professionals are often selling opinions. Corporations can pay experts to support products directly or indirectly via conferences. Psychologists can make money by repeatedly acting as an expert witness in custody proceedings for the same law firms. Forms The U.S. National Science Foundation defines three types of research misconduct: fabrication, falsification, and plagiarism. Fabrication is making up results and recording or reporting them. This is sometimes referred to as "drylabbing". A more minor form of fabrication is where references are included to give arguments the appearance of widespread acceptance, but are actually fake, or do not support the argument. 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. Plagiarism is the appropriation of another person's ideas, processes, results, or words without giving appropriate credit. One form is the appropriation of the ideas and results of others, and publishing as to make it appear the author had performed all the work under which the data was obtained. A subset is citation plagiarism – willful or negligent failure to appropriately credit other or prior discoverers, so as to give an improper impression of priority. This is also known as, "citation amnesia", the "disregard syndrome" and "bibliographic negligence". Arguably, this is the most common type of scientific misconduct. Sometimes it is difficult to guess whether authors intentionally ignored a highly relevant cite or lacked knowledge of the prior work. Discovery credit can also be inadvertently reassigned from the original discoverer to a better-known researcher. This is a special case of the Matthew effect. Plagiarism-fabrication – the act of taking an unrelated figure from an unrelated publication and reproducing it exactly in a new publication, claiming that it represents new data. Self-plagiarism – or multiple publication of the same content with different titles or in different journals is sometimes also considered misconduct; scientific journals explicitly ask authors not to do this. It is referred to as "salami" (i.e. many identical slices) in the jargon of medical journal editors. According to some editors this includes publishing the same article in a different language. Other types of research misconduct are also recognized: Ghostwriting – the phenomenon where someone other than the named author(s) makes a major contribution. Typically, this is done to mask contributions from authors with a conflict of interest. Conversely, research misconduct is not limited to not