title: How to read the classifier confusion matrix in WEKA
body: <p>Sorry, I am new to WEKA and just learning.</p>
  
  <p>In my decision tree (J48) classifier output, there is a confusion Matrix:</p>
  
  <pre><code>a    b   &lt;----- classified as
  130  8     a = functional
  15   150   b = non-functional
  </code></pre>
  
  <ul>
  <li>How do I read this matrix? What's the difference between a &amp; b?</li>
  <li>Also, can anyone explain to me what domain values are?</li>
  </ul>