i've searched but it was hard to find. i can't find lessons or columns about this either. are there any good exercises to increase the accuracy?
play a scale in 3, 4, and 5 note grouping. like for 3 note grouping you play the first 3 notes then start on the second note and play the next three and so on and so forth.
The newest guitar world has a 4 part article that is all about improving your alt picking with examples.

I couldn't find it on there web site but part 3 is in the newest mag.
Jackson RR24M - EMG ALX w/ ABQ installed
Ibanez Xiphos - stock
LTD Alexi 600 - stock
Ibanex RG - Tone Zone(bridge), PAF Pro(neck)
Blackstar HT-20H
Fulltone OCD
MXR 10 Band EQ
Try this. Use strict alternate picking.

   d u d u d u d u d u d u d u d u 

It's an A barre chord form with an added 3rd. You could do it in any key. Once you get the hang of that, start with an up stroke instead of a down. Then you could play each note twice before hitting the next note (starting with a down, and then starting with an up), then 3 times, and four times. Use a metronome and don't change the speed of the metronome, just sub-divide the notes. So for just one note, just do quarter notes, then each note twice, do eighth notes, then triplets, and then 16th notes.
Quote by Geldin
Junior's usually at least a little terse, but he knows his stuff. I've always read his posts in a grouchy grandfather voice, a grouchy grandfather with a huge stiffy for alternate picking.
Besides that, he's right this time. As usual.