Critical thinking
Dialectica
Find weak premises, challenge fallacies, and inspect an argument’s structure.
Adaptive sparring · argument graphs · spaced review
Open Dialectica →NivantLabs / Deliberate practice
Learn the principle.
Test a different move.
Build practical intuition through explainable challenges, scenario experiments, and spaced review. Start without an account; learning history stays in this browser.
Free practiceInstallable web appsOffline after first visitExportable learning history
Financial decisions
FinSim Pulse
Explore a fictional financial timeline and compare the consequences of different decisions.
20-year models · counterfactual replay · local Monte Carlo
Open FinSim Pulse →Software engineering
BugHunt Dojo
Investigate service logs, diagnose incidents, and write patches against executable fixtures.
Incident lab · patch editor · isolated fixture tests
Open BugHunt Dojo →Communication
Pragmatica
Rehearse negotiations and difficult conversations with branching scenarios and reflection.
Conversation RPG · local recording · optional on-device AI
Open Pragmatica →Quantitative intuition
NumeriQ
Practice mental shortcuts, probability, and estimation while tracking confidence.
Generated drills · timed practice · calibration
Open NumeriQ →Supervised fictional training
MedTriage Sim
Explore selected adult triage criteria and Bayesian reasoning using explicitly fictional exercises.
Fictional cases · counterfactual reassessment · synthetic probability lab
Open MedTriage Sim →What these exercises measure
Profiles summarize your practice attempts and review history. They are not validated assessments of cognition, financial capability, language proficiency, engineering readiness, or clinical competence. Financial scenarios use simplified fictional assumptions. MedTriage Sim is a partial supervised-learning exercise, not a clinical decision tool.
Optional on-device AI requires WebGPU and an initial model download. Browser dictation is separate and can send audio to the browser’s provider only when you choose to enable it. Core authored exercises do not require AI.