This is the ontology of the MAC group. MAC Ontology A computational method, tool, or algorithm that produces predictions or scores from biological sequence or structure data. Referenced by observation FDOs of Types 3–6 via `mac:hasPredictionMethod`. Instances carry one or more `cito:citesAsAuthority` URIs identifying the published descriptions of the method. Computational Method An abstract parent class for computational predictions about a Spike RBD variant, produced by a named computational method. Concrete subclasses cover specific predicted quantities (`mac:ComputationalPredictionRMSD`, `…SASA`, `…PLDDT`, `…AgMata`). Anticipates additional computational prediction types as siblings without restructuring the hierarchy. This class is abstract: all instances belong to one of its concrete subclasses. Computational Prediction A computed prediction of the aggregation propensity of a Spike RBD variant, produced by the Bio2Byte AgMata method. The score is sequence-derived and is therefore predicted once per variant rather than once per structural-prediction method. Computational Prediction AgMata A computed prediction of the Root Mean Square Deviation between a predicted structure of a Spike RBD variant and a reference structure, produced by a named computational structure-prediction method. Computational Prediction RMSD A computed prediction of the Solvent Accessible Surface Area of a Spike RBD variant's predicted structure, produced by a named computational structure-prediction method. Computational Prediction SASA A computed prediction confidence score (predicted Local Distance Difference Test) for the structural prediction of a Spike RBD variant, produced by a named computational structure-prediction method. Computational Prediction pLDDT An experimental observation of binding affinity and expression level measurements for a Spike RBD variant, determined by deep mutational scanning (Bloom Lab protocol). One FDO records all six DMS metrics (`bind`, `delta_bind`, `expr`, `delta_expr`, `confidence_bind`, `confidence_expr`) for a single variant. Experimental DMS Observation An experimental assay or measurement protocol that produces empirical observations about biological entities. Referenced by Type 7 observation FDOs via `mac:hasExperimentalMethod`. Instances carry one or more `cito:citesAsAuthority` URIs identifying the published descriptions of the assay. Experimental Method An abstract parent class for empirical observations produced by laboratory assays on a Spike RBD variant. Currently has one concrete child (`mac:ExperimentalDMSObservation`, deep mutational scanning); the forthcoming Bosch extension adds `mac:ExperimentalCellSortingObservation` as a sibling. This class is abstract: all instances belong to one of its concrete subclasses. Experimental Observation An abstract parent class for methods, tools, assays, or surveillance platforms that produce observations within the MAC FAIR Digital Twin substrate. Concrete subclasses distinguish computational methods (`mac:ComputationalMethod`), experimental methods (`mac:ExperimentalMethod`), and observational/surveillance methods (`mac:ObservationalMethod`). Instances of any concrete subclass carry one or more `cito:citesAsAuthority` URIs identifying the published descriptions of the method. This class is abstract: all instances belong to one of its concrete subclasses. Method An abstract parent class for all observation-layer FDOs in a MAC FAIR Digital Twin. Concrete subclasses include `mac:RealWorldOccurrence` (Type 2), `mac:ComputationalPrediction` and its sub-hierarchy (Types 3–6), `mac:ExperimentalObservation` and its sub-hierarchy (Type 7), and `mac:WHOVariantClassification` (Type 8). Every member links to the FDT's anchor (a `mac:SpikeRBDVariant`) via `mac:isObservationOf`. This class is abstract: it carries no direct instances; all instances belong to one of its concrete subclasses. Observation An epidemiological surveillance system or data-collection platform through which real-world occurrences of biological entities are documented. Referenced by Type 2 observation FDOs via `mac:hasSurveillanceMethod`. Instances carry one or more `cito:citesAsAuthority` URIs identifying the published descriptions of the surveillance platform. Observational Method A documented detection of a SARS-CoV-2 Spike variant in the real world, as reported in a surveillance database (typically GISAID). The occurrence is anchored to a specific collection date and to a GeoNames-identified location. Real-World Occurrence A variant of the SARS-CoV-2 Spike receptor-binding domain (RBD, 195 residues) produced by one or more amino-acid substitutions from the wild-type Wuhan isolate (UniProt P0DTC2). This class is the type of the anchor FDO (A_r) of a FAIR Digital Twin; all observation FDOs link to it via `mac:isObservationOf` and collectively constitute the FDT. Spike RBD Variant Uncertainty Model Documentation of the model used to compute or estimate uncertainty. A SARS-CoV-2 variant for which the WHO has identified evidence of growth advantage or immune escape and that is being monitored precautionarily pending further characterisation. Variant Under Monitoring A SARS-CoV-2 variant designated by the WHO as carrying evidence of increased transmissibility, increased disease severity, or significant reduction in vaccine or therapeutic effectiveness. Variant of Concern A SARS-CoV-2 variant designated by the WHO as carrying genetic markers associated with phenotypic changes and demonstrated epidemiological impact warranting enhanced monitoring. Variant of Interest An abstract parent class for the World Health Organization's controlled-vocabulary risk designations applied to SARS-CoV-2 variants: Variant of Concern (`mac:VOC`), Variant of Interest (`mac:VOI`), and Variant Under Monitoring (`mac:VUM`). Used as the range of `mac:hasWHOClassification`. This class is abstract: all instances belong to one of its concrete subclasses. WHO Designation A classification of a SARS-CoV-2 lineage according to the WHO risk framework (VOC / VOI / VUM), with a specified assignment date and reference URL. Time-stamped because designation status changes over time. WHO Variant Classification has I uncertainty estimate Links a dataset to its I uncertainty estimate. has RT uncertainty estimate Links a dataset to its RT uncertainty estimate. has m/z uncertainty estimate Links a dataset to its m/z uncertainty estimate.