{"main_topic":"education","sub_topic":"school_zones","topic":"school_attendance_zone_block_groups","key":"education/school_zones/school_attendance_zone_block_groups","version":"1.0.0","year_min":2027,"year_max":2027,"year_gaps":[],"update_frequency":"as zones change","detail_levels":["schools"],"default_detail":"schools","path_template":"education/school_attendance_zone_block_groups/year={year}/{detail}.parquet","grain":["year","district_code","school_code","grade_level","block_group_geoid"],"title":"School Attendance Zone Block Groups","summary":"Which 2020 census block groups each Georgia school attendance zone covers at each grade, with population, household and land-area shares.","description":"A crosswalk between Georgia public school attendance zones (the school_attendance_zones geometry topic) and 2020 census block groups. One row per school, grade and block group its zone covers at that grade. Weights are 2020 Census P.L. 94-171 block populations and households (occupied housing units), assigned to zones block by block exactly as in the tract crosswalk (school_attendance_zone_tracts): a block goes to the zone holding its interior point, or is split by area where a zone line or an unzoned gap crosses it. Use pct_of_block_group_households to roll block-group household data (ACS household tables) up to a zone, pct_of_block_group_population for person data. year is the school year the zones are in effect for (2027 = 2026-27). Zones are not official enrollment determinations; each zone's source and accuracy are on the zones topic.","explorer":false,"source":"School attendance zones (this platform's school_attendance_zones topic); U.S. Census Bureau 2020 Census P.L. 94-171 block populations and occupied housing units, TIGER/Line 2020 blocks, and TIGER/Line school district outlines.","source_url":"https://www.census.gov/programs-surveys/decennial-census/about/rdo/summary-files.html","endpoint":"/api/v1/education/school_attendance_zone_block_groups","columns":[{"name":"year","type":"integer","role":"year","nullable":false,"label":"Year","short_description":"","description":"School year the zones are in effect for, as its ending calendar year (2027 = 2026-27). The weights are 2020 census counts.","valid_values":null,"example":2027,"unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"district_code","type":"string","role":"fk_district","nullable":false,"label":"District Code","short_description":"","description":"GOSA district code (FK to the districts dimension).","valid_values":null,"example":"667","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"school_code","type":"string","role":"fk_school","nullable":false,"label":"School Code","short_description":"","description":"4-digit GOSA school code (composite FK to the schools dimension with district_code): the zone's school.","valid_values":null,"example":"0177","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"zone_level","type":"string","role":"categorical","nullable":false,"label":"Zone Level","short_description":"Elementary, middle or high zone.","description":"The level of the school's zone at this grade on the zones topic: elementary, middle or high. It follows from the grade and the school, so pin grade_level first.","valid_values":["elementary","middle","high"],"example":"elementary","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"grade_level","type":"string","role":"categorical","nullable":false,"label":"Grade Level","short_description":"Grade (k, 01-12).","description":"The grade the row's shares hold for (k, 01-12; pre-K is not zoned).","valid_values":["k","01","02","03","04","05","06","07","08","09","10","11","12"],"example":"k","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":true,"metric_component":null},{"name":"block_group_geoid","type":"string","role":"fk_block_group","nullable":false,"label":"Block Group GEOID","short_description":"","description":"12-digit 2020 census block group GEOID (FK to the block_groups dimension), as ACS 5-year tables publish.","valid_values":null,"example":"131210111001","unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"num_population","type":"integer","role":"metric","nullable":true,"label":"Number Population","short_description":"","description":"2020 census population of the block group living in the zone (whole persons).","valid_values":null,"example":812,"unit":"count","value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":"numerator"},{"name":"num_block_group_population","type":"integer","role":"metric","nullable":true,"label":"Number Block Group Population","short_description":"","description":"The block group's 2020 census population (all of its blocks), repeated on each of its rows: never add it across rows.","valid_values":null,"example":1532,"unit":"count","value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":"denominator"},{"name":"pct_of_block_group_population","type":"number","role":"metric","nullable":true,"label":"Percent of