An item bank is a specialized database, which stores and organizes a collection of items and associated data (Vale, 2006). Although simple in definition, an item bank’s structure is generally complex. It must be flexible enough to store a great deal of information used to create the assessments students see while also supporting the ever-evolving life cycles of an assessment program. An item bank is the most interconnected part of an assessment program and arguably the most important. Thus an item bank and the applications used to access it, i.e., an item banking system, must have clearly defined structure for items, tests, and their characteristics, well-defined roles with appropriate permissions for users, and supports for version control. These features support the core functions of an item bank, which are the: (i) entry and maintenance, (ii) storage, and (iii) retrieval of item and test data.

Clearly defined and flexible database structures for items, tests, and associated data are the key in supporting these functionalities. Each and every relevant aspect of each item must be stored, including the content, supported student interactions, and scoring rules. Doing so is a nontrivial task as an item bank must be general enough to store a variety of item types and flexible enough to handle the introduction of new item types in the future. With the increasing complexity of educational assessments, the item bank must also be able to accommodate complicated interrelationships between items, including item sets (e.g., testlets; Wainer, Bradlow, & Wang, 2007) often used in response to reading passages or in simulations. In addition to storing items and associated data, including item metadata and assets like multimedia, item banking systems must also store a variety of data related to tests, including test metadata, supports for form assembly, and, if needed, a variety of information related to adaptive testing.

All of this data is generally housed within individual elements or objects within a database that makes up the item bank. These data structures are critical, as an item banking system interacts and supports every aspect of a program of educational assessment. Given the central role of an item banking system within an assessment program, it must be able to scale and adapt as the program evolves – without careful design item banking systems can, and all too often have, become bottlenecks within assessment programs.