Digital obsolescence occurs when a digital object or its associated software, hardware, or format becomes outdated or unsupported, making it difficult or impossible to access, use, or interpret. This can be caused by technological changes due to rapid innovation and evolution of technologies, market changes such as commercial decisions or legal issues, and social changes like user preferences. Digital obsolescence can have serious consequences for your library collections, such as loss of access if you don't have the appropriate software, hardware, or format; loss of functionality if your digital objects are incompatible with your current systems; and loss of context if you lack the necessary metadata, documentation, or standards.
Digital degradation is when a digital object or its storage medium deteriorates or suffers damage over time, which can affect its quality, completeness, or accuracy. Physical factors, such as environmental conditions like heat, humidity, dust, or light, can impact the performance or lifespan of storage media like CDs, DVDs, hard drives, or flash drives. Human errors, accidents, or malicious actions such as deleting, overwriting, or corrupting files can also compromise the integrity or security of digital objects. Additionally, software bugs, viruses, or format errors can cause errors or inconsistencies in digital objects and their metadata. Digital degradation can have serious consequences for library collections like loss of quality due to visual or auditory defects; loss of completeness due to missing or unreadable parts; and loss of accuracy due to incorrect or inconsistent information in digital objects and their metadata.
Migration is a preservation method that involves transferring or converting digital objects or their formats to newer or more compatible ones, to ensure their continued access and functionality. Migration can be done manually or automatically, periodically or on demand, depending on your library's policies and procedures. This method can help you prevent or overcome digital obsolescence by updating, enhancing, or consolidating your digital objects. However, it also has some challenges and limitations, such as cost, quality, and compatibility. Migration can be expensive and time-consuming when dealing with large or complex collections, and it can introduce errors or alterations in your digital objects that affect their originality or fidelity. Additionally, migration may create new dependencies or incompatibilities with existing systems, tools, or metadata.
Emulation is a preservation method that involves recreating or mimicking the original software, hardware, or environment of your digital objects, to enable their access and functionality. This can be done with software applications or hardware devices that simulate the behavior or appearance of older or obsolete ones. Emulation can help you prevent digital obsolescence by preserving objects in their original state, reproducing them as intended, and supporting those with unique features. However, emulation also has some challenges and limitations like cost, quality, and compatibility issues. It can be expensive and time-consuming to develop custom solutions for emulation, which can also introduce errors or variations in objects. Additionally, emulation can create new dependencies or incompatibilities with your current systems, tools, or metadata.
Replication is a preservation method that involves creating and storing multiple copies of digital objects or their formats in different locations, devices, or media, to ensure their availability and integrity. This can be done manually or automatically, frequently or occasionally, depending on the library's policies and procedures. Replication can help reduce the risk of losing digital objects due to physical, human, or logical factors, as well as increase the chances of recovering them if damaged or corrupted. Furthermore, it distributes the load and responsibility of preserving digital objects among different partners or stakeholders. However, replication has some challenges and limitations such as cost, quality, and compatibility. Replication can be expensive and resource-intensive if additional storage space is needed. It can also introduce errors or discrepancies in digital objects, affecting their completeness or accuracy. In addition, it can create new dependencies or incompatibilities with existing systems, tools, or metadata.
Checksums are a preservation tool used to generate and verify numerical values that represent the content or structure of digital objects or their formats, to detect and prevent errors or changes. Different algorithms, such as MD5, SHA-1, or CRC can be used to generate checksums. This process can help manage digital obsolescence and degradation by identifying objects by their unique values, comparing them for consistency, validity, or authenticity, and reporting them to document their status, history, or provenance. However, checksums can be costly and time-consuming for large or complex collections, inaccurate or unreliable when generated or verified with different algorithms, and incompatible or incomprehensible if not supported or documented by systems, tools, or metadata.