The . . . . . . . . , though difficult to calculate, is the best measure of dispersion since it takes into consideration the whole data and the deviations are taken from the arithmetic mean.

The data which do not give any useful information rather confuse our mind are called

A. Raw data

B. Ungrouped data

C. Either A or B

D. None of the above

. . . . . . . . is based upon all the observations and it is suitable for further mathematical treatment

A. Geometric mean

B. Arithmetic mean

C. Median

D. None of the above

Alternate forms reliability is also known as

A. Parallel-forms reliability

B. Equivalent forms reliability

C. Comparable forms reliability

D. All of the above

. . . . . . . . enable the psychologists to obtain large quantities of data from people with minimum disturbance of their living routines and without elaborate laboratory equipment

A. Case histories

B. Tests

C. Surveys

D. None of the above