A general or default position that a researcher tests (and attempts to reject) in an experiment. The null hypothesis,
H
0
, is an essential part of a research design, and usually proposes that sample
Observation
s result purely from chance. The null hypothesis can never be proven; data can
reject it
or
fail to reject it
only. If a null hypothesis is rejected, an
Alternative Hypothesis
,
H
1
(or
H
a
) is accepted.