Jinyoung,
Are you using Mac or Windows PC.
Combining output of many .cha files into one KWAL output will create a problem of having many media file names in one output file. As far as I can tell PRAAT allows only one media file associated with one file.
You can add +u option to KWAL to combine all KWAL outputs into one output file.
You can use +d1 option "kwal *.cha +sthe +d1 +f +u" to find utterance with word "the" and output results into just one file. You can then open KWAL output file and place text cursor at the end of any bullet and use menu "Mode->Send to sound analyzer" to send that bullets to PRAAT.
if you use KWAL command with +d +o@Media +f +u options, then bullets in combined KWAL output will not be associated with the right media file.
Once you create KWAL output file open it in CLAN and select menu "Mode->Expand bullets" to see how bullets look. The +d1 option will create bullets that contain the media filename within them. Otherwise, bullets rely on @Media header to tell them the name of the media file.
There is also a CHAT2PRAAT command that will convert CHAT .cha file into PRAAT . textGrid file.
The error message "Can't locate media file or recognize media format" means that media file specified does not exist on the hard disk. Make sure that the filename on hard disk matches exactly the name specified in @Media header or inside extended bullets that are created with +d1 option. Look for some hidden character(s) or space characters in the media filename. If your computer hides file extensions of common file types as both Mac and Windows PC do, then the filename on hard disk might not match.
If you have more questions, then please email them directly to me
spe...@andrew.cmu.edu. Also, please keep in mind that this is weekend.