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Score Interpretations

About the Scores

Scores for all content areas tested in the STAR program are reported by grade level for the state, and each county, school district, and school. Results will include: for grades 2 through 8, scores in total reading, written expression (total language), spelling, and total mathematics; for grades 9 through 11, scores in total reading, writing (total language), mathematics, science, and social science. The report will show scores by grade level and content area in two ways: 1) for all students tested in the group, and 2) for limited English proficient (LEP) students. The total reading score includes vocabulary and comprehension. The total language score includes language mechanics and language expression. The total mathematics score includes problem solving and procedures.

In order to protect student confidentiality, no scores are reported for any group of 10 or fewer students.

The results posted on this web site should be considered preliminary and are subject to revision. Date of last revision: June 30, 1998

Types of Scores Reported

For each school, district, county and for the state, the following types of scores are reported by grade level and content area:

  • NPR (national percentile rank) of the "average" student estimates the individual percentile rank of a hypothetical "average" student in this group.
  • % (percent of students) scoring above the 75th NPR shows the percent of students in the group scoring in the top quarter nationally.
  • % (percent of students) scoring at or above the 50th NPR shows the percent of students in the group scoring in the top half nationally.
  • % (percent of students) scoring above the 25th NPR shows the percent of students in the group scoring in the top three-quarters nationally.
  • Mean Scaled Score estimates the group average scaled score for each grade level.

Percentile Ranks

A percentile rank is the percent of people in the norming sample who have scores less than or equal to a student's score. A student with a reading comprehension score at the 60th percentile scored equal to or better than 60 percent of the students in the norming sample. Stanford 9 is a nationally normed test. This means that the norm group is representative of a national cross-section of students. The norming sample for Stanford 9 included students from the northeastern, midwestern, southern, and western regions of the U.S. The sample also was representative of the nation in terms of ethnicity, urbanicity, socio-economic status, and students enrolled in private and Catholic schools. Since Stanford 9 is a nationally normed test, its norming sample was representative of the nation, but not necessarily of the state. The composition of this sample can be found in a Frequently Asked Questions (FAQ's) section of the California Department of Education web site (http://www.cde.ca.gov/cilbranch/sca).

NPR (National Percentile Rank) of the "Average" Student

For the STAR program, Stanford 9 reports national percentile ranks (NPRs) for individual students, but does not produce group level (e.g., school or district) percentile scores. A mean percentile rank for a group cannot be calculated from percentile ranks for individuals because they cannot be added or averaged across students. The national percentile rank of a hypothetical "average" student taken from any group can be approximated by finding the individual percentile rank of the mean NCE score for that group of students. A score based on NCEs (normal curve equivalents) places percentile scores onto a scale that divides the normal curve into equal units. NCE scores were developed to allow scores from different norm-referenced tests to be reported on a common scale, though NCE scores do not allow for direct comparisons across different norm-referenced tests. The mean NCE for a group of students is simply the average of the NCE scores for those students. This mean NCE is then reported in terms of an individual percentile that can be roughly interpreted as the 'NPR (national percentile rank) of the "average" student.'

% Scoring Above the 75th NPR, % Scoring At or Above the 50th NPR, and % Scoring Above the 25th NPR

These scores correspond to the percent of students in the school, district, county, or state scoring in the top quarter nationally; the percent of students scoring in the top half nationally; and the percent of students scoring in the top three-quarters nationally. The three levels used to create these group scores are the 75th, 50th, and 25th national percentiles, respectively. The percent of students scoring above each level is calculated by counting the number of students scoring at or above a particular level (e.g., 50th percentile) or above a particular level (e.g., 25th percentile and the 75th percentile), dividing by the total number of scores, and converting to a percentage. The percent scoring at or above the 50th percentile is the percent of students in this school, district, county, or state whose scores would place them in the top half of the students tested nationally. The percent scoring above the 75th percentile and above the 25th percentile are the percents of students in this group whose scores would place them in the top quarter and top three-quarters, respectively, of the students tested nationally.

Mean Scaled Score

Raw scores identify the number of items answered correctly on a subtest, but raw scores cannot be used to precisely identify differences in achievement. The problem is that all items are not "equal." Some items are more difficult, or they may cover different content. It also may be significant that different students respond correctly to different groups of items. To provide a more precise measure of the knowledge or skills tested, a scaled score is often calculated. A scaled score takes item differences into account. Through this calculation, an increase of one point at one place on the scale is described as being equal to a one-point increase anywhere else on the scale. Scaled scores are particularly useful for reporting changes over time. The Stanford Achievement Test Series provides results in terms of scaled scores for individual students and a mean or average scaled score for groups of students.


Linking Reports

In the upper left of each school report page, you will find the name of the state (California), county, school district, and school that corresponds to the report. Each of these underlined names provides a direct link to the report for the corresponding district and county, and for the state. Similarly, district reports are linked to the county and state reports, and county reports are linked to the state report. Click on any of these underlined links to display the report for that district or county, or for the state.


Printing Reports

These reports may be printed, but may not appear as you see them when printed in standard portrait format. Adjust your print setting to landscape (sideways) mode for better results.