Limitations of the ITBS

Following are some of the most common criticisms of the Iowa Tests of Basic Skills (ITBS), used in elementary school, and the Tests of Achievement and Proficiency (TAP), used in high school.

• ITBS/TAP scores do not tell what students know or are able to do. They only tell how a child compares to other students.
  
  The ITBS/TAP are what are called “norm-referenced tests.” This means they are designed to sort and rank students on a bell-shaped curve — in which only a few students score very high, only a few score very low, and most score in the middle. The tests are also designed so that half the students taking the test will end up below average, and half above average. This guarantees that half of the students will always score “below average” on such tests.
  
• ITBS/TAP tests use obscure or tricky questions. If the driver’s test were used to sort or rank people, it would have to include some questions not everyone would get right. In such a case, it might ask, “How do you get from Union Station to O’Hare Airport?” or, “What is the chemical composition of diesel fuel?”
  
  ITBS/TAP tests also include some questions which are designed to sort out kids. A close look at these kinds of questions shows that they may have more than one answer which many people would consider correct. For example, look at the following question:
  
  Choose the word that best completes this sentence – A sage individual is:_ touchy _ testy _ old _ wise.
  

  The test maker says the right answer is “wise.” This kind of question could trip up many students, including those from cultures strongly identifying wisdom with age.

• The margin of error of ITBS/TAP test results is too great to use those results alone to make important educational decisions.
  
  Test scores are an estimate; they are not exact. This margin of error is one reason that the Riverside Publishing Company tells school districts not to use the ITBS/TAP test scores as a single basis for making decisions like grade retention. Otherwise, one wrong answer on the tests can make the difference in whether a child is promoted or retained. Despite these cautions, the Chicago Public Schools uses these standardized tests to make decisions about promotion.
  
  Experts agree that other information, including teacher and parent input, must be considered when making an important decision such as retaining a student.

This information is adapted from an informational brochure published by the Local School Councils Summit in conjunction with the testing reform group FairTest. The LSC is a coalition of Chicago parent and school reform groups including the Chicago Association of Local School Councils, Designs for Change, PURE, Teachers’ Task Force, Cross-City Campaign for Urban School Reform, Schools First, and the Lawyers’ School Reform Advisory Project.