関連ワード:  what is a control variable in a research study    what is a independent variable in a research study    what is the role of a control variable in a research study    what is the purpose of control variables in a research study    what is an independent variable in a scientific study    what is an independent variable in a research paper    what is the purpose of an independent variable in a research study    what is the role of an independent variable in a research study    what is control variable in research    what is a control.variable  
結果 : what is a control variable in a research study