In evaluating OSIS, we conduct six sets of experiments: comparing the ontology documents generated from GOSIS and SOSIS design candidates with three frames of reference. The indicators are selected from the category of Economy from the three frames of reference (the GRI, the OECD and the UN indicator sets). The experimental design consists has two phases:
1. Preparing the indicator sets’ metadata and populating the ontology design candidates.
2. Obtaining the overlapping terms with the original documents.
4.5.1 Preparing and Analysing Sustainability Indicator Sets Metadata
The GRI organisation uses XBRL language to define its sustainability metadata in a tax-onomy. This structured hierarchy captures the individuals reporting concepts as well as the relations between concepts and other semantic meanings in the original document.
Experiments 90 materials used that are recycled input materials. (Core)</label>
4 <label xlink:type="resource" xlink:label="gri-core_EN02_lbl_en_protocolRelevance"
xlink:role="http://www.globalreporting.org/2006/G3/protocolRelevance"
xml:lang="en" id="gri-core_EN02_lbl_en_protocolRelevance">This Indicator seeks to identify the reporting organization’s ability to use recycled input materials. Using these materials helps to reduce the demand for virgin material and contribute to the conservation of the global resource base. For internal managers and others interested in the financial condition of the reporting organization, substituting recycled materials can contribute to lowering overall costs of operation.</label>
5 <label xlink:type="resource"
xlink:label="gri-core_EN02_lbl_en_protocolCompilation"
xlink:role="http://www.globalreporting.org/2006/G3/protocolCompilation"
xml:lang="en" id="gri-core_EN02_lbl_en_protocolCompilation">2.1 Identify the total weight or volume of materials used as reported under EN1. 2.2 Identify the total weight or volume of recycled input materials. If estimation is required, state the estimation methods. 2.3 Report the percentage of recycled input materials used by applying the following formula: EN2 = (total recycled input materials used/ input materials used ) x 100% </label>
6 <label xlink:type="resource"
xlink:label="gri-core_EN02_lbl_en_protocolDocumentation"
xlink:role="http://www.globalreporting.org/2006/G3/protocolDocumentation"
xml:lang="en" id="gri-core_EN02_lbl_en_protocolDocumentation">Potential information sources include billing and accounting systems, the procurement or supply management department, and internal production and waste disposal records. </label>
7 <label xlink:type="resource"
xlink:label="gri-core_EN02_lbl_en_protocolDefinition"
xlink:role="http://www.globalreporting.org/2006/G3/protocolDefinition"
xml:lang="en" id="gri-core_EN02_lbl_en_protocolDefinition">Recycled input materials. Materials that replace virgin materials that are purchased or obtained from internal or external sources, and that are not by-products and non-product outputs (NPO) produced by the reporting organization. </label>
8 <label xlink:type="resource" xlink:label="gri-core_EN02_lbl_en_protocolReference"
xlink:role="http://www.globalreporting.org/2006/G3/protocolReference"
xml:lang="en" id="gri-core_EN02_lbl_en_protocolReference">- OECD Working Group on Waste Prevention and Recycling.</label>
Table 4.6: An Example of GRI Indicator (EN2) in XBRL format
Experiments 91
1 # NTriple generation by
2 # notation3.py.v 1.148
3 # <Subject> <Predicate> <Object>
4 <EN2> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <GRI_Indicator>.
5 <EN2> <http://pur1.org/dc/elements/1.1/isReferencedBy> <EN2-Reference>.
6 <EN2> <http://pur1.org/dc/elements/1.1/title> "Percentage of materials used that are recycled
7 input materials".
8 <EN2>
<http://www.cs.rmit.edu.au/knowlodgebase/ontology/OSIS/hasUnitOfMeasurement>
"percentage".
9 <EN2> <https://www.g1oba1roporting.org/hasAspect> <EN2-Aspect>.
10 <EN2> <https://www.g1oba1roporting.org/hasRelevance> <EN2-Relevance>.
