Ontology: Do we need 'electricity'?

[jannahastings]

Description of the issue

The ontology currently includes no class with the label "electricity". We do have "electrical energy" defined as:

Electrical energy is energy derived from electric potential energy or kinetic energy. [...] This energy is supplied by the combination of electric current and electric potential that is delivered by an electrical circuit.

[definition source Wikipedia]

Ideas of solution

Should 'electricity' be a synonym for 'electrical energy'? Or should it be a separate class in its own right?

Workflow checklist

• [x] I discussed the issue with someone else than me before working on a solution
• [x] I already read the latest version of the workflow for this repository
• [ ] I added this issue to the Project 'Issues'. If suitable, I add it to further Projects.
• [x] The goal of this ontology is clear to me

I am aware that

• [x] every entry in the ontology should have a definition
• [x] classes should arise from concepts rather than from words

[jannahastings]

@stap-m and @l-emele Any comments?

[l-emele]

In my understanding _electricity_ is a collective term. It comprises e.g. _electrical energy_, _electric current_ and _voltage_. Wikipedia has a similar view:

_Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. [...] Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others._

So I would not include _electricity_ as a synonym for _electrical energy_.

[l-emele]

I thought a bit about this and my conclusion is: We should include _electricity_ with a definition close to the one cited in my last comment. But we should not use it very much in the ontology but try always to use the more specific term like _electric energy_ or _electric current_. So that we show in our ontology that this term exists but in most cases it is not specific enough.

[l-emele]

@fabianneuhaus : In the telco today you mentioned that you would use _electricity_ as synonym to more than one class, Could you please elaborate your thoughts on _electricity_?

[l-emele]

So we basically have now two different proposals here:

1. The collective term. What would be the appropriate superclass? I would argue that it is a continuant, as electrical energy, electric currents, voltages, etc. may change over time but it stays _electricity_.
2. Fabian's suggestion to use _electricity_ as synonyms for classes like _electrical energy_, _electric current_, etc.

I would still prefer the first option as such a collective term is worth per se and can be used meaningful. An example is the electricity grid: It transports electrical energy, there are electric currents flowing and between the wires are voltages. So it can be stated that the electricity grid is associated to electricity.

[akleinau]

this feels slightly complicated as I don't think the concepts collected by this term are subclasses of it. "Electrical energy" for example fits better as energy, electric current is represented right now by the electric current unit etc. They are not parts of it either, if we don't implement it as a collection. Which would be a possibility as it's defined as a collective term.
@jannahastings do you have an idea?

[stap-m]

I get your point @akleinau. If we found an appropriate superclass for the set of phenomena called electricity, I'd also really like to include it.
Nevertheless, electricity is used synonymously for several terms in our domaine. Thus we should definitely (also) annotate electrical energy and others with this synonym label.

[jannahastings]

I think it would be great to add 'electricity' as a synonym to all the classes where it is used synonymously with another term in the domain. I think that would be the most accurate reflection of what is going on. It will highlight that this is an ambiguous term in itself, and show the recommended / preferred term for the different things, but at the same time people who search for electricity in the ontology will find what they are looking for.

[l-emele]

@jannahastings : So you are voting against an explicit class for the set of phenomena?

[jannahastings]

I am not necessarily voting against an explicit class for (perhaps) one of the phenomena, just against a single class that represents really diverse entities that cannot be classified beneath a common parent. Is there one usage that is the most common and makes sense to create a class for as well?

[stap-m]

At the moment, we just have electrial energy which would receive a label electricity.
Further, we have imported electric charge from UO. I guess this should not be changed by adding a label?

[l-emele]

It is weird that that class is called electric charge in UO and not electric charge unit as this class does not represent the charge itself but the unit of the charge. So I won't add the electricity label here.

[l-emele]

So we basically have now two different proposals here:

1. The collective term. What would be the appropriate superclass? I would argue that it is a continuant, as electrical energy, electric currents, voltages, etc. may change over time but it stays _electricity_.

2. Fabian's suggestion to use _electricity_ as synonyms for classes like _electrical energy_, _electric current_, etc.

Maybe we could do something like a poll among energy modellers which solution they would prefer? Maybe also the Steering Committee has an opinion?

[l-emele]

Conclusion from today's OEO Dev Meeting 12: Use electricity as an "alternative term" for classes like "electrical energy", "electric current", ... (only "electrical energy" is included in the ontology)

(And discuss general use of alternative term separately in issue #619).

I'll implement our solution for electricity.

[l-emele]

We have the following classes that contain the words _electric_, _electrical_ or _electricity_:

• electric charge
• electric current unit
• electric field strength unit
• electric heat pump
• electric motor
• electric potential difference unit
• electric vehicle unit
• electrical conductivity
• electrical energy
• electricity grid component
• electricity grid
• hydroelectricity
• battery electric vehicle
• fuel cell electric vehicle
• fuel-powered electric vehicle
• plug-in hybrid electric vehicle

As I understood our discussion, we do want to include electricity as alternative term for physical quantities like electrical energy, electric current etc, but not to objects like electric vehicles and electricity grid and not to physical units like electric field strength unit, right?

[jannahastings]

not to objects like electric vehicles and electricity grid and not to physical units like electric field strength unit, right?

That is also my understanding. In any case, if it is already part of the term name, there is no added benefit to adding a synonym as those users who search for 'electricity' will find it by partial matching.