3. HYPOTHESIS
Any assumption that the researcher
makes on the probable direction of the
result that might be obtained on
completion of the research process is
termed as a HYPOTHESIS
Hypothesis testing is a process of
choosing
Between competing hypotheses about
a probability distribution , based on
observed data from the distribution.
4. Concept Of Hypothesis
Null hypothesis
An assertion that a parameter in a
statistical model takes a particular
value , and is assumed true until
experiment evidence suggest .
Alternative hypothesis
It express the way in which the value of a
parameter may deviate from that
specified in a null hypothesis, and is
assumed true when the experiment
evidence suggests that the null
hypothesis is false.
5. ONE TAILED TEST
A hypothesis test in which the
population parameter is known to fall
either left or right of center of the
sampling distribution is called one
tailed test.
6. TWO TAILED TEST
A statistical test in which the critical area of
a distribution is two sided and tests whether
a sample is either greater than or less than a
certain range of values.
7. Types Of Error.
The following table gives an idea about
the Type I and Type II Errors.
Accept HₒAccept Hₒ Reject HₒReject Hₒ
H is trueₒH is trueₒ
H is falseₒH is falseₒ
No ErrorNo Error Type I ErrorType I Error
Type II ErrorType II Error No ErrorNo Error
9. CONCLUSION
In practice , we should use a one
tailed test only when we have a good
reason to expect that the difference
will be in a particular direction. A two
tailed test is more conservative than a
one tailed test because a two- tailed
test takes a more extreme test statistic
to reject the null hypothesis.
