The careful scientist may test a hypothesis repeatedly in various ways. Following publication, other scientists may attempt to reproduce the results in their own experiments. Scientists are inherently cautious about accepting a novel hypothesis, so the more a result can be reproduced by different research teams, the more confidence scientists will have that it provides a correct explanation.
This situation can arise, for instance, when an industry funds research to test its products for health or safety. Most scientists resist these pressures, but whenever you are assessing a scientific study, it is always a good idea to note where the researchers obtained their funding. If a hypothesis survives repeated testing by numerous research teams and continues to predict experimental outcomes and observations accurately, it may be incorporated into a theory. A theory is a widely accepted, well-tested explanation of one or more cause-and-effect relationships that has been extensively validated by a great amount of research.
Whereas a hypothesis is a simple explanatory statement that may be disproven by a single experiment, a theory consolidates many related hypotheses that have been supported by a large body of data. Note that scientific use of the word theory differs from popular usage of the word. In everyday language when we say something is “just a theory,” we are suggesting it is a speculative idea without much substance.