title: Missing Values in Weka --
body: <p>I'm using adult data from UCI <a href="http://archive.ics.uci.edu/ml/datasets/Adult" rel="nofollow noreferrer">Here</a>, when I converted it to excel file ==&gt; then import it in weka
  weka didn't recognize the missing values (which tells Missing:0 (0%)) ,
  but the adult data contains missing values with &quot; ?&quot; value...</p>
  <p>I checked the value in weka it also contains &quot; ?&quot; so, how can I replace all &quot; ?&quot; to &quot; &quot; !!!</p>