Feedback on assignment 3

[csarven]

3.1. You are missing the subject resource for the statements. What are these about?

3.2 You are generally in the right direction. Make sure to create triple patterns. Some parts of the triple pattern (s,p,o) you may know or not know. If you don't know, that's a variable, right?

The URI for Switzerland is already given in the exercise for both queries (and they are different), you don't need to filter the country to country:CH, you already know it! Similarly, you don't need to use the literal "Switzerland" in the query. Using is not wrong per se, but it could lead you to something you don't want. For example, what you are looking for is something with foaf:name "Switzerland". While we usually think of that as country, it may be anything! So, you need to add other qualifiers..

Finally, you need to use a federated query (a single query which fires off two separate queries). See the slides for one particular example (at least the skeleton). See also SERVICE at http://www.w3.org/TR/sparql11-federated-query/

[csarven]

re what you wrote at #4 (comment)

Exercise 3, I made some improvement. I am still not sure if the federated query (SERVICE) is ok like I wrote it down.

You are close, but it just needs to be wrapped up to a single query. So, you should have a single SELECTat the top and then it makes two SERVICEs which are inside the WHERE. Don't forget to return the GDP value for the first query.

[csarven]

Also, I don't think you've addressed what I said about the Switzerland URI in the first comment (above).

[Sargd1]

Exercise 3, I added the GDP value . About the Switzerland URI, I wrote foaf:name "Switerland" is it alright like that?I now have a single SELECT at the top and two SERVICE'S inside the WHERE.