Abstract

AI Study Design Methodologist

Study design, written like a protocol.

Your next study fails if the design is weak. Paste your research aim — get power calculations, causal structure, and reviewer rebuttals in 20 minutes. Not templates. A methodological consultation.

Start Consultation → View Study Types

Target Trial

Clear estimand and eligibility

Causal DAGs

Bias-aware confounder control

Reviewer Prep

Preempt common critiques

1.Live consultation

Describe your research question and get structured methodology guidance.

ProtoCol Consultation — Online

📄

Welcome to ProtoCol. I'm your study design consultant.

Tell me your research question, and I'll help you design a rigorous study. I'll challenge your assumptions, identify threats to validity, and recommend the right methodology.

What would you like to investigate?

2.Study design types

Select the structure that best matches your question.

RCT

Randomized Controlled Trial

Gold standard for causal inference when ethical equipoise and blinding are feasible.

Cohort

Prospective or retrospective

Follow exposed vs unexposed over time to estimate incidence and relative risk.

Case-Control

Retrospective comparison

Efficient for rare outcomes. Careful control selection is critical.

Cross-Sectional

Point-in-time snapshot

Useful for prevalence and hypothesis generation; temporality is limited.

3.Methods appendix

Common causal inference methods explained in plain terms.

PSM: Match treated and untreated on propensity scores to reduce confounding.
IPW: Reweight observations to emulate a randomized experiment.
IV: Use an instrument correlated with treatment but not with the outcome directly.
RDD: Exploit sharp assignment cutoffs for quasi-experimental estimation.

4.Pricing

Start free. Upgrade when you need more depth and volume.

Monthly

Annual

Replace a $500 methodology consultation with a structured protocol review.

Free

$0/mo

2 consultations/month
All study design types
Basic validity analysis
Study design checklist
Community support

Researcher

$29/mo

Unlimited consultations
All study designs + causal methods
DAG builder & power analysis
Rebuttal letter generator
Export PDF reports

Lab / Team

$99/mo

Everything in Researcher
5 team seats
Priority support
Team usage dashboard
Custom methodology rules

5.Feature comparison

Included capabilities by plan.

Feature	Free	Researcher	Lab / Team
AI Consultations	2/mo	Unlimited	Unlimited
Study Design Types	All types	All types	All types + custom
Causal Inference (PSM/IPW/IV)	✗	✓	✓
DAG Builder	✗	✓	✓
Power / Sample Size Calculator	✗	✓	✓
PDF Report Export	✗	✓	✓
Rebuttal Letter Generator	✗	✓	✓
Team Seats	1	1	5
Priority Support	✗	✗	✓
Custom Methodology Rules	✗	✗	✓

Need institutional licensing or 10+ seats? Contact us for custom pricing.