The answer is "Type of play; no play".
Type of play is the independent variable.
A variable is something you're attempting to measure. It tends to be for all intents and purposes anything, for example, objects, measures of time, emotions, occasions, or thoughts.
The independent variable is the variable whose change isn't influenced by some other variable in the trial. Either the researcher needs to change the free factor or it changes without anyone else; nothing else in the experiment influences or changes it.
No play is the control group.
Control group, the standard to which examinations are made in an experiment. Numerous experiments are intended to incorporate a control gathering and at least one trial gatherings; truth be told, a few researchers hold the term analyze for contemplate outlines that incorporate a control gathering. In a perfect world, the control gathering and the exploratory gatherings are indistinguishable inside and out with the exception of that the test bunches are subjected to medicines or interventions accepted to affect the result of intrigue while the control amass isn't.