The process is called peer review. Scientists are obligated to publish their research in scientific journals. The number of publications a scientist has will impact his or her career path and advancement. When a scientist finishes a study, he/she and his/her collaborators will write a manuscript outlining and discussing the results of the study. This manuscript will be sent to a journal for publishing. There are usually several journals publishing within each field, with some more prestigious than others, as indicated by an impact factor. Journals such as Science and Nature have the highest impact factor as they have the greatest readership. The editor of the journal will send the manuscript off to other scientists working in the same field, and will ask them to 'peer review' the manuscript to determine whether the paper deserves publication, whether it requires corrections, or whether is should be rejected outright. Ideally, papers should be rejected because of bad science, and not because the results contradict previous studies or current scientific theory.
