This pairing provides a rough-and-ready conceptual frame for some of the discussions of the Federal Agencies Digitization Working Groups. The distinction between informational and artifactual is most easily discerned in the case of textual materials (roughly speaking, the text as compared to images of pages) and more difficult in the case of pictorial materials (the picture as compared to the structure of the physical element, e.g., detailed documentation of a photonegative, the underlying paper, and other physical formats).
Informational value. All works found in libraries, archives, galleries, and museums may be consulted or studied for the sake of the information they contain, or interpreted by researchers in order to develop additional information. In some cases, curators or end users will agree that this informational value is "all there is." Some books, for example, are valued for the "words in the text," with little regard for layout or design. Thus the reproduction of an "informational-value-only" book may not require the representation of the entire physical work, e.g., blank pages and the cover may be omitted. Some manuscript items, e.g., documents in the records of a government agency, are perceived as having little artifactual or intrinsic value, even though researchers require an image of the document (i.e., a facsimile) in order to see signatures, stamps, or other markings. Facsimiles comparable in quality to a good photocopy will often suffice for informational-value-only manuscript items. Meanwhile, in the case of pictorial materials, it is often the case that a high resolution image will capture a picture's full information content but will not yet contain sufficient detail to document the physical structure of the underlying material (see Establishing Spatial Resolution Requirements for Digitizing
Artifactual value. Some works found in libraries, archives, galleries, and museums have artifactual or intrinsic value in addition to informational value. End users may seek images that are suggestive of the aesthetic experience produced by the original work, insofar as that experience can be provided by a reproduction. In the case of textual materials like books, end users may also seek images and/or image sets that convey a sense of the original item as a whole, e.g., a reproduction that includes images of the blank pages, binding, spine, and cover art. Items with artifactual value require higher resolution (and generally color) images than do information-only items. The desire to reproduce the entirety (or as near entirety as possible) of an original physical work with artifactual value will lead to the production of a virtual replica. In the realm of object conservation and analysis, scanning projects may seek to document the physical structure of an item, e.g., to document the pigments and underlying parchment in a medieval illuminated manuscript. Projects may also seek to reproduce the structure of newer materials; see for example the discussion of the "artifactual" imaging of photographic negatives and transparencies in Establishing Spatial Resolution Requirements for Digitizing
Transmissive Content. The documentation of physical structure often entails microscopic imaging and may also employ multispectral or hyperspectral imaging to record electromagnetic radiation beyond the visible spectrum, e.g., ultraviolet and infrared light.