information architecture – Task vs object focused IA and navigation

As usual, it depends

It’s true that task-centered UI structures can better fit the user’s mental model of the task, but object-centered UI structures can better fit the user’s mental model of the objects (e.g., what belongs to what). Thus, object-centered UI structures are preferred when the user is primarily studying or appraising the content mentally, rather than following the steps of a task.

Task-centered UI structures tend to follow a dialog model between user and app, with the app in the role of an agent that the users communicate with. This can make the user feel they have indirect control over the content. Object-centered UI structures lend themselves better to direct manipulation so the user feels more in control, which can enhanced the user experience.

Object-centered UI structures tend to be preferred when:

  • The user is an expert on the tasks, or app is frequently used, or the user is trained on it; that is, the UI doesn’t have to lead the user by the hand through a task.
  • The app involves continuous dynamic interaction with the content, pausing and re-starting tasks, perhaps working on several tasks and/or objects at once, rather than completing an atomic interaction of one task on one object before doing anything else.
  • The tasks are complex, requiring user flexibility and creativity, involving selecting and combining a set of simple actions to achieve complicated results, rather than following a rigid linear procedure.
  • There are a relatively large number of tasks.

Enterprise management apps and dashboards

A dashboard app pretty much by definition has an object-centered UI structure, with a set of objects and their statuses (attributes) shown on the main window that users mentally appraise, and where they may drilldown for more details by selecting an object or attribute in the dashboard.

Enterprise management apps are generally best with object-centered UI structures, since they tend to involve a continuous series of complex tasks by expert users who use the app daily. However, if you have a group of users that rarely need to interact with the enterprise management app, and only need to do so for a few simple linear tasks, you may want to create a separate task-centered UI just for those users. A kiosk for customers is one example.

Of course, you can have a hybrid UI. For example, you could have an object-centered UI structure to support common tasks, but have a couple menu items to launch wizards to do rarely done tasks.

Menu structure does not necessarily equal UI structure

The parts of speech of the pulldown or sidebar menu does not necessarily indicate the UI structure. The UI structure defines the pages/windows and how they relate to each other. Thus, only the navigation menu items (if any) imply the structure. A menu can include other commands than navigate (e.g., verbs like copy and delete), but that doesn’t necessarily make the app a task-centered UI structure. What matters is what the pages/windows represent. Does each represent one or more objects? Or does each represent whole or part of a task?

Articles

For a contrary position to your UX Mastery link, see this article on Microsoft’s Inductive User Interface (which are task-centered UI structures). For detailed analysis supporting my “no, it depends” viewpoint, see my article Task-centered Versus Object-centered UI Structures.