT></DIV>
<DIV> </DIV></BODY></HTML>