Block Group Population","short_description":"Share of the block group's 2020 population living in this zone.","description":"Share of the block group's 2020 population living in this zone at this grade (num_population / num_block_group_population).","valid_values":null,"example":0.53,"unit":"proportion","value_min":null,"value_max":null,"null_meaning":"The block group had no 2020 census population.","key_metric_grain_contributor":false,"metric_component":null},{"name":"pct_of_block_group_area","type":"number","role":"metric","nullable":true,"label":"Percent of Block Group Area","short_description":"","description":"Share of the block group's 2020 land area in this zone.","valid_values":null,"example":0.48,"unit":"proportion","value_min":null,"value_max":null,"null_meaning":"The block group has no land area (water only).","key_metric_grain_contributor":false,"metric_component":null},{"name":"pct_of_zone_population","type":"number","role":"metric","nullable":true,"label":"Percent of Zone Population","short_description":"","description":"Share of the zone's 2020 population at this grade living in this block group (adds to 1 over the zone's block groups).","valid_values":null,"example":0.04,"unit":"proportion","value_min":null,"value_max":null,"null_meaning":"The zone had no 2020 census population.","key_metric_grain_contributor":false,"metric_component":null},{"name":"num_households","type":"integer","role":"metric","nullable":true,"label":"Number Households","short_description":"","description":"2020 census households (occupied housing units, P.L. 94-171 H1_002N) of the block group in the zone, apportioned with the same block weights as the population (whole households).","valid_values":null,"example":301,"unit":"count","value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"num_block_group_households","type":"integer","role":"metric","nullable":true,"label":"Number Block Group Households","short_description":"","description":"The block group's 2020 households (all of its blocks; equals the block_groups dimension's households_2020), repeated on each of its rows: never add it across rows.","valid_values":null,"example":598,"unit":"count","value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null},{"name":"pct_of_block_group_households","type":"number","role":"metric","nullable":true,"label":"Percent of Block Group Households","short_description":"","description":"Share of the block group's 2020 households in this zone at this grade (num_households / num_block_group_households): the weight for household data.","valid_values":null,"example":0.503,"unit":"proportion","value_min":null,"value_max":null,"null_meaning":"The block group had no 2020 households.","key_metric_grain_contributor":false,"metric_component":null},{"name":"is_largest_zone_for_block_group","type":"boolean","role":"categorical","nullable":true,"label":"Is Largest Zone for Block Group","short_description":"","description":"True for the zone holding the most of the block group's 2020 population at this grade (ties: more land, then the lower district and school code): one row per block group and grade.","valid_values":null,"example":true,"unit":null,"value_min":null,"value_max":null,"null_meaning":null,"key_metric_grain_contributor":false,"metric_component":null}],"key_metric":"pct_of_block_group_population","usage":"Pin one grade_level: each row holds for that grade only, and a block group's zones at one grade split its people and households without overlap (across levels and districts). zone_level follows from the grade, so pin a grade of the level wanted. To roll a block-group household count (an ACS household table) up to a zone at that grade, multiply it by pct_of_block_group_households and add over the zone's rows; for a person count use pct_of_block_group_population. Never add the num_block_group_* totals across rows.","limitations":"Covers the districts whose zones were collected: a block group in a district without zones at a grade, or in a gap, has no rows there or rows whose shares add to less than 1 (gaps include withheld new schools' areas, placement areas and closed schools' former areas; see the zones topic's coverage table). Some zones predate an adopted boundary change (currency_status stale_known_changes on the zones topic) and carry that error here. Weights are the 2020 census: the share of a block group in each zone is frozen at April 2020, so it misses growth and new housing since. A block that a zone line or a gap's edge crosses is split by area, assuming its people and households are spread evenly over its land. Household counts carry the Census's disclosure-avoidance noise (a block can show households and no people), which shrinks as blocks are summed. A block counts toward the district whose current TIGER/Line outline holds its interior point. The same blocks and rules as the tract crosswalk (school_attendance_zone_tracts): summed to tracts, the people match it exactly. Rows are school