{"success":true,"window_days":30,"period":{"start":"2026-09-14","end":"2026-10-13"},"last_updated":"2026-10-13T19:15:01+00:00","methodology_version":"1.5.0","minimum_sample_size":30,"integrity":{"snapshot_id":"baba5f6c-2686-4dbd-9337-cefa328216ab","sha256":"931c9455a54c4ffcfdbc64aea450387fa8f3dcb0db156f2641662ccf75c2efe1","source_root_sha256":"23d15d8051e0cb3118dcb0e379e15301a94f2d8c56e63c75f609477971d59fd5","signature_algorithm":"RSA-SHA256","public_key_format":"pem","public_key":"-----BEGIN PUBLIC KEY-----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\nMX6ratE59FfxyWtLu1axYDruy5C5qdJ1ex+KkpYL3XRfAgMBAAE=\n-----END PUBLIC KEY-----\n","key_id":"0b4f666377a73bd402e5c496","signature":"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"},"metrics":{"active_learners":{"status":"not_yet_measured","value":null,"display":null,"numerator":null,"denominator":null,"sample_size":null,"sample_size_label":"Cohort details are withheld until the publication rules are satisfied.","definition":"Unique consented, active verified learner accounts with at least 30 seconds of server-validated audio activity in the reporting period."},"listening_completion":{"status":"not_yet_measured","value":null,"display":null,"numerator":null,"denominator":null,"sample_size":null,"sample_size_label":"Cohort details are withheld until the publication rules are satisfied.","definition":"Eligible learner-lesson records from active verified learner accounts reaching at least 90% genuinely played audio from authenticated, proportional byte-delivery evidence inside the declared 180-day evidence horizon, divided by eligible learner-lesson records active in the selected period; publication requires 30 distinct learners."},"returning_learners":{"status":"not_yet_measured","value":null,"display":null,"numerator":null,"denominator":null,"sample_size":null,"sample_size_label":"Cohort details are withheld until the publication rules are satisfied.","definition":"Active verified learner accounts in the selected period who also had validated activity in the fixed preceding 30 days, divided by active verified learners in the selected period."},"assessment_improvement":{"status":"not_yet_measured","value":null,"display":null,"numerator":null,"denominator":null,"sample_size":null,"sample_size_label":"Cohort details are withheld until the publication rules are satisfied.","definition":"Learner-weighted mean percentage-point change for the full fixed cohort of consented verified learners with a server-issued baseline before listening and a one-time post assessment after genuine 90% completion. Any missing or unverified cohort member keeps the metric Not Yet Measured."}},"supporting":{"quality_audits":{"status":"not_yet_measured","value":null,"display":null,"numerator":0,"denominator":null,"sample_size":0,"sample_size_label":"Sample size: 0","definition":"Distinct lessons with a documented independent audit in the reporting period whose immutable rubric and stored hash still match the current metadata and exact audio bytes."},"exam_verifications":{"status":"not_yet_measured","value":null,"display":null,"numerator":null,"denominator":null,"sample_size":null,"sample_size_label":"Cohort details are withheld until the publication rules are satisfied.","definition":"Distinct consented, active verified learner accounts whose external result evidence was independently verified during the reporting period."}}}