# Transparent Attribution of Contributions to Research: Aligning Guidelines to Real-Life Practices
## 2 Authors, Contributors and Acknowledees
In general, acknowledgments have increased in most disciplines, but there are wide disciplinary, cultural, linguistic and journal-specific differences [31; 32; 33; 34]. For example, of 2707 articles published in _Psychological Review_, 10% to 24% had acknowledgments in the first five decades of the 1900s, while this proportion exceeded 90% in the last three decades [31]. About 56% of 335,000 computer science articles in the CiteSeer database (published in 1990-2004) had acknowledgments [35]. Analyses of research articles in the hard and life sciences found that most had acknowledgments [32; 33; 34]. Studies in different disciplines reported that acknowledgments to editorial support were present in about 10% of the articles examined [31; 32; 33; 34]. An analysis of more than 1 million acknowledgments indexed in Web of Science in 2015 found that technical support was most often acknowledged by authors in the fields of chemistry, physics and engineering, while feedback from colleagues was most often acknowledged by social scientists [36]. Because there are no broadly accepted guidelines on which non-author contributions merit acknowledgment, it would be misguided to base inferences about the frequency or prevalence of these contributions on the numbers of explicit acknowledgments in samples of published research articles. Whether or not a paper has an Acknowledgments section and which contributions are listed or omitted depend largely on existing practices within disciplines, at journals and among researchers. The absence of an acknowledgment does not necessarily mean that the study did not benefit from important non-author support. There may have been additional contributions (by technicians, statisticians or editorial support professionals), but the authors may have preferred not to acknowledge them, or may not have been aware of any reason to do so. As for contributors, emerging evidence from surveys of professional authors' editors and translators shows that many (especially those working in disciplines other than the life sciences) do not consider acknowledgment necessary or even desirable, for a variety of reasons (see Section 3 and [37; 38]). At present, then, despite efforts to encourage appropriate credit and accountability for non-authors, a number of factors make openness about non-author contributions a concept that is not valued equally across the spectrum of research publishing actors:  
1. Compliance with institutional or editorial guidelines is essentially voluntary for byline authors. 2. Editorial policies vary among journals, publishers and disciplines, and byline authors are not always aware of these differences. 3. Institutions, journal editors and publishers seem mostly unable to verify or enforce compliance. 4. Non-author contributors have different expectations and practices, and may be unaware of editorial policies that encourage or require acknowledgment for contributions to the research or its written report. 5. Contributors such as statisticians--and especially authors' editors and translators--are often self-employed and serve as externally contracted consultants. Unlike byline authors, they are mostly free from pressure to publish because their career success does not depend on bibliometric performance indicators. So they may have little motivation to maximize the appearance of their name in the published research record, and little inclination to request public credit for their work if they believe their clients might find this issue awkward, intrusive or inappropriate. On the other hand, some may request or require acknowledgment for transparency or in the hope that their name will be noticed by potential clients.