A hypothesis is a likely explanation of a phenomenon or an observation. Scientists design careful experiments in order to validate the hypothesis. Such validation efforts require supporting evidence. Scientists carry out a number of experiments to check the validity of hypothesis. Data that supports the hypothesis helps us prove it and data that does not support the hypothesis, disproves it. In general, it is much easier to disprove a hypothesis than prove it. Any number of supporting evidence helps raise our confidence in the stated hypothesis, however, it takes only a single set of evidence against the hypothesis to disprove it. For example, if we hypothesize that plants grow better in presence of sunlight and carry out experiments, a single experiment where plants grown in dark setting shows better growth will disprove our hypothesis.
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