title: How to calculate differences scores with R?
body: <p>So I have 2 sets of data, each comparing a specific category, like so:</p>
  
  <pre><code>Category : Solution 1 : Solution 2
  1: 5 : 6
  2: 7 : 6
  3: 4 : 4
  4: 8 : 9
  </code></pre>
  
  <p>How do I calculate the difference scores using R specifically? Somehow I need to load the data them calculate <code>solution1 - solution2</code> I believe.</p>