R help - Sep 2011 - Advice on approach to weighting survey

I'm about to add weights to a bus on-board survey dataset with ~150
variables and ~28,000 records.  My intention is to weight (for each bus
"run") by boarding stop and alighting stop.  I've seen the Rake
function of the Survey package, but it seems that converting to a
"svydesign" might be excessive for my purpose.

My dataset has a huge number of unique "Run-Boarding" and
"Run-Alighting" groups each with a small number of records to expand. 
Would it be easier to manually implement
Iterative-Proportional-Fitting/Raking/Fratar/Furness on the data?  Or are there
benefits to converting the data to a svydesign that would make it valuable? 
This "traditional" weighting expands what we call unlinked (based on
each boarding)trips.  I'm thinking of also using IPF/Raking to estimate
linked (based on each individual) trips.  Would this change the consideration of
using the svydesign process?



I initially looked into this process about 3 years ago, but haven't touched
R since then....




Thanks in advance,



Robert Farley
LACMTA
1 Gateway Plaza
Los Angeles, CA 90012-2952
(213)922-2532


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On Sat, Oct 1, 2011 at 4:59 AM, Farley, Robert <FarleyR at metro.net>
wrote:
> I'm about to add weights to a bus on-board survey dataset with ~150
variables and ~28,000 records. ?My intention is to weight (for each bus
"run") by boarding stop and alighting stop. ?I've seen the Rake
function of the Survey package, but it seems that converting to a
"svydesign" might be excessive for my purpose.
>
> My dataset has a huge number of unique "Run-Boarding" and
"Run-Alighting" groups each with a small number of records to expand.
?Would it be easier to manually implement
Iterative-Proportional-Fitting/Raking/Fratar/Furness on the data? ?Or are there
benefits to converting the data to a svydesign that would make it valuable?
?This "traditional" weighting expands what we call unlinked (based on
each boarding)trips. ?I'm thinking of also using IPF/Raking to estimate
linked (based on each individual) trips. ?Would this change the consideration of
using the svydesign process?
>
If you're planning to do any analysis afterwards it would be useful to
have the data in a svydesign object, or if you end up needing to do
weight trimming or bounding, or other slightly more complicated weight
adjustments.  Otherwise it might well just be easier to do your own
IPF algorithm.

   -thomas

-- 
Thomas Lumley
Professor of Biostatistics
University of Auckland