Data Review for Fall 2020 Elementary School Boundary Process (Phase 2)

Community Engagement  |  Background  |  Objectives  |  TimelineFAQsResources | Staff Responses

In Spring 2020, APS is inviting community members to review data that will be used in the Fall 2020 Elementary School Boundary Process. This review of data by Planning Unit—the geographic building blocks APS uses to establish school attendance zones— will help ensure that the final data reflects what you know about your neighborhood, is accurate, complete and ready for use in adjusting boundaries across neighborhood elementary schools this fall.

May 19 Community Online Information Session

Community Engagement

This questionnaire allows APS staff to gather community input from stakeholders based on their knowledge of their neighborhoods. Staff will review all input and make any necessary revisions to the Planning Unit data. A summary of community input and the final planning unit data will be posted on the APS Engage website in August 2020.

Community engagement opportunities are available from May 12 through June 5, 2020 (details below), with an online Community Questionnaire serving as the primary method for gathering input. APS strives to be transparent throughout this process and appreciates the input from community members who participate in this data review.In this data review process, APS asks community members to do the following:

  • Review Planning Unit data using their knowledge of their neighborhoods (Planning Units are the geographic building blocks used to define attendance boundaries for neighborhood schools)
  • Identify any items in a specific Planning Unit that APS should consider
  • If stakeholders want to express a preference on methodology, consider the two alternative approaches that APS could use for the Planning Unit projections methodology and share input with staff

The following are the information resources for community members to review and share their input in this process:

Community Engagement Activities


As APS grows to 30,000 students in 2021, we are using a countywide approach to the Fall 2020 boundary process that takes the needs of all students into account. Elementary Planning for 2021 has four phases, with all changes taking effect in August 2021:


diagram of elementary school planning process described below

  • In Spring 2020, APS is conducting the Phase 2 review of data for use in the Fall 2020 boundary process, with final data to be published in August 2020.
  • This data review is an important first step for the boundary process. By sharing the data now and conducting this review early with stakeholders before developing boundary scenarios, staff can gather valuable input from residents who know their neighborhoods.
  • The Planning Unit data in this review are based on a special enrollment projection done in early 2020, which is different from the 10-year enrollment projections released in Fall 2019.
  • In Fall 2020, APS will implement the Phase 3 boundary process and adjust boundaries across elementary schools. This process will develop attendance zones for the new neighborhood elementary schools at the Key (2300 Key Blvd.) and Reed (1644 N. McKinley Rd.) sites, and a new neighborhood attendance zone around ASFS (1501 N. Lincoln St.), to take effect in August 2021

Data Review Objectives

This data review seeks to prepare APS for the Fall 2020 boundary process as follows:

  • Be transparent in sharing Planning Unit data with the community as the first step in preparing for this boundary process
  • Conduct a careful and critical examination with stakeholders of the Planning Unit data that will be used in this  boundary process
  • Review input received and ensure data is accurate, complete and ready to use for boundary adjustments
  • Publish the final Planning Unit data in August 2020 that will be used in the fall boundary process (Phase 3)

Data Review Timeline

February–April 2020 Internal preparations for data review process
Late April Share data table and gather feedback from early reviewers, including representatives from the Advisory Council on School Facilities and Capital Programs (FAC) and the County Council of PTAs (CCPTA)
May 12–June 5, 2020 Community engagement for Phase 2 Data Review process, which includes community information sessions and a community questionnaire to gather community input related to Planning Unit data
June–August 2020 Internal analysis of input and preparation with school administrators and internal cross-departmental team for the upcoming boundary process
August 2020 Publish final Planning Unit data to be used in fall boundary process
Fall 2020 Elementary School Boundary Process (Phase 3)

Frequently Asked Questions

Planning Units

Q1: Will planning unit data be updated in the fall before/during phase 3 with sept 30th, 2020 enrollment info? 

  • A1: The Planning Unit projections for Grade K to 5 will not be updated in Fall 2020 with September 30, 2020 enrollment counts. The reason for this is timing:  Phase 3, which will develop boundaries for neighborhood elementary schools for 2021-22​, needs to start in Fall 2020 and updating projections will delay that process. In addition, in Fall 2020, the staff that works on enrollment projections will be focused on producing a new round of 10-year enrollment projections which will use September 30, 2020 enrollment.

