Advantages of Rating Scale:
1. A simple form of rating scale is commonly employed in judging contests of various kinds such as speaking and music competitions.
2. Rating Scales have been put to extensive uses in the field of rating teaching and teachers. This process extends to the selection of teachers and the prediction of teaching success.
3. Rating Scales are also used for testing the validity of many objective instruments like paper-pencil inventories of personality.
4. These scales are also employed for school appraisal including appraisal of courses, practices and programmes.
5. The rating scales are advantageous in several other ways. They are –
i) helpful in writing reports to parents.
ii) helpful in filling out admission blanks for colleges.
iii) helpful in filling out student needs.
iv) helpful in recommendations to employers.
v) helpful in supplementing other sources of understanding~about the child.
vi) helpful in their stimulating effect upon the individuals who are rated.
Limitations of Rating Scale:
1. People differ markedly in their ability to make ratings.
2. People differ in their reliability as subjects for ratings.
3. Immediate emotional reactions affect ratings.
4. Self-ratings tend to be too high on desirable traits and too low on undesirable traits.
5. Raters are frequently unable to justify ratings or are apt to give absurd rationalizations.
6. Generosity Error –The raters would not like to run down their own people by giving them low ratings. The result is that high ratings are given in almost all cases. The raters are also inclined to be unduly generous in rating aspects which they have had no opportunity to observe.
7. The Halo Error -It is difficult for rater to get rid of the halo effect which causes him to carry qualitative judgement from one aspect to another. Halo effect appears frequently when the rater has to rate a number of factors on some of which he has no evidence for judgement.
8. The Error of Central Tendency –There is a tendency in some observers to rate most of the raters near the mid points of the scale.
9. Stringency Error -The opposite of generosity error may be called stringency error. Some raters are so cautions and hesitant that they have a tendency to rate are all individuals low.
10. The Logical Error -It is difficult to convey to the rater just what quality one wishes him to evaluate. An adjective or adverb may have no universal meaning.