What is a Dictionary?
Collecting words and their defintions into dictionaries is the work of lexicography. Funk and Wagnall’s Standard Dictionary of language specifies the meaning of the word ‘dictionary’ as ‘1. A reference work containing alphabetically arranged words together with their definitions, pronunciations, etymologies, etc. 2. A lexicon whose words are given in one language together with their equivalents in another. 3. A reference work containing information relating to a special branch of knowledge and arranged alphabetically.’
A research science dictionary is 1. A reference work containing a collection of terms that are used in a scientific community along with information that is required to understand each term. 2. A reference work that prescribes a standard for the community language. 3. A reference work written to help translate terms between texts and languages (i.e.. from a journal to a computer processing program). While a standard language dictionary helps a reader understand an unfamiliar word by relating it to information categorizing that term specifically (internal), a scientific dictionary helps researchers understand and utilize data collected elsewhere by defining terms both internally and externally in the context of the community. The definition of a term may be dependent on any combination of the following features:
Internal
Human Usage: Abbreviations, formal names and publication preferences must all be taken into account in the definition of a term so that it can be widely recognized.
Standards: Standards to which a term relates should be described fully in a dictionary. For example, measurement terms will often refer to International System of Units (SI) standard, so a unit dictionary will include definitions that relate a measurement back to the parent SI unit of the same unit type.
History: A dictionary can also bridge technology leaps and changes in community practice. For instance, previously used data processing programs might have needed one set of information while current programs use another, or changes in data collection from human-gathered to instrument-collected can cause language barriers to data comparisons. A dictionary, in providing language used for all cases, can provide back-compatibility to datasets that might not otherwise be useable.
External
Community Culture: (see Databits article: “Designing a Dictionary Process: Site and Community Dictionaries”) “Although names and their definitions are seemingly mundane and even trivial concepts, this does not mean that the articulation, exchange, and blending of unit and attribute names are simple matters. Names go to the heart of local work practices and of data interoperability.” Local nicknames propagate through work practices and become standard within that community; recognizing and including both local and intra-community culture as part of a dictionary creates a human-accessible document for translation between groups of people.
Computer Usage: In this age of rapidly increasing technological power, computers are taking over parts of data analysis previously preformed by humans. To do this, the computer and specifically any programs need to know many things about the data, for example if they are binary or ASCII, string or integer, etc. A dictionary, as Funk and Wagnalls noted, is a tool to translate from one language into another, in this case from human-accessible data into programming terms for automated computations.
Technology Infrastructure: Database software, analysis software and programs themselves all need different types of descriptors in order to run efficiently, and to allow the greatest access, search and display features. A dictionary can provide many types of technological information to facilitate cross-platform and cross-system access, for example the format for the dates and times present, etc.
Dictionary Purpose
A dictionary is created for a number of reasons listed above, including describing terms and prescribing a standard, however the purpose of a dictionary is also directly tied to the needs of the end-user and the audience for whom it is created. In fulfillment of these needs, a dictionary’s purpose also includes providing access to shared data, aiding in database searches, providing information needed for interoperability, guiding entry-level projects and informing controlled vocabulary work.
Uses for Different Sized Groups
A small team of people such as a laboratory group may use a dictionary in order to move away from ‘tribal knowledge’ and articulate their local standards for field acquisition and data processing. On this level, a dictionary can also bring together the language of people with different job descriptions; a field technician and lead scientist can use a dictionary to log and document all appropriate methods and acquisition metadata, a programmer can use a dictionary in order to optimize processing code, and an information manager can use a dictionary in order to efficiently archive files into a database or reference the proper standard, etc.
When multiple small groups are collaborating on a project, the dictionary becomes a tool of interoperability that allows the merging of datasets collected and processed by the individual groups on the human and computer levels. Intra-group differences in methodology and abbreviations for like measurements are clearly articulated and possibly resolved in a single dictionary or a combination of dictionary types (see following Dictionary Types section for a brief list).
A community-wide dictionary allows for automated data comparisons spanning many differences such as in acquisition methodologies. Carbon production for example can refer to land or water-based measurements collected with vastly different methodologies, processed using different calculations, etc. Dictionaries enable the collation of carbon production data from many sources, enabling comparisons and faciliting any potential unit conversions.
Dictionary Types
There are many types of dictionaries, a few examples are listed here:
A code dictionary is a mechanism by which coded entries in a dataset can be explained by outside documentation. Codes are a straightforward and efficient way for a group to communicate locally, and storing the code information in a dictionary format provides a centralized clearinghouse for this important knowledge so users not familiar with the colloquialisms can reference material without speaking to an individual within the group. A common use of codes is in naming field stations; a code dictionary might contain a list of field station names translated into latitude and longitude, or pointers to a paper describing the field grid layout and station positions. An acronym dictionary would also fall under this type.
A unit dictionary links local measurements to a standard or an accepted scientific convention (i.e. the SI standard of units) and bridges local abbreviations and unit names to language preferred by journals and technical publications. From a unit dictionary, a user can generate a list of all entries of (SI) unit type ‘length’, convert between them and provide proper abbreviations as used in a domain journal. Unit dimensions and types are also an important part of the unit dictionary as this information facilitates automated conversions and informs the creation of new units that may not directly relate to the standard, such as units of abundance.
An attribute dictionary details information about attributes stored in a database, including links to unit and code dictionaries. For example, a temperature measurement might be defined by an attribute dictionary with information including what type of temperature is recorded (sea surface temperature), what units the measurement is in (pointer to the unit dictionary entry for ‘Celsius’), a description of the value (a real number, stored as a float with a precision of 0.01). use micromolar example here?
A method dictionary is one way of standardizing methodologies and aiding in metadata entry to a database. Rather than writing a complete method section for each dataset, references to predetermined and accepted practices will pull the proper information out of a method dictionary for insertion into a database or file. find USGS example
Dictionary Vision
A dictionary results from a collaborative process where people with different research goals from different scientific projects, and even from different branches of science, come together with the goal of comparing and/or sharing field measurements and models as well as providing a framework for interoperability to answer larger scientific questions. A dictionary bridges differences in datasets to enable direct comparisons and it fosters understanding between scientists who may use different terminology, computer processing techniques or operating systems. Further, it provides a mechanism to use collected data for a purpose beyond it’s original scope.
Deciding what information is needed to define a particular term involves the interpretation and discretion of the dictionary creator(s), but in this openness and lack of restriction is a flexibility that makes the notion of a dictionary so useful and important. Science is not a rigid field, it is fluid and ever-changing as hypotheses are proved and disproved, and as new perspectives, concepts and technology expand our ability to measure, analyze and perceive the world. A dictionary is dynamic in order to accommodate changes in understanding while at the same time serving as a static standard to inform data use.