Q2: Will planning unit splits be considered? 

  • Splitting planning units is not a part of this process at this time. The only planning unit split we may consider would be for single new development. We plan to review planning units in about two years; following a five-year cycle.

Projections Methodology

Q1: What is assumed for the number of Kindergarten students that will not attend their neighborhood school and attend an option school/program? 

  • A1:  The Spring 2020 planning unit projections assume that 506 Kindergarten students will attend an elementary option school/program in each of the years between 2020-21 to 2023-24.  These 506 Kindergarten students are not counted among the Grade K students that are projected to attend their neighborhood school in those years.  The assumption of 506 Kindergarten students who attend option schools/programs, references the “Spring 1-Year Projections Update for the 2020-21 School Year” document that can be found at this link,  The 2020-21 Spring Update, which is used for staffing and budgeting purposes for each school and program, estimates the following number of Kindergarten students at following schools:  Arlington Traditional with 96 K students, Campbell with 72 K students, Claremont with 144 K students, Key with 144 K students, and the Montessori Public School of Arlington with 50 K students.

Q2: Why does the data only go to 2024? What not look at data through 2025 or 2026?

  • A2: An initial run of the planning unit projections was for the years 2020 to 2023. The reason for projecting out four years was because in this approach, the projections rely mostly on information from students that already attend APS as of September 30, 2019. For example, by projecting out four years a current Grade 4 student will be in Grade 5 in 2020, a current Grade 3 student will be in Grade 4 in 2020, etc. In addition, in each projection year, assumptions must be made about future incoming kindergarten students for 2020 through 2023; they are students not in the APS system yet. A benefit of projecting out four years is that APS does have live birth records, courtesy of ACG, for the years 2015 to 2018. A certain percentage of 2015 births will enroll as APS kindergarten students in 2020, a percentage of 2016 births will be future kindergarteners in 2021, a percentage of 2017 births will be future kindergarteners in 2022, and a percentage of 2018 births will be future kindergarteners in 2023. As of May 7, 2020, neither ACG or The Virginia Department of Health’s Division of Health Statistics have the number of actual births for Arlington County parents that occurred in 2019. Upon request from Advisory Council on School Facilities and Capital Programs (FAC) and other members of the community, the planning unit elementary projections will project out one extra year to 2024. The 2019 births that will inform the 2024 kindergarten students was forecasted by ACG and RLS Demographics, a consultant who has worked with ACG on its Cohort Component Model to forecast births, and provided to APS on September 30, 2019. Assumptions going out further than 2024 provide uncertainty with the data.

Q3: For planning units with a large number of military families, numbers of enrolled kids change based on the movement of those families. Have you looked at enrollment projections for schools that have mobile populations and factored that into the equation for neighborhood school boundaries?

  • A3: Military participation is not a required question upon registration and APS does not have consistent information on military participation from our families. We do calculate cohort transition rates, K to 5: To “age” students from one grade to another—from one year to the next year—a three-year average county-wide cohort transition rate was calculated for Grades K to 1, 1 to 2, 2 to 3, 3 to 4, and 4 to 5. The three-year average used historical Sept. 30 enrollment from 2017, 2018, and 2019. These rates were applied to elementary cohorts at the planning unit level as they “age” to the next grade in the next school year.

Q4: Is there a big difference in the number of students using the different methodology approaches?