11 <EN2> <https://www.g1oba1roporting.org/hasCompilation> <EN2-Compilation>.
12 ...
13 <EN2-Aspect> <http://pur1.org/dc/elements/1.1/title> "Environment"
14 <EN2-Relevance> <http://pur1.org/dc/elements/1.1/text> "This Indicator seeks to identify the reporting organization’s ability to use recycled input materials. Using these materials helps to reduce the demand for virgin material and contribute to the conservation of the global resource base. For internal managers and others interested in the financial condition of the reporting organization, substituting recycled materials can contribute to lowering overall costs of operation.".
15 <EN2-Compilation> <http://pur1.org/dc/elements/1.1/text> "2.1 Identify the total weight or volume of materials used as reported under EN1. 2.2 Identify the total weight or volume of recycled input materials. If estimation is required, state the estimation methods. 2.3 Report the percentage of recycled input materials used by applying the following formula: EN2 = (total recycled input materials used/ input materials used ) x 100% ".
Table 4.7: An Example of GRI Indicator (EN2) in NTriples format
Experiments 92
To prepare and analyse the GRI XBRL, we phrase the required data from this docu-ment using SAX functions including: start-docudocu-ment, start-eledocu-ment, end-eledocu-ment, character and end-document. These functions are applied to the label tags with con-ditioning the relevant attributes such as id, xlink:type and xlink:label. An example of a GRI indicator from the Environment category and its XBRL representation are shown in Table 4.6.
On the other hand, the OECD organisation does not present its indicators in a struc-tured or semi-strucstruc-tured format. The hierarchy of indicators and associated information is represented in a pdf document. In order to use the OECD indicators, we first organise the dataset into an Excel document. Next, we convert the Excel document into a XML structure, defining an XML schema for the OECD dataset using the hierarchy structure and extracted key terms from the original dataset such as group, theme, topic, measurability and descrip-tion. An example of OCED indicator and its XML code after the conversion are shown in Figure 4.3 and Table 4.8 respectively.
During this phase, the two design ontologies are populated through the use of the Prot´eg´e ontology editor by the structured information extracted from the GRI and OECD datasets.
Finally, we export the RDF format from the final ontology documents in Prot´eg´e editor.
An example of the generated file in N T riples8 is shown in Table 4.7. It shows the triple statements consisting of subject, predicate and object representing the same key information of EN 2 shown in Table 4.6 using relevant namespaces, concepts and appropriate relationships in the GOSIS design. The relations in the ontology are shown in blue, such as description, format and isReferencedBy.
4.5.2 Obtaining the Overlapping Terms
The final step in performing the experiments is obtaining the overlapping terms between the original frames of reference and the ontology documents. To produce consistent results, a pre-processing stopping algorithm and Porter’s Stemmer technique [Porter, 1997] were applied to the original documents. We then used the algorithm presented by Broder [2000],
8http://www.w3.org/2001/sw/RDFCore/ntriples/
Experiments 93
10 <Issue>The estimates are affected by the quality of the underlying energy data.</Issue>
16 The very high per capita emissions of Luxembourg result, to a
large degree, from the lower taxation of gasoline and diesel oil compared to neighbouring countries.
17 </Measurability>
18 <Desription>
19 Production-based CO2 emissions from fuel combustion Emissions
calculated using IEA energy databases and the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories. For example, some countries, both OECD and non-OECD, have trouble reporting information on bunker fuels and incorrectly define bunkers as fuel used abroad by their own ships and planes....
20 </Desription>
Table 4.8: An Example of OECD Indicator in XML format
Results 94
which determines the syntactic similarity between two documents. The first document was the textual representation of the ontology, and the second was the frames of reference. Each document is considered as a sequence of tokens, divided into contiguous subsequences called shingles, of length n, that is also known as n-gram. Broder [2000]’s algorithm compared the sets of n-grams from two documents and calculates their resemblance value.