From the U.S. Dept. of HHS Office of Research Integrity:
(a) Fabrication is making up data or results and recording or reporting them.
(b) Falsification is manipulating research materials, equipment, or processes, or changing or omitting data or results such that the research is not accurately represented in the research record.
(c) Plagiarism is the appropriation of another person's ideas, processes, results, or words without giving appropriate credit.
** Note: Self-plagiarism is NOT considered research misconduct in accordance to 42 CFR 93.