The Spacetime Metric

Level 3 · Undergraduate core teaching kit · First- and second-year university

Experimental design, inference, and reproducibility

Use the learner record during the live investigation, then use the instructor guide to facilitate comparison, address misconceptions, and assess evidence-bounded reasoning.

Learner lab record

Blinded residual and search-penalty analysis

When does a local residual remain credible after correlated uncertainty, injection recovery, and the declared search space are included?

Setup

Use the blinded-analysis laboratory. Freeze the model and cuts, inspect a baseline null ensemble, then test one hidden injection and apply the declared search adjustment.

Predict first

  1. 1. Predict whether more trials remove a fully correlated offset.
  2. 2. Predict how a larger declared search count changes global significance.
Variables
VariableRoleUnit
Trial count and independent noisedesign inputscount and signal unit
Correlated systematicshared uncertainty inputsignal unit
Injected signalvalidation inputsignal unit
Local and adjusted significancedependent diagnosticsσ or probability

Observation columns

trialsindependent σcorrelated σinjectionrecovered?local resultadjusted result

Analyze

  1. 1. Which uncertainty term averages down?
  2. 2. Did the pipeline recover the known injection within tolerance?
  3. 3. Why can a local detection become a global non-detection?
  4. 4. What decision must be frozen before unblinding?

Conclusion frame

The pipeline produced local ___ and adjusted ___ across ___ searches; injection recovery was ___, so the preregistered decision is ___.

Instructor guide · 55–75 minutes

Teach the investigation, not the interface

Learning target: Learners treat blinding, correlated uncertainty, injection recovery, and multiplicity correction as one evidence pipeline rather than optional post hoc cautions.

Prepare

  • Define the analysis decision before revealing the modeled result.
  • Prepare one failed-injection case.
  • Distinguish local from family-wise probability.

Facilitation moves

  • Ask which choices were made before unblinding.
  • Do not allow trial count to erase shared systematics.
  • Require a decision statement even for an interesting residual.

Accessibility and participation

  • Translate probabilities into frequencies without overstating certainty.
  • Provide the decision tree in text and diagram form.
  • Allow spreadsheet or calculator support for uncertainty combination.

Evidence of learning

  • A frozen analysis decision
  • A correct correlated-error explanation
  • An injection and multiplicity-aware conclusion

Misconception checks

Enough repeated trials eliminate every uncertainty.

Independent noise averages down; correlated bias and model error require separate controls or bounds.

A small local p-value proves the preferred mechanism.

Search multiplicity changes surprise, and mechanism attribution requires discriminating predictions and controls.

Extension

Design a preregistered two-laboratory replication with a shared injection protocol and independent analysis teams.