study_title: How Many Sites Cheat PageSpeed? A Dual-Profile Census of Lighthouse/PSI
  Cloaking
registered_on: YYYY-MM-DD before crawl
primary_estimand: Site-level confirmed PageSpeed cloaking prevalence among the fixed
  top-sites sampling frame.
secondary_estimands:
- Upper-bound suspicious prevalence
- Technique-specific prevalence
- Prevalence by platform/CMS
- Prevalence by country of crawl egress and primary-market country
- Prevalence by rank band and sector
primary_sampling_frame:
  recommended: Fixed Tranco list ID/date, stratified by rank band
  alternative: CrUX origins for field-data coverage sensitivity
  unit: registrable domain or canonical origin; declare and do not mix
profiles:
- 'REAL_CHROME: current stable Chrome, human-like mobile/desktop viewport, normal
  UA-CH, warm/cold cache sequence'
- 'LH_PSI_EMU: version-locked Lighthouse/PSI-like mobile profile with declared UA,
  UA-CH, viewport, throttling, platform, and environment'
- 'ABLATIONS: hold all constant while varying one fingerprint vector at a time'
replicates:
  paired_runs_per_profile: 3
  order: randomized ABBA/BAAB blocks
  countries_minimum:
  - US
  - DE
  - BR
  - IN
  time_windows: spread across 3 days; preserve UTC time
positive_rule: Confirmed positive requires direction, stability, specificity, and
  materiality criteria.
statistical_models:
- Weighted binomial prevalence with bootstrap confidence intervals
- False-positive adjusted Rogan-Gladen estimator using manual validation sensitivity/specificity
- Bayesian hierarchical logistic regression for platform/country/rank effects
- Sensitivity analysis across thresholds and exclusion rules
public_release:
  release_immediately:
  - codebook
  - sampling manifest
  - feature matrix
  - hashes
  - aggregate tables
  embargo:
  - raw suspected site URLs and raw artifacts for disclosure window
  never_release:
  - credentials, login-only content, personal data, full copyrighted page copies unless
    licensed
