{"id":"https://openalex.org/C153240184","wikidata":"https://www.wikidata.org/wiki/Q3243772","display_name":"Control variable","level":2,"description":"experimental element which is constant and unchanged.","works_count":20486,"cited_by_count":164446,"summary_stats":null,"ids":{"openalex":"https://openalex.org/C153240184","wikidata":"https://www.wikidata.org/wiki/Q3243772","mag":null,"wikipedia":"https://en.wikipedia.org/wiki/control_variable","umls_aui":null,"umls_cui":null},"image_url":null,"image_thumbnail_url":null,"international":{},"ancestors":null,"related_concepts":null,"counts_by_year":null,"works_api_url":"https://api.openalex.org/works?filter=concepts.id:153240184","updated_date":"2026-07-29T04:02:35","created_date":"2016-06-24T00:00:00"}