Task Oriented Design

Article published on December 16, 2005 under User centered design

Let start from one design principle: increase efficiency and flexibility of use providing accelerators for expert people or allowing users to tailor frequent actions.

Task oriented design (TOD) can be used to provide a methodology useful to plan and develop interfaces that can improve interaction between users and system. Supporting multiple interfaces based on user workflow, users role or user proficiency can enhance system not only in terms of usability but also in terms of profitability, increasing revenues from frequent actions.

An example

We can prove it considering a simple web application that can be used to browse the catalog of a video rental shop. In such environment we can define two types of actors:

  • customers that interact with frontend and are occupied by browsing catalog searching for particular titles or movie genres
  • content managers that interact with backend and spend most of their time adding more titles and information to the application

A typical backend interface shows to content managers a list of published movies entries ordered by title as we can see in the following image:

List of published movies

List of published movies

Content managers in order to add a new title had to click to add movie link and then fill up a form with all movie informations:

Add a movie

Add a movie

To achieve the operation content managers had to perform two mouse clicks (we will not consider mouse clicks used to jump from one field to another): one for accessing the "add movie" interface and the second for submitting informations. In most cases content managers need to add more than one movie title, so considering 20 items to be integrated in the application brings to a total of 40 mouse clicks to complete the task.

Is time now to use task oriented design for interaction. First of all we have to perform a simple operation: add a movie title to the system. As the operation suggest we have to use the "add movie" interface as default. When informations are submitted, system reloads the page and provide feedback needed to evaluate operation results. Such change in system flow increase speed of add operation because mouse clicks pass from 40 to 20.

The methodology

Task oriented design focuses on real task that can be used to engineering specific interfaces that can improve interaction between system and users. To apply such methodology we have to follow these simple steps:

  • Requirements analysis
  • Analyze system actors and divide them in categories based on user role, proficiencies accessibility and patience.
  • Analyze system environment in order to distinguish if task oriented design is really needed and can improve user interaction.
  • Analyze task that had to be performed by actors using HTA.
  • Analyze system information flow to avoid logic inconsistencies.
  • Prototyping
  • Review existing interfaces. Instead of creating new ones is faster and cheaper reuse existing interfaces by changing the order which are presentend.
  • Create mock-up and prototypes to simulate system functionality.
  • Deploy phase
  • Test system with real users and evaluate their impressions about functionality.
  • Evaluate usage in mid term and long term period in order to find improvements cues.

Conclusions

Task oriented design can be used to improve efficiency and flexibility of systems by the analysis of real and representative task performed by users. In order to enjoy of task oriented design, system had to be analyzed taking in consideration actors, tasks and eventually reviewing existing interfaces. Evaluating usage of real users in long term can be useful to find improvements cues and become a repository of best practices in case of design reuse.