Author here, ask me anything! Slides are also available at <a href="http://www.slideshare.net/_Emw/an-ambitious-wikidata-tutorial" rel="nofollow">http://www.slideshare.net/_Emw/an-ambitious-wikidata-tutoria...</a>.
Good tutorial! Wikidata is an awesome initiative for Wikimedia and I would love to see all Wikipedia's structured data powered by wikidata. Wikidata is much easier to interface with than wikipedia infoboxes!
Wikidata's new SPARQL service is probably the most useful topic in this tutorial for software developers and anyone interested in the Semantic Web. It allows one to query the vast, free knowledgebase that backs Wikipedia -- almost 15 million entities and over 70 million statements.<p>Example queries:<p>* Politicians who died of cancer (of any type): <a href="https://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3A%2F%2Fwikiba.se%2Fontology%23%3E%0APREFIX%20wd%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%20%0APREFIX%20wdt%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fdirect%2F%3E%0APREFIX%20rdfs%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0A%0ASELECT%20%3Fpolitician%20%3Fcause%20%3Fpolitician_label%20%3Fcause_of_death_label%20WHERE%20{%0A%20%20%20%3Fpolitician%20wdt%3AP106%20wd%3AQ82955%20.%20%20%20%20%23%20find%20items%20that%20have%20%22occupation%20%28P106%29%3A%20politician%20%28Q82955%29%22%0A%20%20%20%3Fpolitician%20wdt%3AP509%20%3Fcause%20.%20%20%20%20%20%20%20%23%20with%20a%20P509%20%28cause%20of%20death%29%20claim%0A%20%20%20%3Fcause%20wdt%3AP279*%20wd%3AQ12078%20.%20%20%20%20%20%20%20%20%23%20...%20where%20the%20cause%20is%20a%20subclass%20of%20%28P279*%29%20cancer%20%28Q12078%29%0A%20%20%20%23%20%3Fpolitician%20wdt%3AP39%20wd%3AQ11696%20.%20%20%20%23%20Uncomment%20this%20line%20to%20include%20only%20U.S.%20Presidents%0A%20%20%0A%20%20%20OPTIONAL%20{%3Fpolitician%20rdfs%3Alabel%20%3Fpolitician_label%20filter%20%28lang%28%3Fpolitician_label%29%20%3D%20%22en%22%29%20.}%20%0A%20%20%20OPTIONAL%20{%3Fcause%20rdfs%3Alabel%20%3Fcause_of_death_label%20filter%20%28lang%28%3Fcause_of_death_label%29%20%3D%20%22en%22%29.}%0A}%0AORDER%20BY%20ASC%20%28%3Fpolitician%29" rel="nofollow">https://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3...</a><p>* Who discovered the most planets? <a href="https://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3A%2F%2Fwikiba.se%2Fontology%23%3E%0APREFIX%20wd%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%20%0APREFIX%20wdt%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fdirect%2F%3E%0APREFIX%20rdfs%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0A%0ASELECT%20%3Fdiscoverer%20%3Fname%20%28COUNT%28DISTINCT%20%3Fplanet%29%20as%20%3Fcount%29%0A%20WHERE%20{%0A%20%20%20%3Fppart%20wdt%3AP279*%20wd%3AQ634%20.%0A%20%20%20%3Fplanet%20wdt%3AP31%20%3Fppart%20.%0A%20%20%20%3Fplanet%20wdt%3AP61%20%3Fdiscoverer%20.%0A%20%20SERVICE%20wikibase%3Alabel%20{%0A%20%20%20%20bd%3AserviceParam%20wikibase%3Alanguage%20%22en%22%20.%0A%20%20%20%20%3Fdiscoverer%20rdfs%3Alabel%20%3Fname%0A%20%20%20}%0A%20}%0A%20GROUP%20BY%20%3Fdiscoverer%20%3Fname%0A%20ORDER%20BY%20DESC%28%3Fcount%29%0A%20LIMIT%2010" rel="nofollow">https://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3...</a><p>* Largest cities with a female mayor: <a href="http://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3A%2F%2Fwikiba.se%2Fontology%23%3E%0APREFIX%20wd%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fentity%2F%3E%20%0APREFIX%20wdt%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fdirect%2F%3E%0APREFIX%20rdfs%3A%20%3Chttp%3A%2F%2Fwww.w3.org%2F2000%2F01%2Frdf-schema%23%3E%0APREFIX%20p%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2F%3E%0APREFIX%20q%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fqualifier%2F%3E%0APREFIX%20v%3A%20%3Chttp%3A%2F%2Fwww.wikidata.org%2Fprop%2Fstatement%2F%3E%0A%0ASELECT%20DISTINCT%20%3Fcity%20%3FcityLabel%20%3Fmayor%20%3FmayorLabel%20WHERE%20%7B%0A%20%20%3Fcity%20wdt%3AP31%2Fwdt%3AP279%2A%20wd%3AQ515%20.%20%20%23%20find%20instances%20of%20subclasses%20of%20city%0A%20%20%3Fcity%20p%3AP6%20%3Fstatement%20.%20%20%20%20%20%20%20%20%20%20%20%20%23%20with%20a%20P6%20%28head%20of%20goverment%29%20statement%0A%20%20%3Fstatement%20v%3AP6%20%3Fmayor%20.%20%20%20%20%20%20%20%20%20%20%20%23%20...%20that%20has%20the%20value%20%3Fmayor%0A%20%20%3Fmayor%20wdt%3AP21%20wd%3AQ6581072%20.%20%20%20%20%20%20%20%23%20...%20where%20the%20%3Fmayor%20has%20P21%20%28sex%20or%20gender%29%20female%0A%20%20FILTER%20NOT%20EXISTS%20%7B%20%3Fstatement%20q%3AP582%20%3Fx%20%7D%20%20%23%20...%20but%20the%20statement%20has%20no%20P582%20%28end%20date%29%20qualifier%0A%20%0A%20%20%23%20Now%20select%20the%20population%20value%20of%20the%20%3Fcity%0A%20%20%23%20%28wdt%3A%20properties%20use%20only%20statements%20of%20%22preferred%22%20rank%20if%20any%2C%20usually%20meaning%20%22current%20population%22%29%0A%20%20%3Fcity%20wdt%3AP1082%20%3Fpopulation%20.%0A%20%20%23%20Optionally%2C%20find%20English%20labels%20for%20city%20and%20mayor%3A%0A%20%20SERVICE%20wikibase%3Alabel%20%7B%0A%20%20%20%20bd%3AserviceParam%20wikibase%3Alanguage%20%22en%22%20.%0A%20%20%7D%0A%20%7D%20ORDER%20BY%20DESC%28%3Fpopulation%29%20LIMIT%2010" rel="nofollow">http://query.wikidata.org/#PREFIX%20wikibase%3A%20%3Chttp%3A...</a><p>More Wikidata SPARQL query examples: <a href="https://www.mediawiki.org/wiki/Wikibase/Indexing/SPARQL_Query_Examples" rel="nofollow">https://www.mediawiki.org/wiki/Wikibase/Indexing/SPARQL_Quer...</a>.