Allotrope Data Model (ADM) Availability
Release Naming Conventions (Maturity)
The AFO and ADM releases are named according to a simplified model of the W3C classification system. These levels are designed to convey the level of maturity of a particular model or term. Note that different terms and different data models within the Allotrope ecosystem will have different maturity levels, and that maturity levels will change over their lifetimes.
Working Draft (WD)
All models and terms start their lives as an implicit or explicit Working Draft. This level indicates that the content is under active development and may change significantly before being promoted to another level. Allotrope does not recommend the incorporation of working draft models into external software.
The WD is intended to be a community preview of current work in progress to increase the visibility of domains being developed in a centralized location within the main ADM repository. While Working Drafts are subject to major revision at any time, they often contain subparts which may be useful when modeling other domains; this allows working groups to communicate ideas and norm on shared patterns early, streamlining governance.
Terms submitted as a Working Draft are eligible for assignment of official Allotrope IRIs and require only a draft definition and a preferred label. As long as definition semantically is the same, the minted IRI will not change and can make it to full maturity.
Lastly, in the event that current work needs to be paused or put aside for some time, working groups should consider developing their models into Working Drafts so that the work can be built upon in the future.
Candidate Recommendation (CR)
A Candidate Recommendation term or model has been through semantic governance and has the approval of both the original development group and the Principal Semantic Engineer (PSE). Models in the CR state will not change in content for that particular release, but may change for technical reasons to address bugs akin to a software hotfix.
Models in Candidate Recommendation are considered by Allotrope to be stable enough for incorporate into external software and processes.
A Recommendation represents the highest level of maturity for a term or model. Artifacts that are Recommended are frozen and will not change for that revision. New developments or other changes will result in a new version of the model.
All models, whether simple or complex, take the form of a semantic graph, which uses semantic triples to encode information. These semantic graphs have varying complexity that is driven by the complexity of the scientific domain that is being modeled. For many domains, a simpler set of triples which represent key/value pairs may be sufficient to faithfully represent the data. In other cases, the need to represent data about multiple objects necessitates connections between these key/value pairs which creates a connected graph. When starting, the suggested approach is to choose the simplest model which can represent the information. As all graphs live on a continuum, it’s possible to enrich a simple model over time to capture more complex relationships. Thus, it’s not really appropriate to say a Tabular or Connected Model approach is an either-or proposition; they are both semantic graph models of varying complexity.
Tabular Model: For domains where there is a single business object which is being measured and all of the measurements are directly related to this object, a tabular approach can be used. The tabular simplifies modeling by capturing just the individual measurements and associated measurement units and attaches them to a single entity being measured using a leaf node data pattern and simple aggregation patterns.
Another way to think of tabular models is as a set of key/value pairs, where the keys can be clearly distinguished without ambiguity and no references are required between keys (they can stand alone and accurately describe the data without relating to anything else.) Note that the context of the key/value pairs is represented only by the ADF file they are defined within; there may be no central node which connects the different keys. Tabular models are quick to assemble but lack the flexibility of full graph models. Nevertheless, tabular models, if constructed correctly, can be enhanced into full graph models as desired; many domains can be completely modeled using a tabular approach and no further expansion into a full graph is necessary.
Graph Model: For domains where there are multiple business objects being modeled or there are complex relationships such that it is insufficient to capture just the simple outputs of a single entity, a connected graph model richly models the different relationships in a complete, connected graph. An example of a connected graph model is the Allotrope LC-UV ADM.