var Todo = Backbone.Model.extend({

  defaults: {

    title: '',

    completed: false

  },

​

  initialize: function(){

    console.log('This model has been initialized.');

    this.bind('change:title', function(){

        console.log('Title value for this model has changed.');

    });

  },

​

  setTitle: function(newTitle){

    this.set({ title: newTitle });

  }

});

​

var myTodo = new Todo();

​

// Both of the following changes trigger the listener:

myTodo.set({'title': 'Check what\'s logged.'});

myTodo.setTitle('Go fishing on Sunday.');

​

// But, this change type is not observed, so no listener is triggered:

myTodo.set({'completed': true});

console.log('Todo set as completed: ' + myTodo.get('completed'));