How many defects are actually detected by regression testing?
Nobody knows for sure, but expect that a 5% functionality change in a 1000 suite test will reveal 5-25 new defects. • I’ve heard that capture/playback tools are dangerously invasive? Exactly how do they really work? CAPBAK/X works with X windows on UNIX by using the XtestExtension1 or Xtrap extension to the X11 server (display driver). You can tell which extension(s) you have using the “xdpyinfo” command on your UNIX machine. CAPBAK/X also uses a special version of the Xt toolkit for ObjectMode recordings from X/Motif GUIs. On Windows machines CAPBAK/MSW uses built-in features of the Windows 3.x, Windows ’95 or Windows NT operating systems. Every kind of recording mechanism is to some extent “invasive,” but most users don’t consider this very low-level of interaction with the underlying operating system software much of a risk.
