We've all heard the warning about "comparing apples to oranges." But knowing that something is an "apple" or an "orange" is not always as simple as it seems. In the NASA Mars Orbiter accident, for example, engineers failed to recognize that the Orbiter's velocity system was measured in metric units ("apples") while its trajectory system was measured in English units ("oranges"). The results were truly catastrophic (see exhibit 1.1). While loss of life is not an issue with education data, serious problems may occur when data are used improperly, possibly affecting teachers' careers, school budgets, and most importantly, children's education.
Metadata1 are defined as "data about data." A more technically precise definition is "structured information that describes, explains, locates, or otherwise makes it easier to retrieve, use, or manage information."2 In other words, metadata provide the context in which to interpret data and information. For example, in the case of the NASA Orbiter, metadata would have helped analysts determine the measures were metric and translate them into English units to avoid confusion and error. While the loss of the Orbiter is an extreme example of the value of metadata, countless data systems, including education data systems, could drastically improve data quality and data use by instituting robust metadata systems.
In the complex world of education data, answers to even apparently straightforward questions often depend on highly complicated and technical data. Take, for example, the "simple" question, How many eighth grade English teachers are in your schools? Exhibit 1.2 illustrates how the "correct" answer depends on the definition of each separate word or phrase in the question. On one end of the spectrum, there may not be any full-time certified English teachers teaching an English class to only eighth-grade students in the single middle school in the district this semester. At the same time, 50 or more full- or part-time teachers may be leading reading, writing, or language classes with at least one eighth-grade student at some point during the academic year. Clearly, the "right" answer depends on the context of the question and the data being used to answer it—and metadata provide that context.
Numerous cases in the field of education further illustrate the need for metadata. For example, consider a school superintendent's surprise when she stays up late preparing a presentation that uses real-time online data, then finds the results are different in front of her audience the next morning because the database was updated overnight. Access to metadata about the database's update cycle would surely have helped that superintendent. Or consider a state education agency that spent $1,000,000 on a new software application, but then cannot upgrade it without spending an additional $500,000 because the system was not properly documented during its original development. Metadata recording technical and management choices throughout the application's development would likely have solved this source code problem and allowed for less costly ugprades.
While using up-to-date data in a presentation and properly documenting technical specifications have always been important, the concept of metadata, or data about data, has never before been so relevant to educators. In this era of data-driven decisionmaking, education organizations and their constituencies place tremendous value on using data to inform instructional and management practices. In contrast, 20 years ago educators rarely used data for decisionmaking as a standard business practice; instead, school leaders often relied on impressions, opinions, and even instincts. Today's enhanced use of data is further complicated by the sheer volume of information collected. With more data to organize, access, and understand than ever before, a metadata system is an essential tool for accomplishing these vital information management tasks.