Arne Duncan, U.S, Education Secretary, says those policy changes may cause a short-term drop in test scores as the new procedures are implemented, but they are designed to be of great benefit over the years.

Duncan adds, “Big change never happens overnight.  I’m confident that over the next decade, if we stay committed to this change, we will see historic improvements.”

The testing has been administered to public and private schools every two years since the early 90’s and is considered the most consistent measure of students progress.

Researchers caution that it is too soon to predict if a trend is beginning, or if this is just a temporary drop in test scores.  More analysis needs to be completed to understand the reasoning behind the declines.

The test results for 2015 show that 64 percent of fourth-graders and 66 percent of eight-graders are not proficient in reading skills, and the numbers for not being proficient in math are 60 and 67 percent, respectively.