Can you quickly assign a super-class to a set of topics?

[clemp]

Thanks to your previous help I was able to explore a little further and discovered some of the useful tools for manipulating the data in Wandora.
Starting with the Directory/File Extractor, using the built-in tools in Wandora, I was able to:
- Set both Directory and File as Content Types
- Add File_Type as a new Occurrence type for File Topic
- Populate the FiIe_Type Occurrence with the file extensions for all instances of File.
- Convert the File_Type Occurrence to Associations between the file and the File_Type for all instances of File.
- In the process, Wandora created Topics for each file extension (pdf, txt, epub, jpg, etc)

However, the new topics (pdf, txt, epub, jpg, etc) are not yet sub-classes of File_Type.
Is there an easy way to select all the associations and tell Wandora to assign a super-class to all the Topics in a given Role?

Thanks,

Carl

[akivela]

Hi Carl

Sure it is possible, it is quite easy:

• First open the File_Type topic in topic panel. As the File_Type is an association type you should see a number of associations between file extensions and files.
• Select all rows of file extension column in the File_Type association table. It doesn't matter if several rows have same file extension topic.
• Right mouse click over the selection and choose context menu option Topics > Associations > Make subclass of current... The current refers here to a topic that is open in topic panel i.e. File_Type and operation target is the topic selection i.e. all topics in the file extension column.

And that is about it. Now you should see all file extension topics as subclasses of topic File_Type. If you wanted to use another association type and roles, you could continue in modifying these superclass-subclass associations with other tools from here.

Please drop a line if you had problems in following these steps.

Kind Regards,
Aki / Wandora Team

[clemp]

No problem with that but it does bring up a question about both Topic Maps and Wandora that might be harder to answer.
In the case of the relationship between the topic File_Type and the type of the file ( txt, pdf, etc), what are the trade-offs between creating a super-class/sub-class association and making the type of file an instance of the File_Type. I see that I can even configure the types of files to have both relationships at the same time.
Is there a preferred way to relate the topics and is there any drawback to defining both types of relationships for the same topic pair?
Thanks again for all your help.

Carl

[aki]

Well, now you are talking about information design and information modelling.

My personal opinion is that actual file types such as txt, pdf and doc are instances of the File_Type topic -- not subclasses. Therefore I would use only class-instance relations. But I totally understand if you want to use superclass-subclass relations instead. But I wouldn't use both class-instance and superclass-subclass relations to model the same thing. It duplicates the information and the information is difficult to maintain in the long run. Also, it is probably confusing since class-instance and superclass-subclass relations have both a commonly known and different meaning.

Generally speaking, Wandora doesn't restrict the associations nor relations you set up between topics. It is purely user's design choice -- and responsibility to build an information structure she can live with. However, it is our goal in designing the Wandora application that the user can easily change the information structure when she wants -- to whatever she wants.

Kind Regards,
Aki / Wandora Team