Methodology
Full transparency in how we design, conduct, and report our research. Every methodological choice has a cited rationale.
Survey Design Overview
PIIR's quarterly survey follows a rigorous design process rooted in established survey research methods. Our approach prioritizes consistency, representativeness, and comparability with international research programs.
Sampling Framework
Multi-stage probability sampling ensures every Filipino has a known, non-zero probability of selection.
Stage 1: Stratification
The Philippines is divided into primary strata based on the three island groups (Luzon, Visayas, Mindanao) with the National Capital Region (NCR) treated as a separate stratum. Within each stratum, primary sampling units (PSUs) are provinces or highly urbanized cities.
Stage 2: Cluster Selection
Within selected PSUs, barangays are randomly selected with probability proportional to size (PPS). This ensures that more populous barangays have a proportionally higher chance of selection, maintaining representativeness.
Stage 3: Household Selection
Within selected barangays, households are selected using systematic random sampling from updated household lists. A Kish grid or equivalent random selection method is used to select one eligible respondent per household.
Weighting
Survey data is weighted to match known population parameters from the most recent PSA population estimates. Weights adjust for selection probability, non-response, and demographic distribution (age, sex, urban/rural, region). Post-stratification weights ensure the final sample reflects the Philippine population.
Data Collection
Field Operations
PIIR uses a university partnership model for field surveyor recruitment and training. Research assistants from partner universities conduct face-to-face interviews using tablet-based questionnaires.
- Standardized interviewer training protocol
- Real-time data quality monitoring
- GPS verification of interview locations
- Audio recording with respondent consent
- Supervisor back-checks on 10% of interviews
Tools and Technology
Open-source tools ensure transparency and replicability. All analysis code is published alongside results.
Quality Control
Multiple layers of quality assurance from questionnaire design through final publication.
Pre-Field
- Cognitive testing of questionnaire
- Pilot survey with debriefing
- Expert review of question wording
- Back-translation verification
During Field
- Real-time data monitoring dashboard
- Automated logic and consistency checks
- GPS and timestamp verification
- Supervisor call-backs and spot checks
Post-Field
- Data cleaning and outlier detection
- Response pattern analysis
- Cross-tabulation consistency checks
- External expert review before publication
Publication
- Full methodology disclosure in every report
- Response rate calculation (AAPOR standard)
- Confidence intervals on all estimates
- Limitations section in every publication
Transparency Commitments
PIIR follows the AAPOR Transparency Initiative standards. Every published report includes the following disclosures.
Academic Citation and Registration
ISSN Registration
The PIIR Quarterly Report will be registered as a serial publication with an International Standard Serial Number (ISSN). This enables formal academic citation and library cataloging, ensuring PIIR data is discoverable through standard academic databases and indexing services.
Report Structure
All published reports follow academic publication standards: abstract, methodology, findings, discussion, limitations, and appendices. External data citations use standard academic referencing. Clear distinction is maintained between PIIR primary data and secondary/government data.
Research Partnerships
PIIR pursues formal research partnerships with Philippine universities and international research networks. Application for membership in the World Association for Public Opinion Research (WAPOR) is planned following the publication of Wave 1 results.
Questions About Our Methodology?
We welcome methodological inquiries and peer review. Transparency is fundamental to our mission.