SAT scores for Lancaster County public school students have declined for the third year in a row.

Members of the Class of 2011 scored 16 points lower, on average, than their predecessors in the 2010 graduating class, averaging 1,481 of a possible 2,400 points on the test of reading, math and writing skills.

The decline follows drops of 5 points and 14 points, respectively, in the previous two years on the test, which colleges and universities consider a key indicator of a student's academic readiness.

Average scores in the county have dropped by 35 points since 2008, although students here continue to score slightly higher than their peers statewide. As in previous years, their average scores lag behind the national average.

The average for the 1.65 million students in the U.S. who took the test dipped 9 points, to 1,500, while the state average was unchanged, at 1,473.

County school officials are generally at a loss to explain the overall declines here, although they point out that more students, in general, are taking the SAT than in previous years as high schools increase their emphasis on college attendance.

In general, the larger the test-testing pool, the higher the likelihood scores will decline.

Of the county's 17 public high schools, 12 increased their participation rates in 2011; of those 12, eight had lower average scores than in 2010.

Elizabethtown, Ephrata, Octorara and Penn Manor high schools were the exceptions, boosting both their participation rates and their scores by as much as 33 points.

As in previous years, many of the swings in scores followed changes in the opposite direction the previous year.

The total average for Pequea Valley students, for instance, dropped by 73 points in 2011, one year after it rose by 72 points. Octorara followed a similar pattern, boosting its scores by 33 points a year after the 2010 average declined by 47 points.

This year's increase came despite an additional 44 Octorara students taking the test.

Octorara High School Principal Scott Rohrer said it's difficult to compare results from one year to the next because every graduating class is different.

But he said Octorara's teaching staff has "made a concerted effort to enhance critical thinking skills" for all students and has challenged more pupils to take advanced courses, which may have helped boost the 2011 scores.

Solanco principal Brian Gallagher said he could not pinpoint what caused scores at his school to decline by 53 points in 2011, to 1,426, after rising by 15 points in 2010.

"Each year, we evaluate the results of these tests to see what we as a staff can do to better prepare Solanco students," he said in an email. "This drop in SAT scores will have us looking at curriculum and instruction at the junior and senior levels."

For the first time in several years, a high school other than Manheim Township had the county's highest average. Warwick students earned that honor with a total average of 1,592 points, a 20-point increase from 2010's total.

That exceeds a new target of 1,550 established by the College Board to indicate whether students are likely to be successful in college.

Called the College and Career Readiness Benchmark, 1,550 is the level at which a student has at least a 65 percent likelihood of achieving a "B" average or higher in his or her first year of college.

Students who meet or exceed that score also have a substantially higher college retention rate than those who don't hit the target.

In addition to Warwick, students at Manheim Township (1,587 average) and Lampeter-Strasburg (1,562 average) high schools exceeded the benchmark, while students at Elizabethtown, Ephrata and Hempfield were just shy of the mark.

The lowest scores for 2011 were for McCaskey (1,194) and Columbia (1,307) high schools, which both have been trying to increase SAT participation in recent years.

Scores for McCaskey students declined by 65 points, the fourth drop in a row since 2008, while Columbia's average was down by 26 points.

The number of McCaskey students taking the test has risen by 66 percent since 2006.

The College Board cautions that SAT scores should not be used to compare one school with another because the results are greatly affected by demographics and other "nonschool" factors.

But even school officials admit they like to see their students outperform their peers across the state and across the county on the SAT.

"It's not a true indication of your academic program because not all students take (the SAT)," said Michael Leichliter, superintendent of Penn Manor School District. "But we have a goal to increase those scores because I do think they reflect on a district and its programs."

Leichliter said the public should keep in mind other academic measures, including graduation rates and PSSA, ACT and advanced-placement test scores, when evaluating the academic rigor of a school.

bwallace@lnpnews.com