Primer comments: editorial

I think the primer is much improved, hope to get a chance for a real  
review later - here are some comments on the profiles section - I  
consider these all to be editorial, as none of them change anything  
technical in the design or the descriptions thereof:

----
OWL EL:
The first paragraph says

> OWL 2 EL makes a good approximation target, that is, by only a  
> little simplification one can get an OWL 2 EL ontology and preserve  
> much of the meaning of the original ontology.


given that "good approximation target' is hard to understand, and is  
thus immediately explained, maybe this would make the strength of OWL  
2 EL clearer if it dropped the subclause and read:

"For many large, class-expression oriented ontologies, by only a  
little simplification one can get an OWL 2 EL ontology and preserve  
the bulk of the meaning of the original ontology."

which I think more clearly empohasizes this strength of EL.

-----

The primer says of OWL EL

> Not only does it scale well for facts and axioms, but it scales well  
> for complex expressions.


I think that second clause is too imprecise, because in profiles we  
say "OWL 2 EL places restrictions on the type of class restrictions  
that can be used in axioms."

which would seem to be contradictory.  I suggest either removing the  
sentence above, or coming up with a more technically correct way of  
saying "complex expressions" to avoid sounding self-contradicting.

-----
OWL QL

I thought this section was good, one nit:
   it says "can be realized on top of standard relational database  
technology" - where "on top of" seems to me to be unclear - maybe  
"...can be realized using standard relational database technology"   
would be clearer?

----
OWL RL


contrast this from QL

> Among other constructs, OWL 2 QL disallows existential  
> quantification of roles to a class expression, i.e. it can be stated  
> that every person has a parent but not that every person has a  
> female parent. Moreover property chain axioms are not supported.

with this from the RL

> One downside of OWL 2 RL is that it cannot express that the  
> existence of an individual enforces the existence of another  
> individual: for instance, the statement “every person has a parent”  
> is not expressible in OWL RL.

Why are we calling this a "downside" for RL, but simply stating it as  
an aspect of the language for QL (and there is similar in EL) ?  I  
would suggest we reword the RL one to be more like the one in QL - i.e

"Among other constructs, OWL 2 RL disallows statements where the  
existence of an individual enforces the existence of another  
individual: for instance, the statement “every person has a parent” is  
not expressible in OWL RL."

Also, in RL it says:

> Suitable rule-based implementations of OWL 2 RL will have desirable  
> computational properties; for example, they can return all and only  
> the correct answers to certain kinds of queries. Such an  
> implementation can also be used with arbitrary RDF graphs. (In this  
> case, however, these properties no longer hold – in particular, it  
> is no longer possible to guarantee that all correct answers can be  
> returned.)


which is correct, but I think confusing (just in the use of the  
English) - I'd suggest in this case the technical vocabulary might be  
more useful - how about:

"Suitable rule-based implementations of OWL 2 RL will have desirable  
computational properties; for example, they are sound and complete  
with respect to many kinds of queries. OWL 2 RL can also be used with  
arbitrary RDF graphs., however in this case, as with OWL Full, there  
may be cases where completeness cannot be guaranteed. "


Again, I think the section here is very useful, and consider these  
editorial suggestions that would not effect the LC status of the  
documents
   -JH