5 Most Common SLO Growth Target Format Examples: May, 2016
5 Most Common SLO Growth Target Format Examples: May, 2016
Allowable formats (subject to evaluator approval):
- Half-the-Gap Formula:
Growth Target = ½ (100 – Pre-Assessment Score)
All students will increase their scores by one half the difference between 100 and the pre-assessment score.
Example: a student who received a rating of 50% on the pre-assessment would be expected to receive a rating of 75% on the post-assessment.
½ (100 – 50) = 25 pts.
Pre-Assessment Score: 50%
Growth Target:25 pts.
Post-Assessment target score: 75%
- Half-the-Gap Hybrid Formula:
For use when using the Half-the-Gap formula results in post-assessment score expectations that are significantly less rigorous that would be expected based on historical data with the assessment and/or teacher experience with the content. This is a two-part format.
Example: A pre-assessment for an AP Chemistry course results in no students scoring higher than 24%. The teacher expects most students to score at least 70% on the post-assessment in the Spring. Using half-the-gap formula would result in the expectation that student score no higher than 62%.
- Students with a pre-assessment score of less than 40% will have a growth target that will
result in post-assessment score of 70%
Growth Target = (70 – Pre-Assessment Score)
Ex: Pre-Assessment score of 20%
Growth target = (70 – 20)
Growth target = 50 points (target score: 20 + 50 = 70%)
- Students with a Pre-Assessment score of 40% or higher: use half-the-gap formula:
Growth Target = ½(100 – Pre-Assessment Score)
Ex: Pre-Assessment score of 44%
Growth target = ½ (100 – 44)
Growth target = 28 points (target score: 44 + 28 = 72%)
3. District-Set for instrument:
All students with same pre-assessment score will have the same growth target, across the district.
Example: District sets growth targets for kindergarteners using Aimsweb
4. Test-Provided:
Test vendor sets growth targets based on pre-assessment scores
Example: NWEA set Fall to Spring math growth targets for each student in Grade 6
5. PGR:
SLO rating determined by the percentage of the gap reduced between the class’ mean Pre-Assessment score and the maximum score set.
Step 1: Determine Mean Performance Gap (Difference between the maximum score and the class’ mean Pre-Assessment score.)
Example: Mean average Pre-Assessment score for all students in the course: 54 pts.
Step 2: Determine the Mean Performance Growth (Difference between class’ mean Post-Assessment score and the class’ mean Pre-Assessment score)
Example: Mean average Post-Assessment score for all students in the course: 84%
84 – 54 = 30 pt. (mean performance growth)
Step 3: Determine Percent Gap Reduction ((mean performance growth) divided by (mean performance gap) multiplied by 100))
Example: (30 ÷ 46) = 0.65 x 100 = 65% gap reduction (SLO rating – 3.0; see chart below)
PGR SLO Rating Scale:
Mean Gap Reduction / Rating75% or higher / 4
50-74.4% / 3
25-49.4% / 2
25.4% or less / 1
*District may want to refine the rating chart using tenths