DALLAS – Dozens of Texas schools appear to have cheated on the state’s redesigned academic achievement test, casting doubt on whether the accountability system can reliably measure how schools are performing, a newspaper found.

An analysis uncovered strong evidence of organized, educator-led cheating on the Texas Assessment of Knowledge and Skills at schools in Houston and Dallas, along with suspicious scores in hundreds of other schools, The Dallas Morning News reported.

Texas education policies on student accountability became the model for the federal No Child Left Behind law enacted after President Bush’s election in 2000.

The newspaper searched for schools with unusual gaps in performance between grades or subjects, saying research has shown that schools that are weak in one subject or grade are typically weak in others.

It found, for example, that the fourth-graders at Sanderson Elementary School in the Houston Independent School District scored extremely poorly on the math TAKS test this year, rating the school in the bottom 2 percent of the state.

The school’s fifth-graders ended up with the highest scale scores on the math TAKS of any school in Texas, with more than 90 percent of the students getting perfect or near-perfect scores.