Objectivity:

Objectivity means freedom from bias. A test should yield a clear  score value for each performance, the score being independent of the personal judgment  of the  score. 

Economy:

Tests that  can be  given  in  short period of time are likely to gain  the cooperation of the subject and to conserve the  time of  those involved in test administration. The matter of expense is  also a significant factor. vi) Practicability Simplicity of administration, scoring and interpretation are important factors  in selecting test. 

Interest:

Both the researcher  and subjects should enjoy the experience of data collection. The  investigator gains cooperation of subjects  if responding  to  an instrument is interesting and enjoyable, and the measuring tool may  not yield useful results if they  are dull or  seem silly (foolish).