Evidence Grading System
Every protocol on this site carries an evidence grade. This page explains what those grades mean, how they’re assigned, and why they matter.
Definition
The evidence grading system is a four-tier classification (A through D) that communicates how confident you should be in a protocol’s recommendations. It exists because not all advice is equally well-supported, and you deserve to know the difference between “dozens of RCTs confirm this” and “this is an expert’s educated guess.”
Grades reflect the quality, quantity, and consistency of supporting evidence. They do not reflect how useful a protocol might be to you personally.
The Four Grades
Strong (A)
The evidence is robust. Multiple high-quality studies (randomized controlled trials, large cohort studies, systematic reviews) support the core claims. There is broad scientific or professional consensus. Results are replicable across populations. The risk-to-benefit ratio is clearly favorable.
What this means for you: Follow these protocols with high confidence. The science is settled enough that the main variable is your execution, not whether the approach works.
Examples: Sleep optimization, strength training, automated index investing.
Moderate (B)
Good evidence exists but with limitations. Studies may be smaller, less replicated, or mixed in their findings. The mechanism is plausible and the downside risk is low. Professional consensus leans supportive but isn’t unanimous. Some recommendations are extrapolated from adjacent research.
What this means for you: These protocols are well-grounded but leave more room for individual variation. Pay attention to how they work for you specifically and adjust accordingly.
Examples: Ikigai protocol, deep work, hosting gatherings.
Preliminary (C)
Evidence is early-stage: observational studies, expert opinion, emerging research, or extrapolation from related fields. Limited or no RCTs. The approach is plausible but unproven at scale. Explicit cautions are included.
What this means for you: Treat these as informed experiments, not established practices. Monitor results closely. Be prepared to adjust or abandon if the approach isn’t working.
Examples: Information curation.
Speculative (D)
The evidence is thin: anecdotal, theoretical, or drawn from very small studies. Published only with tight labeling and clear exit criteria. These protocols are included because the potential upside is meaningful and the downside risk is low, but they should be treated as hypotheses.
What this means for you: Experiment cautiously. Set a specific timeframe and success criteria before starting. If it doesn’t deliver results within that window, move on without guilt.
When This Applies
Reference the evidence grade whenever you’re deciding:
- Which protocol to start with. Grade A protocols have the highest certainty of payoff. If you’re overwhelmed, start there.
- How much to invest. An A-grade protocol deserves more time and commitment than a C-grade experiment.
- Whether to continue. If a B-grade protocol isn’t working after a fair trial, the evidence supports trying something else. If an A-grade protocol isn’t working, the issue is more likely execution than approach.
- What to recommend to others. A-grade protocols are safe to share broadly. C and D-grade protocols should come with caveats.
How Grades Are Assigned
Each protocol is evaluated on five dimensions:
- Study quality. RCTs and systematic reviews score higher than observational studies or expert opinion.
- Replicability. Has the finding been reproduced across different populations and contexts?
- Consensus. Do relevant professional bodies agree on the recommendation?
- Effect size. Is the benefit meaningful and practical, not just statistically significant?
- Risk profile. What’s the downside if the recommendation turns out to be wrong?
Grades are reviewed when protocols are updated (see review cadence thresholds on each protocol page).
Related
- Minimum Viable System: All five essential protocols are Grade A or B
- Optimize Sleep: Example of a Grade A protocol with strong evidence
- Curate Information: Example of a Grade C protocol with preliminary evidence
- System Failure Modes: What to do when protocols aren’t working