RATING SCALE

Meaning:       

Rating is a term applied to express opinion or judgement regarding some situation, object of character. Opinions are usually expressed on a scale of values. Rating techniques are device by which such judgements may be quantified. Rating scale and score-card are the popular devices coming under the category of rating techniques.

Rating Scale :

            It is most commonly used in making appraisals of various sorts.

i)                    Teacher rating – for selection; evaluation and prediction.

ii)                  Personality rating – for various purposes.

iii)                Testing the validity of many objective instruments like paper-pencil inventories of personality.

iv)                School appraisal – including appraisal of course practices and programmes.

Rating scale consists of a limited number of items to which values on a scale have to be assigned. The value may be represented in the form of a number a point on a graduated line: or one among a series of worded descriptions. The construction of a rating scale calls for careful attention regarding the criteria of judgements to be used. The categories and different items used in the rating scale ought to be carefully defined, so that different people using the same scale may record their judgements as far as possible on the basis of the same ideas. It is usual to have 5 to 7 points on the scale for every item to be rated. An example of one of the items in a teacher rating scale is,

Excellent         very good        Average           Poor                 Very poor

                                                                                                                     

                                             

 

Clear in expressing his ideas                                                         Confused and muddled.

Limitations:

i)                    There is room for systematic errors in one’s rating through the influence of personal bias of the rater which is commonly referred to as “Halo effect”. In this, if more than one characteristic of a person is to be rated, rater (s) frequently carry over one generalized impression of the person from one rating to another.

ii)                  Generosity error occurs frequently when the rater develops a tendency to over estimate the desirable qualities of the rate whom he likes.

iii)                Constant error is the one where there is tendency on the part of the rater to see other as opposite to himself on a trait.

iv)                Sometimes raters have a tendency to play it safe and may mark all items in the centre that is the “average” category.

Means of reducing errors:

i)                    One of the ways of reducing constant error is to train the raters carefully and make them aware of the possibility of such bias in rating.

ii)                  Generosity error may be reduced by using relatively neutral descriptive terms for the scale positions rather than evaluative ones.

iii)                Halo-effect may be reduced or eliminated by having various rating of different persons made independently or by the same rather at different times without being aware that he is rating the same person again.

iv)                Tendency to place all the ratees at the central positions can be avoided by splitting the middle point into two above average and below average.

Reliability of the rating scale can be increased by not only careful training of refers but also by giving attention to the construction of the scale.