Debates concerning the status, relevance, and ethical stance of artifact collectors, and whether archaeologists and other heritage professionals should seek to engage them, are present in most parts of the world. The Advances in Archaeological Practice special issue “Professional–Collector Collaboration: Moving beyond Debate to Best Practice,” published in February 2022, presents examples of engagement and dilemmas that such activities pose for archaeologists within the context of the United States (Pitblado et al. Reference Pitblado, Rowe, Schroeder, Thomas and Wessman2022). In this special issue, we expand the discussion to the global level, with articles from Europe, Central and South America, and Oceania.

Articles in the earlier issue discussed at length the collectors with whom engagements occurred, emphasizing that there is a spectrum of responsibility and responsiveness in avocational practices. As discussed elsewhere (e.g., Pitblado Reference Pitblado2014:387; Thomas Reference Thomas2016:143), this continuum is often conceptualized as featuring so-called professional looters (those who illegally remove artifacts for profit and feed the antiquities market) at one extreme, and fully responsible hobbyists who share information with archaeologists and the authorities and follow best practices at the other.

As the archaeological profession strives for a more open and democratic approach that not only acknowledges but also understands the perspectives of those outside the professional structures, we find many parallels across the world. But there are also differences, such as the robust formalized responses to hobbyist enthusiasts (e.g., metal detectorists) in many countries in Europe and the application of an amnesty in Australia (Viduka, this volume) and Cyprus (Hardy Reference Hardy, Grove and Thomas2014). In such cases, collecting may not only be legally permitted, but the local and national heritage infrastructures have sometimes been adapted to formally incorporate the input of hobbyists into official heritage management and archaeological research. This may not feel to some like an ideal solution, but we urge readers to approach the articles in this volume with an open mind and a willingness to consider that there are a variety of ways to approach heritage challenges involving different sectors of the public.

A central focus of this issue is what might be considered the next steps in collaboration: moving from individual person-to person best collaborative practices and case studies to what can work in terms of policies, protocols, and legislation being implemented and evaluated in different countries. If successful, this can ensure that collector-generated data becomes part of the formal scientific and humanistic record. This kind of collaboration has been practiced successfully in some parts of the world, such as northern Europe, for several decades already. Consequently, the issue is considered either more or less sensitive in different countries, with a sliding scale of willingness to accept and work with nonprofessional hobbyists that is often situational to the local social, legal, and cultural settings.

Protocols are a core focus of the article by Elizabeth Marlowe. Taking the Society for American Archaeology's “Statement on Collaboration with Responsible and Responsive Stewards of the Past” (Society for American Archaeology 2018) as a starting point, Marlowe explores its implications for unprovenanced antiquities currently in the USA that originated elsewhere in the Classical world. As she notes, the many differences between collecting objects originally from the USA versus those imported from other countries suggest that a distinct framework may be needed for developing appropriate responses to the challenge of dealing with unprovenanced or poorly provenanced objects collected internationally. In the context of university museums as refuges for these problematic objects, she presents suggestions for best practices with which the objects can be researched and used for teaching in an appropriate manner.

The theme of citizen science and public participation recurs in this issue, as demonstrated in several of the articles discussing work in Europe and in the Australian case presented by Andrew Viduka. Charting how the management of underwater cultural heritage management has become increasingly professionalized in the decades since the 1940s, Viduka also overviews a 1993 amnesty intended to encourage private individuals to bring forward (eventually, tens of thousands of) objects collected from what are now protected shipwreck sites. The Australian government currently provides management for not only the artifacts in museums and other institutions but also those remaining in private possession.

Examples from Mexico and Uruguay show how not only finders of archaeological material but also those who actively collect such material can have meaningful relationships with students and professionals. Rafael Suárez, Maira Malán, and Elena Vallvé chart the changing attitudes of professionals toward private collectors. Once considered a problem with “useless” collections as far as research was concerned, in more recent times, private collectors have been recognized as one of the many groups of nonacademic stakeholders for Uruguayan cultural heritage. This is leading to changes in legislation as well as possibilities for updating the ways in which the next generations of archaeology students are educated.

