Screener form mailing Standard packet (no logo) Logo/insert Participation rate
Mailing 1 enclosures 7,274 No experiment at mailing 1 780*
10.7%**
 Cover letter
 FAQ
 Screener form
 $2 incentive
 Business reply envelope
Postcard – Reminder cards sent to all sampled addresses
Mailing 2 enclosures 3,260 3,253 425
6.8%
(Experimental mailing 1)
 Cover letter
 FAQ
 Screener form
 Business reply envelope
Mailing 3 enclosures 2,883 2,893 342
6.0%
(Experimental packet 2)
Note: Packet enclosed in USPS priority
 Mail envelope
  Cover letter
  FAQ
  Screener form
 Business reply envelope