  • A4: There are slight differences – see columns A-K in the Planning Unit Data Table. APS staff is asking the community to weigh in on which methodology approach is more reasonable. The Planning Unit Data Table has elementary projections in which Kindergarten students likely to attend their neighborhood school were calculated according to a planning unit’s relative kindergarten population size (Approach 1–similar to the 2018 approach); OR based on a planning unit’s half mile proximity to an option school (Approach 2). Note that Approach 2 takes into consideration the fact that two option/school programs will relocate, thus planning units close to the relocated Immersion and Arlington Traditional elementary schools will have higher percentages of kindergarten students attending an option school.
  • A4: Background: In the Fall 2018 elementary school boundary process, the community and decision makers questioned the approach of estimating the number of kindergarten students who would attend an option school based on the planning unit’s relative population size (approach 1). The rationale for questioning this approach is that it did not account for the influence an option school’s location is likely to have on a parent’s decision to enroll their child in an option school. For example, it was asserted that a parent is more likely to enroll their kindergarten student in an option school if they live close to that option school. By extension, the percentage of kindergarten student’s likely to attend their neighborhood school should be lower for planning units that are in proximity to an option school, since a high percentage of kindergarten students are enrolled in an option school. In order to address these concerns expressed in 2018 regarding the estimation of future kindergarten students by planning units likely to attend their neighborhood school, In order to address these concerns expressed in 2018 regarding approach 1, we are asking the community to weigh in on which approach is more reasonable.


Q1: Where does your housing information come from, and why are you asking the community to verify it?

  • A1: See “Data Sources” on pg. 2 of methodology document. Housing Unit Forecast from Arlington County Government (ACG) from September 2019 and updated with ACG residential construction status information from March 2020, see Table 2. This data includes a timeline of when residential construction projects are forecasted by ACG to be completed and habitable, each project’s residential type, number of net new units, and affordability levels. This information helps APS estimate the number of new students and the year that a given housing development will add students to neighborhood schools.
  • We work closely with the ACG for any updates to the data provided. We appreciate the community looking at it closely as community members know their neighborhoods best and know quite a bit about development happening in their neighborhoods. We appreciate a second look.

Q2: Are the Student Generation Rates updated annually? How are they calculated for different types of housing? 

  • A2: The student generation rates are calculated each year and use a yearly updated housing unit snapshot made possible to APS through a data-sharing agreement with Arlington County Government (ACG).  Each year APS matches the most current September 30 student enrollment counts by address to the yearly updated housing inventory in the County from ACG.  The yearly updated housing snapshot, known as Master Housing Unit Database (MHUD) includes housing type, number of units, details on the number of Committed Affordable Units (CAFs), and affordability classification for each complex (CAF only, Market Rate, or Mixed), and the presence of an approved Accessory Dwelling Unit (ADU) on a  residential parcel. The Student Generation Rate is the mathematical representation of the relationship between the number of existing housing units in Arlington County and the number of students—by housing unit type and affordability designation—enrolled at APS on September 30 for a given year.  This rate is calculated for every neighborhood school boundary at the elementary, middle, and high school levels. A copy of the Students Generation Rate tables for Fall 2019, 2018, and 2017 can be found at these links:

Q3: How are the Student Generation Rates applied? 

  • A3: When the ACG staff provides the housing unit forecast, each forecasted residential development is matched to its corresponding planning unit, neighborhood elementary boundary, neighborhood middle school boundary, and neighborhood high school boundary.  With the neighborhood boundary information known and the housing development type (townhouse or garden for example) and affordability level (market-rate, mixed-income, or all affordable) from ACG noted, the Student Generation Rate table is used, see (see Attachment C).  The relevant neighborhood boundary, housing type, and affordability level are cross-referenced on a table to get each housing project’s unique Student Generation Rate.  For example, if a housing project is in the (a) Barrett Elementary boundary, the housing type of the project is (b) Garden multi-family, and the housing project’s affordability level is (c) mixed-income, then relevant student generation on the table (see Attachment C) will be 0.278.  If, for example, a neighborhood boundary does not have a housing type Student Generation Rate, then the default is to use the county-wide student generation rate for that housing type and affordability-level.

Q4: How will you use the community’s input from the questionnaire that identifies some difference in reported development projects?

  • A4: APS staff will verify the community’s input against developments in ACG’s data. Where there are differences, we’ll do further work to make sure our information is the most accurate. Final data will reflect identified and verified changes.

Staff Responses to Inquiries Received from Community Members.pdf


Table of Kindergarten Students by Planning Unit 2017, 2018, 2019

Superintendent’s 2020 Annual Update

Planning Units Intersect Half Mile Radius From Option School Map | Planning Units Half Mile of Option School Excel Spreadsheet