For our latest story on testing irregularities in New Orleans, The Lens analyzed test security reports from 2012 and 2013, the most recent completed testing years, and compared them to the number of tests taken at each school.

The state and its vendor, Data Recognition Corp., check all tests for potential plagiarism. For erasures, the state checks only LEAP, iLEAP, and GEE tests; sample sizes for other types of tests are too small for this analysis to be valid.

We changed how we calculated the rate of testing problems because officials with the state Department of Education disputed the method we used for a previous story.

The Lens looks at school standardized testing:New Orleans schools abate erasures on standardized tests, but plagiarism persistsLouisiana follows experts’ tips to prevent, detect standardized test cheating

For that story, we calculated the percentage of schools that had tests voided for testing problems. Three testing experts said that method was sound. State officials, however, argued that we should look at the percentage of tests instead.

Both methods show New Orleans is an outlier.

When analyzed by our prior method, the percentage of schools flagged for plagiarism in Orleans public schools was twice as high as the rest of the state in 2012 and 2013. Under the new method, we found that the percentage of tests flagged for plagiarism was three times higher in New Orleans.

For answer changes, both methods yielded a rate twice as high in Orleans than the rest of the state.

We also examined the number of tests voided for administrative errors or self-reported problems.

For 2012, both ways of measuring yielded a rate three times as high in New Orleans as the rest of the state. In 2013, Orleans was 1.5 times higher than the rest of the state under the old method, and twice as high under the new one.

Using five years of data, we looked to see which schools have had repeated problems. We excluded schools that state officials flagged on test-taking days because they tend to visit schools that have had problems in prior years, thus skewing the sample under study.

We discovered an error in the data that the state provided. Milestone SABIS was counted in  Orleans Parish figures for 2013. But it moved to Jefferson Parish in the 2012-2013 school year.

The Lens informed the state of the inaccuracy on March 20 and followed up several times. Three months later, the state has not provided the correct information.

Still, the number of tests taken at Milestone SABIS is too small to have a significant impact on the percentages in our analysis. Fewer than 300 students were in testing grades in the 2012-13 year, according to enrollment numbers.

Further questions? Email me at jwilliams@thelensnola.org.