title: How many seconds need to pass before a 'loading bar' is warranted?
body: <p>Hello wonderful programmers of the world!</p>
  
  <p>Forgive me in advance if you feel this is too subjective.</p>
  
  <p>I'm building an app for the iPhone. At a certain point the user hits a button to process some data during which there is no animated feedback. Just the buttons disable and one button changes it's name to 'Processing data'. After about 5 or 6 seconds pass the buttons are enabled and life goes on. </p>
  
  <p>Do you think I need some animation during this 'processing period?' Is there a rule of thumb about this? What would you say is the threshold for needing to include a 'loading bar' in your program? 5 seconds? 8 seconds? 2 seconds?</p>
  
  <p>Thanks</p>