4 - Central Institute of Brackishwater Aquaculture

National Workshop-cum-Tra~nlng on Bi~informlltiCS and Information Management in Aquaculture
as bipolar adjectival phrases or words that are placed as anchor labels of a seven
category scale with no other numerical or verbal labels.
A Stapel Scale is a variation of the semantic-differential scale; however, each
item consists of just one word or phrase, on which respondents rate the attitude
object using a ten-item scale with just numerical labels.
6. Validity and Reliability
Validity is the extent to which a rating scale truly reflects the underlying
variable it is attempting to measure.
Content (Face) Validik: represents the extent to which the content of a
measurement scale seems to tap all relevant facets of an issue that can influence
respondents' attitudes.
Construct Validity assesses the nature of the underlying variable or construct
measured by the scale by examining the scales convergent and discrim~nant
validity.
Predictive Validity answers the question "How well does the attitude measure
provided by the scale predict some other variable or characteristic it is supposed
to influence"
Reliability measure how consistent or stable the ratings generated by the scale
are likely to be.
Test-Retest Reliability measures the stability of ratings over time and relies on
administering the scale to the same group of respondents at two different times.
Split-Half Reliability measures the degree of consistency across items within a
scale and can only be assessed for multiple-item scales.
8. Tests of Statistical Hypothesis:
Hypothesis is a declaratory statement that is testable. It is a statement about the
population that we wish to verify on the basis of available sample information.
It is a provisional answer to the research problem under study that is tested
empirically for its validity.
Usually, we test a Null-hypothesis against another alternative hypothesis. The
hypothesis, which is tested, is generally denoted as Ho ( Null Hypothesis) and
the other one, which gives a reverse statement, is denoted as HI (Alternative
Hypothesis).
Criteria for a good Hypothesis:
A good hypothesis should be
conceptually in clear terms;
should be testable;
formulated in specific terms;
related to available techniques, facts and theories.