In early 2022, nearly two years after Covid was declared a pandemic by the World Health Organization, experts are pondering a big question. When did the pandemic "end"? So what is the answer? What criteria should be used to determine the 'end' of the pandemic phase of Covid? These are deceptively simple questions with no easy answers. I'm a computer scientist, doing research on ontology development. In computer science, ontology is a means of formally structuring subject knowledge, using entities, relationships, and constraints, so that computers can process it in a variety of applications and humans can become more precise. Can help Ontologies can discover previously overlooked knowledge. In one case, the ontology identified her two additional functional domains for phosphatases (a group of enzymes) and some new domain structures for the enzymes. Ontologies are also the basis for the Google Knowledge Graph behind these knowledge panels to the right of search results. It would be useful to apply the ontology to the question originally asked. This approach helps explain why it is difficult to set a threshold for declaring a pandemic "over." Informally speaking, an epidemic is an event that occurs in organisms over a limited period of time in which multiple instances of an infectious disease affect a community of organisms residing in a particular region.  COVID easily ticked all eight boxes, at least in early 2020. A properly automated thinker would have classified this situation as a pandemic. But now,in early 2022? Whether there is a worse variant of worry is a million dollar question. Further ontological analysis is required. Pandemics at least expand the area where infection occurs. This process involves gathering definitions and characteristics from subject matter experts such as epidemiologists and infectious disease scientists, examining relevant studies and other ontologies, and examining the nature of entity 'X'. . The "X" here is the pandemic itself - look at the properties of this entity, not just the short definition. Such a precise characterization of the "X" also appears when the entity is "not X will be For example, if X = house, then the house property means that everything must have a roof. If an object doesn't have a roof, it's definitely not a house. These capabilities enable the creation of accurate and formal specifications, supported by additional methods and tools. From this it follows logically that the 'X' what and when the pandemic is over or not over. If not, at least I can explain why things aren't that simple. This kind of accuracy complements the efforts of medical professionals and helps people be more accurate and communicate more accurately. It forces us to make implicit assumptions explicit, clarifying where disagreements may exist. Ontologically, therefore, a pandemic is an event (a “success”) that unfolds over time. There are many characteristics of pandemic classification, not all of which are well-defined and not all of which imprecise boundaries have been established. Conversely, classifying an event as 'non-pandemic' would be equally inaccurate. This isn't a complete answer to what the pandemic is ontologically, but it does shed some light on the difficulty of calling it 'over' - and that there are disagreements about it. It shows well.

John Mathews