rows.","null_semantics":{"suppressed_to_null":false,"zero_is_real":true},"available_years":[2027],"schema_hash":"58174ac48ecb9e3690fd18b0ed91a77df355be2469fcd64eead74aa8edfe53ce","tags":["education","school attendance zones","school_attendance_zone_block_groups"],"granularity_description":"One row per year, district_code, school_code, grade_level, block_group_geoid.","example_queries":[{"description":"Latest year (2027), schools detail","query":"SELECT * FROM school_attendance_zone_block_groups WHERE year = 2027 LIMIT 100"},{"description":"District 667 in 2027","query":"SELECT * FROM school_attendance_zone_block_groups WHERE district_code = '667' AND year = 2027 LIMIT 100"},{"description":"Filter by zone_level = elementary","query":"SELECT * FROM school_attendance_zone_block_groups WHERE zone_level = 'elementary' AND year = 2027 LIMIT 100"}],"foreign_keys":[{"column":"district_code","target_object":"districts","target_columns":["district_code"],"attribute_columns_added":["district_name","district_census_id","district_type"],"scope":"domain"},{"column":"school_code","target_object":"schools","target_columns":["district_code","school_code"],"attribute_columns_added":["school_name"],"scope":"domain"},{"column":"block_group_geoid","target_object":"block_groups","target_columns":["block_group_geoid"],"attribute_columns_added":["block_group_name"],"scope":"global"}],"filters":[{"param":"year","kind":"year_exact","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"year_min","kind":"year_range","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"year_max","kind":"year_range","type":"integer","multi_value":false,"enum_enforced":false,"values":null},{"param":"detail","kind":"detail","type":"string","multi_value":false,"enum_enforced":true,"values":["schools"],"default":"schools"},{"param":"district_code","kind":"foreign_key","column":"district_code","type":"string","multi_value":true,"enum_enforced":false,"values":null},{"param":"school_code","kind":"foreign_key","column":"school_code","type":"string","multi_value":true,"enum_enforced":false,"values":null},{"param":"block_group_geoid","kind":"foreign_key","column":"block_group_geoid","type":"string","multi_value":true,"enum_enforced":false,"values":null},{"param":"zone_level","kind":"categorical","column":"zone_level","type":"string","multi_value":true,"enum_enforced":true,"values":["elementary","middle","high"],"has_total":false,"total_value":null,"requires_single_value":false,"nullable":false,"null_filter_token":null},{"param":"grade_level","kind":"categorical","column":"grade_level","type":"string","multi_value":true,"enum_enforced":true,"values":["k","01","02","03","04","05","06","07","08","09","10","11","12"],"has_total":false,"total_value":null,"requires_single_value":true,"nullable":false,"null_filter_token":null},{"param":"is_largest_zone_for_block_group","kind":"categorical","column":"is_largest_zone_for_block_group","type":"boolean","multi_value":true,"enum_enforced":false,"values":null,"has_total":false,"total_value":null,"requires_single_value":false,"nullable":true,"null_filter_token":null},{"param":"district_type","kind":"dimension_attribute","dimension":"districts","column":"district_type","type":"string","multi_value":true,"enum_enforced":true,"values":["commission_charter","resa","standard","state_agency","state_charter","state_school","state_special"]},{"param":"school_level","kind":"dimension_attribute","dimension":"schools","column":"school_level","type":"string","multi_value":true,"enum_enforced":true,"values":["elementary","middle","high","k12","other"]},{"param":"locale","kind":"dimension_attribute","dimension":"schools","column":"locale","type":"string","multi_value":true,"enum_enforced":true,"values":["city","suburb","town","rural"]}],"filter_hints":[{"primary":"grade_level","dependent":"zone_level","note":"zone_level follows from grade_level: pin a grade of the level wanted."}],"non_additive":[{"column":"grade_level","reason":"Every grade's rows assign the same 2020 residents and households again (a block group's people are counted once per grade), so a count summed across grade_level counts them up to 13 times. Pin one grade."},{"column":"school_code","reason":"num_block_group_population and num_block_group_households are the block group's whole 2020 counts, repeated on each zone's row for it, so summed across schools or districts they count the block group again for every zone that touches it.","metrics":["num_block_group_population","num_block_group_households"]},{"column":"district_code","reason":"num_block_group_population and num_block_group_households are the block group's whole 2020 counts, repeated on each zone's row for it, so summed across schools or districts they count the block group again for every zone that touches it.","metrics":["num_block_group_population","num_block_group_households"]}],"value_implications":[],"values_endpoint":"/api/v1/education/school_attendance_zone_block_groups/values"}