How the teaching model, the AI's guardrails and the 16 domains work together. For the short version, see the main Northstar page.

How the system is split

Part What it does
Learner inputs Share of each group in the training data, decision bar, factors on or off, algorithm
Scenario data Factors, how strongly each one stands in for a group, group labels, real-world grounding
Teaching model Produces every number on screen. The same setup always gives the same numbers. Labelled "teaching numbers, not real measurements"
Outputs Approval rate per group, fairness gap, what drove it, next steps
AI narrator and study material Receives the exact numbers. Explains, quizzes and answers follow-ups

AI guardrails: never invents numbers, plain language, hedged claims, no verdicts.

The 16 domains

The first concept had four scenarios. I grew it to sixteen so learners could find a case close to their own life. Learners can also upload their own CSV, which stays in the browser.

Anatomy of a domain: Hiring

Every domain uses the same template, so the model stays identical and only the story changes.

Promise See how an AI screens job applicants for interviews
Outcome "approved for an interview", used in every label and sentence
Groups Men and women on the gender lens. Race is the second lens
Teaches A factor that looks neutral, like past pay, can carry a group's history with it
Real world Real résumé screeners have down-ranked applicants linked to women's colleges and clubs
Factors Experience (no link to gender), education (weak stand-in), age (no link to gender), previous salary (strong stand-in)

Plain words for technical terms

Machine-learning term What learners see
Dataset composition How balanced the training data is
Decision threshold How strict the decision bar is
Feature selection What the AI is allowed to look at
Proxy variable A factor that stands in for a group

Rules for sensitive domains

In health, justice, benefits, housing and livelihood domains, the AI narrator:

  1. Opens by saying this is a simplified model of a documented pattern, not how any real hospital, court or agency works.