by Brett Vaden

There are many reasons why private schools employ standardized tests for students in lower grades:

  • They want to have a measure for their student’s learning.
  • They want to know how well they are doing their job.
  • In some states, they are required to do it.
  • Not least of all, having a standardized test can boost a school’s credibility in the eyes of parents and prospective families.

Assuming a third-party assessment can be a valuable asset for a private school to use, what kinds of standardize tests are out there, and which should you use?

Norm-Referenced Tests

Norm-referenced standardized tests are made to show how students compare with a representative sample, or norm, of their peers. Tests like these place test-takers’ results on a bell-shaped curve. A score of 50 would be considered the average, placing a student in the 50th percentile. The higher a student’s score is above the average, the more he or she outranks others in the same general age-group.

Schools who use norm-referenced tests should recognize that the purpose is to reveal how students compare with others across the nation in the same grade level, not to prove how well the school is teaching its particular curriculum. A school shouldn’t look at their results to see how well teachers are teaching the content of their subjects. Rather, they should use the results to see how well students are growing intellectually and skill-wise against students in other schools.

For private schools and charter schools with the freedom to choose their own standardized test, the biggest factors to consider when choosing one are relevance, reputation, and price.

The test should be fairly relevant to the academic objectives of your school for each grade level; the fit doesn’t have to be perfect, but you don’t want too much of the test to cover skills or content wildly different from what’s been taught in your classrooms.

The test should also have a wide, solid, and long-standing reputation. For example, the Iowa Test of Basic Skills (ITBS) is taken by a large number of students both nationally and internationally, is well-attested, and has been around since 1935.

Price is also a factor. Some states pay up to $65 a student for standardized tests (Hawaii pays $105 per student!). While this is a drop in the bucket in overall spending in public schools, smaller private schools will want more affordable options. One option is to purchase scoring forms yearly, but to buy the test booklets once and use them year after year (making sure students know not to mark on them). Public schools often give four or five different standardized tests a year, but for private schools one should be adequate.

These are commonly used norm-referenced tests: California Achievement Test, Metropolitan Achievement Test, Iowa Test of Basic Skills, Comprehensive Test of Basic Skills, Terra Nova, and Stanford Achievement Test.

Our recommendation to schools modeling themselves on the CLSA flagship, Highlands Latin School, is to use the Iowa Test of Basic Skills.

Criterion-Referenced Tests

The other kind of standardized test is criterion-referenced, meaning that results are compared to a set criterion, or standard, which is set by the test-makers. Criterion-referenced tests are commonly used by states who set certain standards they want students to meet.

In contrast to norm-referenced tests, the purpose of criterion-referenced tests is not to rank students nationally but simply to show how they are meeting particular bench-marks in knowledge and skills.

For many private schools that have decided their own standards, their own self-made tests may do. Classical curriculum publishers like Memoria Press provide schools with well-crafted, ready-made assessments.


Michelle · July 11, 2019 at 10:43 am

Hi Brett. I have an ethical question. Do you find it common practice for schools(public and/or private) to charge students a mark up of 200% for the TerraNova? Students at a private school in our city are paying $125 per test to the school. I see the TerraNova tests are $43 each, with a 10% discount for buying in bulk. It is administered during the school day…costs aren’t going to paying teachers over time. Is this unethical or common practice? Thank you.

Susan Goldstein · October 11, 2017 at 1:33 pm

We have been using the Iowa Test for many years and would like to try a different standardized test. Any suggestions?

    Paul Schaeffer · April 30, 2018 at 10:42 am

    Hi Susan, sorry for the late reply. As reference above, we prefer the ITBS but if it isn’t working for you, some of our schools have liked the CTP from ERB.

Susan Goldstein · October 11, 2017 at 1:32 pm

We are looking for a different test than the Iowa Test. Any ideas?

Masuda Vohra · January 29, 2017 at 6:48 pm

Hi, I am looking for a criterion based standardized test for our K-8 private school. Can you recommend specific ones. We have been using IOWA up until now.

    paul · January 30, 2017 at 9:32 am

    Hi, we in fact recommend the ITBS (Iowa Test of Basic Skills), but only the core battery. We have many schools that find it to be appropriate, not overwhelming, and accurate.

David Hawkins · April 28, 2016 at 9:50 am

I’m kind of new to the private school system and idea so this info is very helpful. I did not know that I needed to pick a standardized test for any student that I put through the school. I’ll have to talk to their teachers and see what we can come up with that will best prepare them for the future. Thanks for the info!

    Brett Vaden · May 2, 2016 at 4:15 pm

    You’re very welcome, David!

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