topic Sampling Question in SAS Procedures

Sampling Question

Habs4Life — Thu, 22 Mar 2012 19:03:20 GMT

proc surveyselect data=SORTMARCH2012DATA

method=srs n=2

seed=1979 out=MarchTrackingIDSample;

strata TrackingIDLength;

run;

I have a table of barcode scans. I am analysing the length of the barcodes scanned. The code above gives me 2 random samples for each Barcode length in the data. I would like to have 5 random samples for each Barcode length (where possible), however cannot make n=5 because there are only 2 instances of some Barcode lengths(resulting in a script failure). Does anyone know how to get around this limitation?

Thanks for your time,

James

Re: Sampling Question

PGStats — Thu, 22 Mar 2012 20:32:50 GMT

I think this would work :

proc sql;
create table strataSampleSizes as
select TrackingIDLength, min(count(*), 5) as _NSIZE_ from SORTMARCH2012DATA
group by TrackingIDLength;

proc surveyselect data=SORTMARCH2012DATA
         method=srs N=strataSampleSizes
         seed=1979 out=MarchTrackingIDSample;
      strata TrackingIDLength;
   run;

PG Corrected the code.

Sampling Question

ballardw — Thu, 22 Mar 2012 21:04:55 GMT

Since you are using a STRATA statement you have the option of using SAMPSIZE in the proc statement.

such as SAMPSIZE = (5 5 5 2 5 5 2 5 5)

The samplesize is then PER strata corresponding to the sorted order of the strata. In my exampe the 4th and 7th Strata are the ones that only have 2 samples.