You MAP test every 6 weeks? We only do it 3 times a year. It is not uncommon to fluctuate- he could have just had a bad day. If you see a continual decline or a more drastic drop I would be concerned. Yes boredom could contribute but since this is the test that will test to their knowledge limit it would be something that would challenge him. I like it when ds comes home and we always talk about what the hardest questions were. I would see how he felt about it and look at the NWEA site, find the score number for the grade that matches his percentage-( the have a chart- you can google the 2011 rit charts) then look at the page they have that gives score ranges with problem examples(don't remember what it is called but on the NWEA site) and see if you think if it is in his range or out of his range. Hope that helps!
Brandy