Ontology provides a specification of a domain. User interfaces of a system has to show the contents (objects, actions and relationships between them) of a domain to the users. So, an ontology can be used as a conceptual model in conceptual modelling stage of interaction design process to specify the domain and what need to be included in user interfaces.

Therefore, I taught my students to create conceptual models based on ontology concepts (showing domain concepts, relationships between the domain concepts (inclusion relations/kind of, meronymic relations/ part-of, etc.) and constraints such as cardinality restrictions) in creating a conceptual design for interfaces.

What did it look like?

This provides a basic idea of applying ontological principles to build a concepual model using a simple example for an airline system that can eventually be used to design user interfaces. An interface can include several domain objects (e.g.: Flight, Airline and Passenger in a flight booking system), a number of actions (e.g.: enter search criteria, search flights, select flights, book flights, enter passenger details, make payments, etc.) and how these actions are related to domain objects (e.g.: search flights, select flights and book flights are related to flights). Once an ontology-based conceptual model is developed it becomes easy to map the conceptual model to user interfaces. This example mainly show using inclusion (kind-of or type-of) relations.

  1. A conceptual model includes objects, functions/ actions and relationships (figure 1).
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Figure 1: Main parts of a conceptual model

  1. We can specify a flight booking system as a conceptual model using some ontology concepts (figure 2).
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Figure 2: Initial conceptual model for a flight booking system.

  1. Some of the concepts/objects in a flight booking system can be shown in the initial conceptual model as follows (figure 3). It includes the objects flight, passenger and airline as different types of concepts.
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Figure 3: Some concepts/objects in a flight booking system.

  1. Some of the functions/actions in a flight booking system can be shown in the initial conceptual model as follows (figure 4). It includes seven functions as different types of functions that the users can perform.
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Figure 4: Some functions/actions in a flight booking system.

  1. The concepts/objects and the functions/actions that are shown in the initial conceptual model can now be used to design user interfaces. Below (figure 5) is an initial wireframe for a user interface designed using Balsamiq (https://balsamiq.com/wireframes/ ) wireframe mock up application.
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Figure 5: A wireframe for a user interface of a flight booking system.

Similar to this meronymic / part-of relations can be applied to show the different interface components like labels, buttons, menus, images, hyperlinks, etc. of an interface. Again, those components become types of interface components as well.

The ontology principle constraints such as cardinality constraints can also be applied in this example. We can show how many flights a passenger can select at a time (depending on the type of flight booking, one-way, return or multi-city). Also, how many passengers can be added to a single booking could be restricted to a maximum number or the user could be directed for a group booking specially this feature is useful for travel agents.