Silly - alternatives for academic writing

Last week, one of our students, Andressa, asked for a synonym of a word. "Look up the dictionary", I hear you say... Well, not that simple...
She wanted to say - in academic terms - that a certain book seemed to be a little silly in the beginning. Ok, how do you say "silly" in an academic style? The dictionary doesn´t give you a solution, does it?
COCA does...
We checked www.americancorpus.org, inserted the search string [=silly] (which means, give me synonyms of silly!), chose ACADEMIC and.....

here´s what we got:

1		JUVENILE [S]	1580
2		TRIVIAL [S]	707
3		MEANINGLESS [S]	604
4		STUPID [S]	482
5		RIDICULOUS [S]	363
6		IMPRACTICAL [S]	316
7		SILLY [S]	288
8		POINTLESS [S]	182
9		MINDLESS [S]	157
10		SENSELESS [S]	132

For examples of each word in context, just click on it.

Have fun!;-)