gistfile1.js

var _ = require('lodash');
var natural = require('natural'),
    classifier = new natural.BayesClassifier();

// First item denotes "changed motor oil"
var notes = [
  [true, 'Change oil, oil filter, air filter, spark plugs'],
  [true, 'Change oil, oil filter. 4qt Rotella T6, 0.5 Mobil 1 5W-40'],
  [false, 'Change gearbox oil, rear drive oil, valve adjustment, torque heads'],
  [false, 'Change transmission oil'],
  [false, 'Change headlight fluid']
];

_.each(notes, function(n) {
  classifier.addDocument(n[1], (n[0] ? 'changed motor oil' : ''));
});

classifier.train();

console.log(
  classifier.classify('Change power steering fluid')
);