"control experiment" meaning in English

{
  "forms": [
    {
      "form": "control experiments",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "control experiment (plural control experiments)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
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        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
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          "source": "w"
        }
      ],
      "glosses": [
        "A parallel experiment designed to replicate the main experiment in every way, except in respect of the one variable that is being tested, so as isolate the effect of that variable; for example, an experiment in which subjects are given a placebo instead of an active drug, intended to check that any observed benefits of the drug derive from the drug itself and not from other factors involved in its administration."
      ],
      "id": "en-control_experiment-en-noun-n9adma7F"
    }
  ],
  "word": "control experiment"
}

{
  "forms": [
    {
      "form": "control experiments",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "control experiment (plural control experiments)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns"
      ],
      "glosses": [
        "A parallel experiment designed to replicate the main experiment in every way, except in respect of the one variable that is being tested, so as isolate the effect of that variable; for example, an experiment in which subjects are given a placebo instead of an active drug, intended to check that any observed benefits of the drug derive from the drug itself and not from other factors involved in its administration."
      ]
    }
  ],
  "word": "control experiment"
}