The platform is the prompt: data, materials and analysis code for platform-framing effects on AI-generated communication

Open replication package for the study “The platform is the prompt: what survives platform framing in AI-generated communication.” The study treats social-media platforms as part of the prompting environment of large language models. Phase 1 varied twelve platform-framing conditions on one constant question (216 responses across nine models), with coded register qualities assessed by a blind five-rater cross-model reliability check. Phase 2 rendered four controlled fictional dossiers under twelve platform formats (1,051 verified responses across ten models) and applied deterministic measures of form compliance, self-revision and detectable surface retention. The package contains all prompts, conditions, the four dossiers with full item inventories, every model response with raw API metadata, the initial coding and five-rater reliability materials, the deterministic analysis scripts, the original retention-detector check, and a separate blinded four-model cross-panel validation with reliability and weighted precision/recall, verification reports, and the prospective analysis plan. All individuals in the stimuli are fictional; no human or animal participants were involved. The original collection spend before the cross-panel extension was about USD 9.28; provider-reported validation usage and costs are archived in the run provenance.