The Iowa Assessments allow growth to be measured by using vertically scaled (or articulated) scores, called standard scores. These scores plot out all students, regardless of grade level, on a continuum of student achievement. Standard scores describe a student’s location on an achievement continuum. Using standard scores, we can understand the growth students make from year to year. Des Moines Public Schools has established typical growth, which is the amount the average student increases in standard score points from year to year.
The gain in standard score needed to make at least typical growth on the Iowa Assessments varies by grade level. These values are listed in the chart to the left.
An example of growth on for four students from 4th to 5th grade is shown below. The standard score of the average 4th and 5th grade student are indicated on the standard score continuum. From the average standard score for each grade level, the typical growth the average student makes from year to year can be calculated.
All four students started at different places as 4th grade students on the standard score continuum. When they took the test again as 5th graders, the first student increased their standard score by 12 points, the second student by 16 points, the third by 14 points, and the forth by 9 points. Of the 4 students, two (the 2nd and 3rd student) made at least typical growth--increasing their standard scores by at least the typical growth of 14 points. Although the other 2 students demonstrated growth, they did not make typical growth, as they did not grow enough to keep pace with their peers.
