In at least 150 words, justify the need for a control in an experiment. Use complete sentences. Write your answer in the essay box below.

You need to include a control group that is identical to the treatment group in every way except that it does not receive the experimental treatment. Without a control group, you can't know whether it was the treatment or some other variable that caused the outcome of the experiment.

The control group consists of elements that present exactly the same characteristics of the experimental group, except for the variable applied to the latter. This group of scientific control enables the experimental study of one variable at a time, and it is an essential part of the scientific method. In a controlled experiment, two identical experiments are carried out: in one of them, the treatment or tested factor (experimental group) is applied; whereas in the other group (control), the tested factor is not applied.

The Parson's flat or apartment is bigger than Winston's but very messy, Dishes are piled in the sink and the children's toys, books, and clothes are scattered everywhere.

TRUE

Explanation:

'The Parsons' flat was bigger than Winston's, and dingy in a different way. Everything had a battered, trampled-on look, as though the place had just been visited by some large violent animal. Games impedimenta--hockey-sticks, boxing-gloves, a burst football, a pair of sweaty shorts turned inside out--lay all over the floor, and on the table there was a litter of dirty dishes and dog-eared exercise-books. On the walls were scarlet banners of the Youth League and the Spies, and a full-sized poster of Big Brother. There was the usual boiled-cabbage smell, common to the whole building, but it was shot through by a sharper reek of sweat, which--one knew this at the first sniff, though it was hard to say how--was the sweat of some person not present at the moment. In another room someone with a comb and a piece of toilet paper was trying to keep tune with the military music which was still issuing from the telescreen.'