"control variable" meaning in English

{
  "forms": [
    {
      "form": "control variables",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "control variable (plural control variables)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Sciences",
          "orig": "en:Sciences",
          "parents": [
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "examples": [
        {
          "text": "There are different ways of analysing equations and I prefer to look at elements involved as often either fixed or control variables."
        }
      ],
      "glosses": [
        "A factor that is held constant in a series of experiments in which other factors are varied"
      ],
      "id": "en-control_variable-en-noun-p231D5aq",
      "links": [
        [
          "sciences",
          "sciences"
        ],
        [
          "factor",
          "factor"
        ],
        [
          "constant",
          "constant"
        ],
        [
          "series",
          "series"
        ],
        [
          "experiment",
          "experiment"
        ]
      ],
      "raw_glosses": [
        "(sciences) A factor that is held constant in a series of experiments in which other factors are varied"
      ],
      "related": [
        {
          "english": "also known as controlled variable.",
          "word": "independent variable"
        },
        {
          "word": "dependent variable"
        }
      ],
      "topics": [
        "sciences"
      ],
      "translations": [
        {
          "code": "eo",
          "lang": "Esperanto",
          "sense": "factor",
          "word": "iteracinombrilo"
        },
        {
          "code": "ml",
          "lang": "Malayalam",
          "roman": "niyantraṇacaraṁ",
          "sense": "factor",
          "word": "നിയന്ത്രണചരം"
        }
      ]
    }
  ],
  "word": "control variable"
}

{
  "forms": [
    {
      "form": "control variables",
      "tags": [
        "plural"
      ]
    }
  ],
  "head_templates": [
    {
      "args": {},
      "expansion": "control variable (plural control variables)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "related": [
    {
      "english": "also known as controlled variable.",
      "word": "independent variable"
    },
    {
      "word": "dependent variable"
    }
  ],
  "senses": [
    {
      "categories": [
        "English countable nouns",
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "en:Sciences"
      ],
      "examples": [
        {
          "text": "There are different ways of analysing equations and I prefer to look at elements involved as often either fixed or control variables."
        }
      ],
      "glosses": [
        "A factor that is held constant in a series of experiments in which other factors are varied"
      ],
      "links": [
        [
          "sciences",
          "sciences"
        ],
        [
          "factor",
          "factor"
        ],
        [
          "constant",
          "constant"
        ],
        [
          "series",
          "series"
        ],
        [
          "experiment",
          "experiment"
        ]
      ],
      "raw_glosses": [
        "(sciences) A factor that is held constant in a series of experiments in which other factors are varied"
      ],
      "topics": [
        "sciences"
      ]
    }
  ],
  "translations": [
    {
      "code": "eo",
      "lang": "Esperanto",
      "sense": "factor",
      "word": "iteracinombrilo"
    },
    {
      "code": "ml",
      "lang": "Malayalam",
      "roman": "niyantraṇacaraṁ",
      "sense": "factor",
      "word": "നിയന്ത്രണചരം"
    }
  ],
  "word": "control variable"
}