Types of Digitization: Programmatic, On Demand, Forensic
Generally, digitization falls into three categories:
- On-Demand Digitization (aka Ad Hoc Digitization): Objects (or parts of objects) are digitized when a stakeholder (e.g. patron, researcher, curator), requests it
- Programmatic Digitization (aka Systematic Digitization): Collections are digitized in their entirety, in a planned manner.
- Forensic Digitization: an object is digitized before, during, and/or after some event such as a conservation repair/cleaning process, or an external loan.
The practical requirement to provide On Demand Digitization is obvious to anyone who has run a digitization program. Most stakeholders cannot wait for a particular object’s turn in a programmatic schedule, especially when the scale of the collection means the programmatic schedule is projected out many years (or even decades). A digitization program must provide for procedures and workflows to provide On Demand Digitization with turnaround time that will sufficiently meet the needs of their stakeholders.
The benefits of systematic digitization are obvious, but the scale of this benefit may not be. When it comes to digitizing a Cultural Heritage collection, the whole is often greater than the sum of its parts. By completing an entire collection, the stakeholders are provided a complete deliverable digital collection rather than piecemeal elements of one. Moreover, the pre-planning and efficiency in programmatic digitization can radically reduce the per-object cost of digitization provided high quality hardware and software are used [see Collating By Required Capture Window].
“Before we adopted the BC100 we were capturing around 10 plates per hour. Using the BC100 we now capture around 300 per hour. This allows us to digitize entire books (editors note: this is Programmatic Digitization), rather than just a few plates from each (editors note: this is On Demand Digitization), as we did with our previous slower system. Just as importantly, the BC100 captures a higher level of detail, which is important because our natural history plates have lots of small detail, important to the understanding of the object. With the images from the BC100 the viewer can zoom in to examine details, such as an insect, the coloring of a bird’s wings, botanical drawings, or a huge foldout map. Increasing both speed and quality has been a boon to our digitization program and to the users of our digital collections.”
– David Holbert, Imaging Specialist, Smithsonian Libraries
“To facilitate digitization of historical records it is imperative that all disciplines within a cultural heritage are represented in the development of digitization workflows. The Church History Library developed a ‘Digital Highway’ to facilitate effective digitization of historical records. A coordinator works with all disciplines to ensure records are reviewed according to access policies, metadata and finding aids are created and that the records properly handled. This has allowed the Church History Library to fulfill digitization requests in days rather than weeks or months.”
– Chad S. Barker, Manager, Preservation Planning & Operations, Church History Library
Scope Analysis: Material Type, Size, State
Before undertaking digitization, it is important to survey the variety of material present in the collection. Efforts to create universal conventions for breaking down a collection are in progress at The Getty Research Institute in the form of the Cultural Objects Name Authority. Such canonical hierarchies may be useful for planning a digitization program. They were not explicitly created for this purpose, however, and more utility may be gleaned by a purpose-made breakdown that is customized to a specific institution. The example below is well suited as a starting point for planning a digitization program, and can be made with any standard spreadsheet program using a rough estimate of quantities to help guide the process. Here, we have broken it down by type, size, and state, taking cues from which collection attributes call for special digitization considerations.
- Works on Paper: drawings, sketches, paintings, diaries, field notes, scrapbooks, ledgers, maps, blueprints, posters
- Works on Other Substrates: engravings, etchings, multimedia
- Reflective Photomechanical: silver prints, cyanotypes, tintypes, calotypes, moon print
- Transmissive Photomechanical: lantern slides, x rays, cyanotypes, glass plates
- Spaces: installations, architecture, scenics
- 3D Items: sculptures, fossils, material culture
- Organics: people, biological specimens
- Macro: anything smaller than A8, including 35mm film, microfilm, stamps, coins
- Normal: anything larger than A8 and smaller than A3
- Oversized: anything A3 or larger
- Binding: loose (unbound), T-Binding, bound, stapled
- Stability: stable, rapidly deteriorating
- Handling Risk: robust, fragile, very fragile, consumption
- Hazardous: mold, arsenic, lead, radioactive
Establishing the scope of the collection to be digitized is essential for both the prioritization of digitization and the proper selection of the hardware and workflows that will be used. For instance, a collection which contains 3D materials is ill suited to systematic digitization via a flatbed scanner. Ideally, the hardware and workflow software that can digitize the majority of the collection should be selected. It is imperative for institutions to examine their holdings and look for a solution that is versatile and accommodate the particular needs of their collections. For example, the same high-resolution digital back and raw workflow software can be used to digitize any of the above categorized material types. The ability to use the same hardware and software across a broad collection reduces the institutional training requirements involved, and consolidates hardware cost outlays.
It is especially important to make careful note of the type and quantity of “problem children.” These are the outliers of a collection which will require extraordinary time or effort to digitize. This could be because of size (e.g. in a bound material collection there may be a small number of especially over-sized manuscripts) or condition (e.g. fire-damaged or extremely fragile materials).
“We have handscrolls, we have prints, small paintings, large oil paintings, hanging scrolls, six-fold screens; we also have quite an extensive collection of 3D material: bronzes, sculptures, metals of all types. We have a mandate to photograph our entire collection and put it online… by the end of 2014.”
– John Tsantes, Freer|Sackler, The Smithsonian Institution
Leveraging Existing Collections Management Systems
One should never underestimate the amount of “housekeeping” required to maintain, curate, and provide long-term access to the tremendous quantity of files created during digitization projects. Perpetually maintaining digital objects require a range of ongoing expenses such as on-site storage, off-site redundant backups, electricity, maintenance, and migration costs. The use of Preservation Digital Objects more easily justify this ongoing cost than those of digital objects that do not meet, or have not been verified to meet, preservation standards.
Organizational systems such as an electronic collections catalogue, collections management system, and/or digital asset management system will help optimize workflow by providing structure to the materials to be imaged and can also help track which collections have been digitized. The ability to assemble collections by likeness and size tremendously increase the efficiency of digitization program and greatly enhance the conversion of collections into Preservation Digital Objects. If the collections catalogue has a digital asset management component, one can characterize the quality of the digital objects using FADGI type guidelines, and segregate images that are true Preservation Digital Objects from lower-quality images. This can help guide which digital assets are worth the costs of maintaining.
Long Term Preservation of and Access to the Digital Collection
The result of a digitization program is the creation of Preservation Digital Objects. These PDOs become part of the collection of the institution and must be preserved and properly cared for. When planning a digitization program this obligation and its ramifications must be considered.
The most obvious implication of an expanded collection of PDOs is the need for more digital storage. Every PDO requires digital storage space, so more PDOs means larger pools of storage are required. Less obvious is that a larger digital collection usually implies more digital traffic in the form of visitors to an institution’s website or collections portal. Handling this increased bandwidth of online visitors may require upgraded servers or a more expensive website hosting plan. Also, those visitors may require more sophisticated tools (e.g. better filtering, searching, browsing) as the online collection grows; manually browsing through a few hundred thumbnails is tedious but practical, while manually browsing through a few million thumbnails is not practical. Adding such tools to a web platform, or switching to a more sophisticated platform which includes them can be a lengthy and expensive process.