title: REST api design to retrieve summary information
body: <p>I have a scenario in which I have REST API which manages a Resource which we will call Group.
  A Group is similar in concept to a discussion forum in Google Groups. </p>
  
  <p>Now I have two GET access method which I believe needs separate representations.</p>
  
  <p>The 1st GET access method retrieves the minimal amount of information about a Group.
  Given a <em>group_id</em> it should return a minimal amount of information like </p>
  
  <pre><code>{ 
      group_id: "5t7yu8i9io0op",
      group_name: "Android Developers",
      is_moderated: true,
      number_of_users: 34,
      new_messages: 5,
      icon: "http://boo.com/pic.png"
  }
  </code></pre>
  
  <p>The 2nd GET access method retrives summary information which are more statistical in nature like:</p>
  
  <pre><code>{ 
      group_id: "5t7yu8i9io0op",
      top_ranking_users: {
        [ { user: "george", posts: 789, rank: 1 }, 
          { user: "joel", posts: 560, rank: 2 }  ...]
      },
      popular_topics: {
        [ ... ]
      }
  }
  </code></pre>
  
  <p>I want to separate these data access methods and I'm currently planning on this design:</p>
  
  <pre><code>GET /group/:group_id/
  GET /group/:group_id/stat
  </code></pre>
  
  <p>Only the latter will return the statistical information about the group. What do you think about this ?</p>