How Do We Compare?

We treasure the learning environment at Central Christian School. We value the love, the grace, and the community we experience together as an elementary school. However, those factors are just part of our responsibility as an institution preparing students for secondary school. As educators, we are called to measure the learning happening in this unique environment.

How do we measure learning progress? ERB CTP4 standardized testing is one of many ways we quantify the abstract process of learning. CTP4 is one of the most challenging academic testing programs and is an excellent tool to measure our students' growth. It also provides a way for us to compare ourselves to other schools in the St. Louis region and across the United States.

When diving into statistics, interpretation can be complicated. For clear communication, it is necessary to define praticular terms about whom we are compared and what we compare before presenting exactly how we, as a school, compare.

Whom are we comparing?

Norm Group: A norm group is a group of students to whom your child is being compared - usually other students in the same grade who are taking the same test. 

Independent Norm Group: These students are the other students in private schools that use the CTP tests. Most private, ERB-member schools have tuition and fees 100% to 150% more than Central Christian School. In addition, many of these schools lack the racial, socio-economic, and cultural diversity that Central stewards.

Suburban/Public Norm Group: This group identifies students in public school districts that use the CTP tests. These schools are typically in suburban areas, are well-funded, have homogeneous populations, and compete for the highest achieving students with local private schools.

National Norm Group: Finally, this group represents a statistical sampling of students at the appropriate grade level in all schools in the nation - large and small schools; wealthy and disadvantaged schools; urban, suburban, and rural schools.

Central Christian School is unique. We are distinct among ERB-member schools because of our modest tuition, broad admissions policy, and student diversity. We are also distinct among Christian schools because of our ability to serve children with learning differences while offering a challenging academic experience to all of our learners. As we compare ourselves to other private and public schools, it is important to remember these differences.

What are we comparing?

Scale Score: A scale score is a conversion of a student's raw score on a test to a common scale that allows for a numerical comparison among students and from year to year.

Percentile Rank: A percentile distributes all the scale scores into 100 groups having equal frequencies. You cannot average a percentile rank. The percentile rank is not a percentage or percent correct. 

Average Score: This is a middle point calculated by dividing the sum total of a set of scores by the number of scores. Also called the mean, this works best with large sample sizes.

Median Score: This score is a middle point calculated by lining up all scores from least to greatest; the median is the score in the exact middle. Medians work best to compare small sample sizes and percentile ranks.

How do we compare?

Central's third through sixth grade students participate in the ERB CTP4 each January, and they have a lot of success! In nearly every subtest this past school year, Central students outperformed public and private schools. Moreover, Central students as a whole maintained or grew in each subtest compared to the previous year. This data confirms our unique, integrated curriculum taught through the lens of a Christian worldview is preparing children well for secondary school. Central students are learning what they need to know.

To highlight a few specifics, 5 of Central's 39 third grade students earned a perfect scale score in Reading Comprehension. In sixth grade, 75% of our students scored above average in Writing Concepts and Skills. School-wide the prime success is Quantitative Reasoning and Math, with Central students outperforming public and private schools, at times, by 15 points.


The infographics illustrate average scale scores comparing 2014 - 15 Central third grade scores to private and national schools. (There is no suburban/public norm for third grade.) Also included are median scores of fourth through sixth grades for Central, private, suburban public, and national norm groups.

Standardized testing is only a small part of the academic experience at Central Christian School. We will always hold true to teaching relevant content from a Christian worldview, implementing research-based instructional practices, and measuring our progress and growth in a challenging academic environment. However, the data gathered from our students' ERB CTP4 scores confirm we are indeed teaching children what they need to know in order to succeed in the secondary school environment. Thank you for entrusting your children to us! It is a privilege to partner with you as we develop lifelong learners.