The document discusses routing and two types of router approaches - serial and parallel. In serial routing, respondents are screened sequentially for available studies one by one until qualification. In parallel routing, respondents are screened simultaneously for multiple studies via a page of questions and then assigned to a qualifying study. The document also discusses using randomization versus prioritization strategies when determining which studies to screen respondents for in a router.

1. What is Routing?
1ARF FOQ 2 – Router Team Findings

2. “Traditional” Non-router Approach
2
Non-router
…and so on for each individual study
Screener: Study A
Completes
Study A
Draw Sample: Study A
Thank & Terminate Respondent
Outcome:
Qualified
Outcome:
Does Not Qualified
Study A
Not Administered
Invitation: Study A
Screener: Study B
Completes
Study B
Draw Sample: Study B
Thank & Terminate Respondent
Outcome:
Qualified
Outcome:
Does Not Qualified
Study B
Not Administered
Invitation: Study B
Screener: Study C
Completes
Study C
Draw Sample: Study C
Thank & Terminate Respondent
Outcome:
Qualified
Outcome:
Does Not Qualified
Study C
Not Administered
Invitation: Study C
ARF FOQ 2 – Router Team Findings

3. Generic Routing Approach
3
Generic routing
Study A
Study B
Study CStudy D
Study E
Create Sample Frame: To meet needs of studies in routing environment
Invitation: To a central area using multiple methods
Screen: For one or more studies on the router
Assign Study: To a respondent who is qualified, based on screening
Two types of routers exist
in the marketplace…
ARF FOQ 2 – Router Team Findings

4. Serial Router
Definition:
In its most basic form, serial routing is a process whereby a respondent is
screened sequentially for the available studies on a router. Upon qualification
for a study, the respondent is immediately sent into the full survey. Upon
disqualification in any screener, another screener is served to the respondent –
with the process repeating until qualification occurs.
Example
Respondent enters a router, and is randomly served the screener for Study 42.
He does not qualify and attempts Study 23, resulting in another disqualification.
The router then randomly serves the screener for Study 71, the respondent
meets the criteria, and is sent into Study 71 for a full and joyfully robust survey
experience.
4ARF FOQ 2 – Router Team Findings

5. Serial Router
» Visual
5
Router Entry
Screener 42
Outcome: DQ
Screener 23
Outcome: DQ
Screener 71
Outcome:
QUALIFIED
Study 42 Study 23 Study 71
R A N D O M A S S I G N M E N T O F S C R E E N E R S
Screener 8
Outcome:
None
Study 8
ARF FOQ 2 – Router Team Findings

6. Parallel Router
Definition:
In its most basic form, parallel routing is a process whereby a respondent is
exposed to a set of screening questions from all or a subset of the surveys on
the router, simultaneously, on the same page. After the respondent answers
these questions, he or she is assigned to one of the studies for which he or she
appears to be qualified.
Example
Respondent enters a router, and a page of questions is presented that
contains the screeners for Study 42, Study 23, Study 71, and Study 8.
The questions were selected at random by the system with presentation order
randomized. After completion of the page qualification is tested, with the
respondent qualifying for only Study 71 and Study 8. Study 71 is randomly
assigned for a full survey experience.
6ARF FOQ 2 – Router Team Findings

7. Parallel Router
» Visual
7
Router Entry
Screener 42
Screener 23
Screener 71
Screener 8
System Tests
for Qualification:
QUALIFIED:
Screener 71
Screener 8
DQ:
Screener 42
Screener 23
Random
Selection of
Study 71
R A N D O M G E N E R A T I O N O F S C R E E N E R P A G E
Study 71
ARF FOQ 2 – Router Team Findings

8. Overview of Sampling Approaches
8
Parallel router
Screener 42
Outcome: DQ
Screener 23
Outcome: DQ
Screener 71
Outcome:
QUALIFIED
Enters and
completes
Study 71
Serial routerNon-router
Screener 42
Screener 23
Screener 71
Screener 8
QUALIFIED:
Screener 71
Screener 8
DQ:
Screener 42
Screener 23
Random Selection of Study 71
Enters and
completes
Study 71
Screener Study 8
Outcome: DQ
Outcome: QUALIFY
Completes
Study 8
DONE; No
study
completed
…and so on for each individual study
ARF FOQ 2 – Router Team Findings

9. Randomization vs. Prioritization
» Both serial and parallel routers employ algorithms to determine
which study screeners to present to respondents in a router
» Prioritization involves presenting a screener to a respondent
according to predefined business rules, in a non-random
manner
» Common reasons for prioritizing include assistance in
completing lower incidence studies, or a need to finish field
more quickly than current interviewing pace suggests
» In practice, most routers use a combination of random and
priority assignment (e.g., 75% random and 25% priority)
ARF FOQ 2 – Router Team Findings 9

10. Randomization vs. Prioritization
Methods of Applying Prioritization
1. In either routing environment, maintain randomization but
increase the amount or proportion of sample in the routing
environment that is sent to a prioritized study for screening.
2. In a serial routing environment, give a higher priority to displaying
screener qualification questions for a prioritized study.
3. In a parallel router, similarly increase the probability that certain
pre-screening questions will be displayed.
4. In a parallel environment, after determining for which studies a
respondent qualifies, increase the probability of selection of the
prioritized survey (send more people to the study).
ARF FOQ 2 – Router Team Findings 10