Based on a Regression Analysis with the percentage of ECD and CWD children at the school as control variables, the expected score describes the predicted average percentage of students deemed proficient on the Reading Language Arts section of the standardized test for the 2018-19 school year.
The actual score is based on the reported scores for this school as reported by the US Dept of Education. Below you can see how this score was reported in its raw form. Sometimes a range is reported, in which case we take the average of the range. For the most part, if there is a range, the delta is 4 points, so by taking the average we are at most 2 points off the actual score for the school.
This table shows the data as it was extracted from a spreadsheet provided by the US Department of Education. "LE" means less than or equal to, "LT" is less than, "GT" is greater than, and "GE" is greater than or equal to. Typically these prefixes are associated with small populations of students. Sometimes you will see a date as an attribute, this is because sometimes excel interprets a range of values as a date. So "19-Nov" is equivalent to "11-19".
This data allows us to calculate the percentage of kids classified as Economically disadvantaged (ECD) and Children with Disabilites (CWD). We use this data in a regression analysis that predicts expected test scores. The expected test score is then subtracted from the actual test scores, and schools for each state are then ranked by the difference between each school's expected and actual scores. The highest ranked schools have the largest difference, indicating the school is outperforming expectations to the highest degree.