How We Compare

List of 3 frequently asked questions.

• To 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?

  In nearly every subtest, year after year, Central students equally or outperform other private schools. To highlight a few specifics, the median score in every grade and area tested is in the top 25% of the nation or higher. The median score of our 4th-6th graders in writing mechanics is an average of 3 points above other private school students.
  
  

  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 CTP scores confirm we are indeed teaching children what they need to know in order to succeed in the secondary school environment.