Individuals and properties in semantic web

Question

I'm currently working on a semantic web e-learning project. I've made an ontology and classes. However, when populating RDF files, I create an individual (for example a course) and place it in a RDF. Afterwards if I it is needed to relate another individual to this one by an object property (e.g. student-> studyMemberOf-> course), I put course Uri in student individual. This means (course individual Uri: crs000021):

<Ontologyowl:Student rdf:about="ehsanm">
    <Ontologyowl:studyMemberOf>
        <Ontologyowl:Project rdf:about="crs000021"/>
    </Ontologyowl:studyMemberOf>

I have 2 Questions here:
Is it right to put individuals of each class, in a separate RDF file?
When relating these two individuals, am I making another node of 'course (crs000021)' in student file? is this method (making different rdfs) incorrect?

Thank you for your attention

Answer 1

There is no specification about how and where you should write your RDF statement. You can write all the statements in the same file or each statement in one file. Moreover a RDF store should ignore every duplicated statements, so

<ehsanm> <studyMemberOf> <crs000021>
<crs000021> rdf:type  Ontologyowl:Project
<student2> <studyMemberOf> <crs000021>
<crs000021> rdf:type  Ontologyowl:Project

is the same as

<ehsanm> <studyMemberOf> <crs000021>
<crs000021> rdf:type  Ontologyowl:Project
<student2> <studyMemberOf> <crs000021>

Note: I'm not sure rdf:about="ehsanm" is a valid URI. I guess you should use rdf:ID here