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accurate. All it means is consistency in drawing conclusions. For
example, the weight of a person with actual weight of 65 kg shown
in a weighing machine was 70 kg when he weighed for the first
time. If the reading on the machine consistently shows 70 kg when
the weight of the same person is weighed several times at that time
itself, then we can say that the weighing machine is reliable.
Stability and non-variability are the key components of ◆ Stability and
reliability. Stability deals with stable results in repeated consistency
measurements conducted on the same object. Non-variability
deals with consistency in the results obtained from different
investigators and samples.
b. Validity

The validity of a measurement instrument indicates the extent to
which the instrument or scale tests or measures what it is supposed ◆ Utility of instrument
to measure. Validity needs to be checked for abstract concepts
such as attitude, satisfaction, motivation etc. rather than physical
properties like weight, length, width, height etc.. For example, if a
reward system to measure the performance of a salesman is based
solely on sales figures regardless of territory, the reward system
may not be valid if territories do impact sales.

There are four types of validity that are:

◆ Face validity
◆ Content validity
◆ Criterion validity

◆ Construct validity
Face validity
In face validity, the researcher focuses only on the outer surface ◆ Focus on outer
of the tool, may it be an interview schedule or a questionnaire. surface
The main contents are not focused just like a person focusing only
on the style, colour, and physical appearance while buying a car
rather than on its engine and performance. Therefore, it becomes
a subjective assessment.

Content validity
It indicates the extent to which coverage of the topics being
studied is provided. In content validity the researcher evaluates
the main content of the tool for its appropriateness, accuracy and ◆ Coverage of topic
completeness. If the instrument contains a representative sample
of the universe, the content validity is good. Its determination is
primarily judgemental and intuitive. It can also be determined by
using a panel of persons who shall judge how well the measuring
instrument meets the standards, but there is no numerical way to
express it. All aspects of the research tool are considered to check
for content validity.

SGOU - SLM - MCom Research Methodology 111