The number of students in the district view of the assessment widget can be different than the numbers displayed in the data extract view Assessment Annual Percentages.
The two views do not use the same logic, the same set of students, or even the same scores. The assessment widget uses a students best score and the data extract Assessment Annual Percentages uses any score for a given year. For these reasons trying to compare the charts is not recommended, however, if you keep their differences in mind, they will provide valuable data.
In the assessment widget, the students displayed are fixed by the student group parameters. The students in the group that took the requested test are the only ones displayed, and only a student's best overall score is used for calculations. For example, if the fifth grade students at Jefferson Middle School are the chosen filter group, and you want to review the MSP fifth grade math assessment, the student group is populated with only the fifth graders whose current year, predominant school was Jefferson.
In the data extract view, however, Assessment Annual Percentages is not based on any student group; it is based on students enrolled in a school. The students displayed vary for each school year and are determined by: 1) any student ever associated with the school (regardless of school year or predominance), and 2) any student who took the requested test in the given year. Using the example above, the extract includes any student who ever had an enrollment record at Jefferson, who also has a score for fifth grade MSP math in the current year. The extract does not consider best score, because inclusion in the results are based on whether or not a student took the test in the requested year. If a student took the same test in multiple years the student would be part of the count in multiple columns.