Narrowing Curricula -- Or Not?

The Post ran an article over the weekend about how elementary schools have been cutting back on instructional time in science to meet NCLB demands in reading and math, and how this might, possibly, come back to bite them when NCLB starts holding them accountable for science. A logical enough starting point, but the story is mostly based on local anecdote and the obviously-not-neutral views of people like the executive director of the National Science Teachers Association. The only real hard data is this:

Between the 1999-2000 academic year and 2003-04, the most recent date available, the average time spent weekly on science instruction in elementary schools dipped from 2.6 hours to 2.3, according to the U.S. Education Department.

But of course, the majority of that time period was pre-NCLB, so that doesn't tell us much. Then, near the back of the piece, the author notes:

National science performance has not declined in the elementary grades under the No Child act, according to the National Assessment of Educational Progress, the only ongoing national effort to test public school students. The percentage of students rated proficient or better in fourth-grade science increased from 24 percent to 27 percent in Maryland from 2000 to 2005, perhaps a reflection of more rigorous instruction across the curriculum. In Virginia, proficiency rose from 32 to 40 percent in the same span.

To which AFTie Beth wonders, after criticizing curriculum narrowing as "shockingly shortsighted,":

But what to make of the fact that NAEP science scores rose at exactly the same time that schools were supposedly decreasing time allotted for science instruction? Maybe the increased focus on language arts has increased students’ comprehension so much that they’re doing better on the comprehension-dependent science questions. Or maybe we can conclude that we don’t have to add science to AYP in order to see scores rise. Or maybe two years of test data is not enough from which to draw major conclusions?

Or maybe--just maybe--when the premise of an article is one thing, and the data suggest the opposite, the premise might be, you know, wrong. Maybe curriculum narrowing is happening, and maybe it's bad for science learning, I don't know for sure. But nobody else--at least, nobody involved in the Post article--seems to know either.