The 5 Stars of Linked Open Data

★	Available on the Web (whatever format) but with an open licence, to be Open Data
★★	Available as machine-readable structured data (e.g. excel instead of image scan of a table)
★★★	as (2) plus non-proprietary format (e.g. CSV instead of Excel)
★★★★	All the above plus, Use open standards from W3C (RDF and SPARQL) to identify things, so that people can point at your stuff
★★★★★	All the above, plus: Link your data to other people’s data to provide context

Originally developed by Tim Berners-Lee

★ Available on the web

Usually means PDF, or worse, a screenshot of something.

You need to be a (sighted) human to access the information.

★ Available on the Web

★ ★ Available as machine-readable structured data

★ ★ Available as machine-readable structured data

Screenshot of the code behind the Excel sheet

★ ★ ★ Non-proprietary format

CSV* is King:

easy to export from Excel etc.
easy to serialise in JSON (developers' preferred format).
easy to understand and manipulate.

* Comma Separated Variables

★ ★ ★ Non-proprietary format

An excellent example of what can be done with 3 star data.

 SHA	PCT	PRACTICE	BNF CODE	BNF NAME                                    	ITEMS  	NIC        	ACT COST   	QUANTITY	PERIOD
Q30	5D7	A86003	0101010G0AAABAB	Co-Magaldrox_Susp 195mg/220mg/5ml S/F   	18	52.24	48.71	10000	201206
Q30	5D7	A86003	0101010N0AAAAAA	Antacid/Oxetacaine_Oral Susp S/F        	1	97.42	89.77	300	201206
Q30	5D7	A86003	0101010R0AAABAB	Simeticone_Susp 40mg/ml S/F             	2	4.9	4.58	100	201206
Q30	5D7	A86003	0101021B0AAAHAH	Gppe Liq_Gaviscon S/F                   	2	4.45	4.17	1000	201206
Q30	5D7	A86003	0101021B0AAALAL	Sod Algin/Pot Bicarb_Susp (Aniseed) S/F 	3	11.8	10.97	1300	201206
Q30	5D7	A86003	0101021B0BCAAAC	Gastrocote_Tab                          	2	14.04	13	400	201206
Q30	5D7	A86003	0101021B0BEADAJ	Gaviscon Infant_Sach 2g (Dual Pack) S/F 	6	65.78	60.79	330	201206
Q30	5D7	A86003	0101021B0BEAIAL	Gaviscon Advance_Liq (Aniseed) S/F      	14	85.8	79.49	9450	201206
Q30	5D7	A86003	0101021B0BEAKAQ	Gaviscon Advance_Liq (Peppermint) S/F   	11	55.76	51.71	5850	201206
Q30	5D7	A86003	0101021B0BEAQAP	Gaviscon Advance_Tab Chble 500mg Mint   	4	21.76	20.17	480	201206

★ ★ ★ Non-proprietary format

An excellent example of what can be done with 3 star data.

★ ★ ★ ★ Use open standards from W3C to identify things, so that people can point at your stuff

http://data.ordnancesurvey.co.uk/id/postcodeunit/IP45TW

screenshot of Ordnance Survey page about IP4 5TW

★ ★ ★ ★ Use open standards from W3C to identify things, so that people can point at your stuff

http://business.data.gov.uk/id/company/04285910

<rdf:RDF xmlns:cs0="http://www.companieshouse.gov.uk/terms/"
         xmlns:foaf="http://xmlns.com/foaf/0.1/"
         xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description rdf:about="http://data.companieshouse.gov.uk/doc/company/04285910#RegAddress">
    <cs0:Postcode>CO11 1UN</cs0:Postcode>
    <cs0:County>MANNINGTREE ESSEX</cs0:County>
    <cs0:AddressLine2>DALE HALL INDUSTRIAL ESTATE</cs0:AddressLine2>
    <cs0:PostTown>LAWFORD</cs0:PostTown>
    <cs0:AddressLine1>17 RIVERSIDE AVE WEST</cs0:AddressLine1>
  </rdf:Description>
  <rdf:Description rdf:about="http://business.data.gov.uk/id/company/04285910">
    <cs0:IncorporationDate>12/09/2001</cs0:IncorporationDate>
    <cs0:Returns rdf:resource="http://data.companieshouse.gov.uk/doc/company/04285910#Returns"/>
    <cs0:CompanyName>APPLE BINDING LTD</cs0:CompanyName>
    <cs0:SICCodes rdf:resource="http://data.companieshouse.gov.uk/doc/company/04285910#SICCodes"/>
    <cs0:Address rdf:resource="http://data.companieshouse.gov.uk/doc/company/04285910#RegAddress"/>
    <cs0:Accounts rdf:resource="http://data.companieshouse.gov.uk/doc/company/04285910#Accounts"/>
    <cs0:CompanyNumber>04285910</cs0:CompanyNumber>
    <cs0:CompanyStatus>Active</cs0:CompanyStatus>
    <cs0:CountryOfOrigin>United Kingdom</cs0:CountryOfOrigin>
    <cs0:CompanyCategory>Private Limited Company</cs0:CompanyCategory>
  </rdf:Description>
…
</rdf:RDF>

★ ★ ★ ★ Use open standards from W3C to identify things, so that people can point at your stuff

Why is

http://business.data.gov.uk/id/company/04285910

better than

 SHA	PCT	PRACTICE	BNF CODE	BNF NAME                                    	ITEMS  	NIC        	ACT COST   	QUANTITY	PERIOD
Q30	5D7	A86003	0101010G0AAABAB	Co-Magaldrox_Susp 195mg/220mg/5ml S/F   	18	52.24	48.71	10000	201206

★ ★ ★ ★ Use open standards from W3C to identify things, so that people can point at your stuff

Why is

http://business.data.gov.uk/id/company/04285910

better than

 SHA	PCT	PRACTICE	BNF CODE	BNF NAME                                    	ITEMS  	NIC        	ACT COST   	QUANTITY	PERIOD
Q30	5D7	A86003	0101010G0AAABAB	Co-Magaldrox_Susp 195mg/220mg/5ml S/F   	18	52.24	48.71	10000	201206

(Because you can look it up; because you can refer to a URI in any context, unlike 'Q30' which only means something in a specific context).