select

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  therapists: [ {id: 1, name: "Elli"}, {id: 2, name:"Patricia"}],
  therapist: {id: 1, name: "Elli"},
  actions: {
    selectTherapist(therapist_id){
      this.set('therapist', this.therapists[therapist_id-1])
    }
}
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<div>Active Therapist: <b>{{therapist.name}}</b></div>
<select onchange={{action 'selectTherapist' value="target.value"}}>
{{#each therapists as |t|}}
<option value={{t.id}}>{{t.name}}</option>
{{/each}}
</select>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.4.16",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember-template-compiler.js"
  }
}