Natalia Martínez-Tagüeña, Guadalupe Sánchez, John Carpenter, Luz Alicia Torres Cubillas, and Leopoldo Vélez discuss challenges and opportunities for engaging with collectors in Sonora, Mexico. They note a history of unequal relationships between professionals and the state, and others, including not only collectors but also local museums and descendant communities. They advocate a “solidarity archaeology” model, which is more inclusive and respectful of the many stakeholders of and perspectives on Mexican archaeological heritage. They focus on a pilot proposal to be implemented between the INAH Sonora and Indigenous communities, collectors, and local museums, as well as the experiences of the Comcaac Community Archaeology Project. As they note, collectors have experiential knowledge, and if included in projects, they can become allies and archaeological stewards.

In Europe, metal detecting is a popular hobby. Professional archaeologists therefore need to understand what it is all about, despite any personal feelings it may arouse. In fact, extensive research has previously been done about hobby metal detecting as a practice, detectorist motivations (e.g., Axelsen Reference Axelsen2021; Dobat Reference Dobat2013; Dobat et al. Reference Dobat, Deckers, Heeren, Lewis, Thomas and Wessman2020; Immonen and Kinnunen Reference Immonen and Kinnunen2020; Thomas Reference Thomas2012; Wessman et al. Reference Wessman, Koivisto and Thomas2016; Winkley Reference Winkley2018), and the scientific value of detecting finds (e.g., Martens Reference Martens, Martens and Ravn2016; Robbins Reference Robbins2013; Trier Christiansen Reference Trier Christiansen2019).

Building on that work, several of the articles in this special issue address this form of artifact seeking. Although the majority of finds are from plowed soils, they may nevertheless have scientific value (e.g., Fredriksen Reference Fredriksen2019; Wessman and Oksanen Reference Wessman, Oksanen, Halinen, Heyd and Mannermaa2022). Indeed, the many digitized databases of metal-detected finds that already exist in Europe and their widespread use in academic research projects testify to the value of metal-detected finds when reported and recorded to a usable standard. There are certainly long-term challenges for storing and sharing these data (with transnational infrastructure initiatives such as ARIADNEplus seeking solutions for aggregating them [https://ariadne-infrastructure.eu/]). Challenges likewise remain for the conservation and storage of the finds themselves (particularly the ones that remain in private ownership), as well as their movement, potentially over international borders. These challenges are also, however, opportunities for future research directions and for seeking co-creative solutions that involve all stakeholders.

In this vein, Irmelin Axelsen's article addresses metal detecting in Norway. Currently, metal detectorists are treated very differently depending on the personal attitudes of local heritage managers. Without a national system, collaboration might therefore become unequal, which is not fair. Consequently, Axelsen argues for more formalized collaboration between heritage managers and the metal-detecting community.

This also goes for group detecting events, both small and larger ones, which are often called “rallies.” In their article, Anna Wessman, Pieterjan Deckers, Michael Lewis, Suzie Thomas, and Katelijne Nolet adopt a pan-European approach to the challenge of group metal-detecting events in England, Flanders (Belgium), and Finland. There are obvious challenges with such detecting events when it comes to finds recording and to covering the costs of conservation of the objects. Therefore, there is an urgent need for strategies, guidelines, and recommendations not only for the heritage management but also for those organizing these events.

In addition to mitigating the risks of lost data and damage to archaeological sites, several projects in this special issue have investigated and even deployed solutions using principles of citizen science to encourage responsible collectors and to demonstrate the informational value of positive engagement with hobbyist artifact searchers. One way to investigate this is by doing research using written surveys.

Balázs Komoróczy, for example, discusses a questionnaire-based survey he conducted in the Czech Republic in 2017. Although Czech laws are still restrictive toward metal detecting, the survey suggests that the majority of professional archaeologists consider metal-detecting finds to be scientifically important and that they believe that cooperation with metal detectorists is necessary, beneficial, and acceptable. Professional opinions are crucial when it comes to developing new digital tools for metal-detecting finds, such as the “Portal of Amateur Collaborators” created in South Moravia in 2020.

Antonia Davidovic-Walther's article focuses on citizen science and the collaboration between archaeologists and metal detectorists in Germany. Taking a theoretical approach to first define this relationship between the knowledge production of professionals and volunteers, her article then describes the results of ethnographic fieldwork and a questionnaire survey. She uses these insights to provide examples of best practices as well as recommendations for future policies.