jcp-data-analysis

Data Analysis (jcp-data-analysis)

When to trigger

• Your effect is significant but the process evidence does not yet hold up
• You ran mediation but a reviewer calls it correlational or under-powered
• A moderation is predicted but the interaction is messy or the simple effects are not probed
• You need to report results to JCP's post-rigor-reform standards (effect sizes, CIs, exclusions)
• The measure of your psychological process is noisy or its validity is in question

Analyze the process, not just the p-value

JCP's contribution is a mechanism, so the analysis must make the process visible and defensible. The headline test of the effect (typically ANOVA or regression with the manipulated IV) is necessary but not sufficient; the paper lives or dies on whether the mediation/moderation evidence supports the proposed psychological process and rules out rivals. Report estimates with effect sizes and confidence intervals, exact statistics, and full Ns before and after pre-specified exclusions. APA reporting style is the house norm.

The analysis toolkit by link in the chain

Link	Standard analysis	What reviewers look for
Existence of effect	t-test / ANOVA / OLS with the manipulated IV	clean cells, effect size (d, η²), CI, no covariate fishing
Measured mediation	bootstrapped indirect effect (e.g., PROCESS / lavaan), bias-corrected CI	indirect effect with CI excluding 0; honesty that this is correlational evidence on the mediator
Experimental mediation	causal-chain design or manipulated-mediator analysis	the manipulation of M moves Y as the theory predicts
Moderation	regression interaction; ANOVA factorial	interaction term + probed simple effects (spotlight/floodlight), not just a significant interaction
Moderated mediation	conditional indirect effects (index of moderated mediation)	the index, with CI, and conditional indirect effects by moderator level

Prefer experimental/causal-chain mediation and moderation-of-process over measured-mediator-only inference: JCP reviewers now treat a bootstrapped indirect effect on a self-reported mediator as suggestive, not dispositive, because it cannot establish the causal direction of M → Y.

Measuring the psychological process

• Validate the mediator measure: report reliability (α/ω) for multi-item scales; show the measure captures the intended construct and discriminates from confounds (mood, arousal, difficulty).
• Rule out alternative mediators statistically: include rival process measures and show the focal mediator carries the effect when they are modeled together.
• Avoid mediator-as-manipulation-check confusion: a manipulation check is not a mediator; the mediator is the downstream mental state.

Rigor-era reporting (post-2010s consumer-psych reforms)

• Report exact test statistics, p-values, effect sizes, and CIs — not just "p < .05."
• Disclose all conditions and measures collected; do not hide arms (the disclosure norm).
• Report sample size determination and adherence to (or deviation from) the pre-registration.
• State exclusions and their rule transparently, with Ns before/after.
• Avoid asterisk-only tables; report the numbers a reader needs to assess the process.

Checklist

• Effect reported with exact stats, effect size, and CI; cells and Ns clear
• Mediation uses bootstrapped/bias-corrected CIs; measured-only mediation is labeled correlational
• At least one stronger-than-Baron-Kenny process test where the claim is causal
• Moderation: interaction reported and simple effects probed (spotlight/floodlight)
• Moderated mediation: index of moderated mediation + conditional indirect effects
• Mediator measure reliability reported; rival mediators modeled and ruled out
• Exclusions pre-specified; all conditions/measures disclosed; preregistration deviations noted

Anti-patterns

• Indirect-effect worship: a significant bootstrapped indirect effect treated as proof of causal process
• Interaction without simple effects: a significant interaction with no spotlight/floodlight probing
• Covariate fishing: adding controls until the effect appears, undisclosed
• Hidden arms: dropping conditions or DVs that didn't work without reporting them
• p-only reporting: asterisks instead of effect sizes and CIs
• Mediator confound: a "mediator" that is just mood/difficulty the manipulation also moved

Output format

【Effect】test, stat, effect size, CI, cell Ns
【Mediation】measured / experimental; indirect effect + CI; correlational caveat if measured-only
【Moderation】interaction + probed simple effects (spotlight/floodlight)
【Moderated mediation】index + conditional indirect effects (if applicable)
【Process measure】reliability + rival mediators ruled out
【Rigor disclosures】exclusions, all conditions/measures, preregistration deviations
【Next skill】jcp-contribution-framing