In regard to curation, there are significant differences in the content of American archaeological collections that relate to the eras in which they were recovered, which is explained in greater detail here. For the purposes of discussion, some operational terminology is needed in order to differentiate collections by their composition and their respective challenges:
"Antiquarian" Collections - These are generally the earliest collections and were obtained by amateurs and/or investigations sponsored by state or local historical societies and sometimes universities. These collections are primarily artifacts from mortuary contexts (e.g. mounds) or surface contexts. Most artifacts are formal tools or ornaments, while more common domestic debris is usually absent. Ecofacts are uncommon. Provenience information is often present (although often imprecise) and ranges from county-level provenience (e.g. "Montgomery County, Ohio") to site-level (e.g. "Lichliter" or "33 My 23") or possibly feature-level provenience (e.g. "Mound 10, Burial 4"). Contextual data is minimal or absent. Maps and notes are minimal or absent. No more collections of this type are being generated by the professional community because such non-systematic activity in the modern era would generally be treated as looting. Data are in analog format, often hand-written. Some or all data may have survived only because it was hand-written on the artifacts themselves.
"Amateur" Collections - These collections are common in museums and historical societies. Some come from the proverbial (or literal) farmer's coffee can - surface finds collected opportunistically by a landowner (e.g. grandpa's collection of arrowheads from plowing his fields). Most have no associated data for individual objects, but may retain some provenience in that all objects originated from a discrete parcel of property. Other amateur collections are those collected by hobbyists (e.g. "arrowhead hunters") or avocational practitioners. These are composed primarily of surface finds from non-systematic amateur surface activities. Contextual data is usually absent, but county-level or site-level provenience is common. Maps and notes are minimal or absent. Few new collections of this type are being generated as a result of changes in farming practices, the decline of "artifact hunting" as a hobby, and the commercialization of artifacts that discourages owners from donating them to museums or historical societies. Data are usually in analog format, often hand-written. When provenience exists for individual artifacts, this information was often hand-written on the artifacts themselves. More prolific collectors sometimes created inventories or ledgers of their collections. Undocumented amateur collections can be dubious for research because it is common for amateur collectors to trade, buy, or sell specimens and intermingle the resulting specimens without documenting their disparate origins.
"Survey" Collections - These collections are more common in collections curated by state or federal agencies, including state-level historical societies and universities. These are most frequently generated by CRM companies, university field schools, and government agencies. They result from systematic surveys over large areas for the purposes of documenting new archaeological sites, often through visual surveys (e.g. collecting artifacts from plowed agricultural fields) or shovel-testing (systematic shallow digging at regular intervals across a field). Some lesser amount of these collections represent small exploratory test excavations conducted after survey to evaluate the potential significance of individual sites. Collections usually consist of artifacts, but few ecofacts or subsurface finds. Most are from projects no older than recent decades and these collections are the most common type being collected in the present day due to legal mandates (e.g. Section 106 of the National Historic Preservation Act.) Many of these collections are well-documented, mapped, and usually have site-level provenience at a minimum. Data format may be analog or digital, depending on the era in which the collection was generated. In recent years, most survey provenience data is now collected with GPS, which yields highly precise digital spatial coordinates. Geophysical survey is increasingly being used as an efficient, non-intrusive method of data collection alongside traditional survey methods. Geophysical data is exclusively digital in format.
"Legacy" Collections - These were collected in the 1930s or later, especially from the 1960s onward and continuing to the present. These are analog collections that were obtained through controlled excavations and have modest to large amounts of contextual data. Provenience is usually feature-level at a minimum, but may include provenience from individual levels of features. Maps and notes are often extensive. Collection size can vary considerably, but all types of artifacts, ecofacts, and subsurface features are likely to have been recovered or documented. These are often from lengthy excavations, the nature of which varies considerably across different types of sites and regions. They originate from projects sponsored by universities; state or local historical societies; CRM companies, federal or state agencies; and museums. Although they may have digital inventories or finding aids, these are primarily analog collections where most or all of the non-object data (maps, field notes, photographs, etc.) exist in analog form. Equivalent collections continue to be generated in the present by universities, museums, and CRM companies where some data are collected in analog format (e.g. unit or feature maps; field notes) and some in digital format (e.g. total station; GPS; photographs). In modern projects, analog data are usually reformatted into digital format in post-field processing.
"Born-Digital" Collections - These are new collections with associated digital data that were obtained through controlled excavations and have modest to large amounts of contextual data. Provenience is usually feature-level at a minimum and spatial positions may even be measured with centimeter or sub-centimeter precision. Maps and notes are extensive and standardized. All types of artifacts, ecofacts, and subsurface features are likely to have been recovered or documented. These are often from trench or block excavations, the nature of which vary considerably across different types of sites and regions. There are probably very few existing collections where all information is born-digital, but we anticipate that such collections will become common in the near future. Although it may be decades until digital data collection completely replaces analog (if ever), some CRM companies, government agencies, and universities have already begun the transition some time ago. Most archaeologists have been using digital cameras and collecting spatial data with total stations or GPS for many years, but the movement to using tablet-based entry for other kinds of field data will likely grow considerably in the foreseeable future. Adoption will be uneven: the high expense of equipment and software will likely result in a slower adoption by universities, museums, and smaller CRM companies. Born-digital data collections are currently structured around multiple independent digital technologies (e.g. GIS technology; digital cameras; geophysical data collectors), but some of these functions will likely be consolidated into fewer devices over time or linked together through enterprise level cloud applications.