Naming convention: Population v. ``Has population''...renaming??
- The naming convention discussion is a good one and is vitally important.
- has type is easily confused with has population for us newbies (it was for me) and when you're confused by the assignment statement you're not off to a good start.
- I was confused by the frequent and sometimes erroneous use of ''[[Has population::123456]]'' and ''[[population::123456]]''
I am still confused by the Berlin example.
- When you say:
The annotation avoiding ambiguity is as follows: Germany's capital is called [[Has capital::Berlin]]. ↔ [[Is capital of::Berlin]] is the capital of Germany.
- Are you saying that we're going to create two distinct properties
- Has capital
- Is capital of
- Perhaps it's my ignorance of the precise meaning of the symbol: "↔"
- Perhaps you're saying Property names should follow the expected usage, the expected context.
- Perhaps you're saying something else altogether.
indeed sometimes this wiki uses "Has population" and sometimes "Population". This should be consistent. I thought that I tracked all of them but obviously I did not. I recommend to use a more distinct naming scheme following the expected context.
The example the Berlin just explains that two distinct properties have to be created in case you would like to cater for the expected context. Both properties take Berlin as a value, but the meaning conveyed by the property is different in both cases. The symbol "↔" may best be seen here as a replacement for "compared to".
In case you want to avoid having two different properties you would just call it "Capital". Both properties mentioned above will probably never be used on the same page, so doing "Capital" is arguably a valid solution, too. I personally follow the two properties scheme here since this proved to be the better solution for me. Again, there are other opinions around, too.
Indeed, I was confused about this as well. Or more specifically, the information on the page is confused about this.
- It specifically uses [[Has population::1,234,567]] in the example.
- But then links in the text below points to Property:Population to define this property, and not Property:Has population.
The "property nomenclature" discussion is important. However, it also seems to throw new users off -- especially when the manual itself is not consistent about this. If the very page that tells a user how to name properties can't even do it right itself, then how are users expected to get it right.
Would the original authors object strongly if I re-structured the text a little, maybe emphasising practical examples at the top and postponing the "property nomenclature" discussion/recommendation until after the user has been given a change to grasp the basic concept of properties? I'm also thinking of add a note to mention that the "has" verb is not special: "has population" and "population" does not describe the same property. "Has" is used to produce a property that is better distinguishable from the other interpretations of this property. E.g. for the property "wife":
- "has wife" --> Relation. Barrack has wife Michelle. (Although for programmers this might be even less clear, as is could also be a boolean, whether or not Barrack "has (a) wife".)
- "is wife of" --> Relation. Michelle is (the) wife of Barrack.
- "is wife" --> Boolean. Michelle 'is (a) wife'.
- Category: Wife or Wives. Putting Michelle in the category of (known/famous) wives. Similar to "is wife" above, but the category might also include e.g. dictionary categorization, etc).
In the end, what matters is that properties are named and used consistently. Using the "has" verb prefix to make properties with a clear meaning is one way to help obtain that.
One might add that specifying both "has wife" and "is wife of" is redundant and against the "wikipedia" philosophy of centralizing the information and avoid repeating/scattering the information. In the context of semantic wiki, it might be better to use an inverse property instead of specifying both, e.g. use "-has wife" in place of "is wife of". (That discussion is, of course, beyond the scope of the present page.)