Protege Tutorial for MMI
Motivation
The MMI workshop in August 2005 will focus on developing mappings between existing marine metadata vocabularies, and making those mapped vocabularies available to users via web services. Most of the work of the meeting will be performed in small, carefully organized breakout teams, oriented around specific domains. To choose the domains, we created an ontology in Protege about "marine things". This tutorial describes how to open this ontology for review. (The same process will allow the user to open any ontology represented in the OWL format.)
Prerequisites
- Broadband internet connection
- Ontology Background. If not a 2 page introduction can be found at: http://dspace.library.drexel.edu/retrieve/3122/ch2.pdf. A more comprehensive ontology tutorial can be found here.
- Protege 3.1b must be installed in your computer. If not then download Protege. The download page is http://protege.stanford.edu/download/download.html. We recommend version 3.1b FULL (as of 2005.04.13). It has new features that we use in the ontology. Follow the instructions and make a full installation.
Steps To Open the MMI domain ontology
| Run protege. A folder with protege_3.1_beta should have been installed. Look for Protege application (an executable) and click on it. You will see the following display: |
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| Click on "Create New Project". You will see the following form: |
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| Select on "create from existing sources" and click on next. You will see the following window: |
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| Write the following URL in the "OWL file name or URL" field: http://marinemetadata.org/2005/04/mmidomains. (If you are a Macintosh user and do copy/paste, use the ctrl key + 'c' (copy) or 'v' (paste). |
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| Click on the "Finish" button. Wait approximately one minute until all the domain knowledge based is loaded into your computer memory. |
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Click on the bottom right part of the window and select Properties View. At this point in the Protege application the MMI domain ontology and all the ontologies that are imported form that ontology are loaded into the program in your cache memory. You can save a copy of this ontology in your computer. Click on file/save project. Two files will be saved in the location indicated: the *.owl file and a *.prog file. The first one is the ontology, the second one is the project file that is used by Protege to store information about the created project. However only the main ontology will be stored the imported ontologies are not saved. If you need to see the new posted version of the ontology you need to go through all the steps again. |
What is what ?
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The MMI domain ontology is based on OWL (if not familiar then read the tutorial recommended in the prerequisites section). We will use the term resources to refer to classes, properties and individuals.
Classes view
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 Click the image for a larger view |
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Protege has various tabs to present thee different views of an ontology. For example it has OwlClasses, properties and individuals tabs. The first one OwlClasses shows the classes hierarchy and the properties assigned to each class. You can also see which classes are from an imported ontology and which one is not because the later representations showed up with a grayed icon.
Individuals view
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| In this view you also have the class hierarchy, plus two additional frames. The middle one shows the list of all individuals of a particular class and the right one shows all the properties of a selected individual. |