First-time poster. My apologies in advance.
I've imported an avi file and created a composition from it. As far as I can tell all of the settings are in line with the initial avi settings, but the quality degrades the moment I add it to the composition. There are screen shots involved, and the text is legible in the original avi file but becomes illegible in the composition.
The avi is 720x480 (0.91) 29.97 fps
The composition is NTSC DV, 720x480, D1/DV NTSC (0.91) full quality.
Any ideas would be greatly appreciated.
 The footage isn't interpreted correctly ... right click on it in the project panel, select "interpret footage" and make sure everything in that window is correct (particularly interlaced or non-interlaced).
 There's a viewing setting wrong that's making the footage look bad in the comp viewer even though there's nothing actually wrong ... double-check that your comp viewer is set to full resolution (vs. half or quarter) and that the layer resolution is set to full (vs. draft).
 The AVI is in some kind of wonky codec ... the AVI format is only a wrapper (like MOV) so AVIs can be made with any one of very many different codecs. If that is the problem, the easiest solution is to transcode the file to a more standard codec.