Activity Theory & Hierarchical Task Analysis

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1 Activity Theory & Hierarchical Task Analysis The Power Couple for Effective UX Analysis By Tobias Komischke, Ph.D. Created: March 15 th, 2013

2 Page 2 Intro UX design is about understanding behavior and designing UI solutions to support it. I guess any UX professional would agree that the analysis phase of a UX design project is crucial for the quality of the design. Activity Theory provides a framework to focus that analysis while Hierarchical Task Analysis provides a practical technique for executing it. Of course, there are many more frameworks, methods and techniques, but I find these two compelling because they are based on a similar paradigm. Activity Theory The Russian psychologist Aleksei Leontiev, founder of Activity Theory, postulated that human behavior can be broken down into 3 levels: Activities, Actions and Operations (see Figure 1). Figure 1. Activity Theory Pyramid. Activity An activity is the sum of all mental and physical processes that are directed towards accomplishing something. All activities are based on motives or needs. For example, I may drive to the airport to pick up a friend that I have not seen in a while. The activity is driving to the airport and the motive is to see that

3 Page 3 friend again and have a great time. Analyzing an activity requires understanding WHY something is being done. In UX design, we want to understand the user s motivation to interact with a product. Action Actions are the individual steps that need to be carried out in order to complete an activity. Different from an activity, the motive doesn t play a role here. The end goal is still to fulfill a need, but each action has its own goal that must be consciously attended to. In UX design terms, think of actions as tasks. Breaking down that trip to the airport reveals the actions that are involved. For example: Planning the route Filling the gas tank Driving to the highway ramp The individual goals of my actions are making sure that I use the fastest route to the airport, have enough gasoline, and getting on the right highway. The reason why I am driving to the airport is not relevant on this level. There could be dozens of motives other than picking up my friend. At the level of actions, all we care about is the WHAT. What am I doing to accomplish the activity of getting to the airport? Operation This is the execution level of an action. Operations don t have goals and they are executed frequently enough to become routine. In other words, they are more or less automated and are performed without paying attention. In my example, the action of filling the car s gas tank consists of removing the cap, selecting the grade, removing the nozzle, etc. Looking at operations helps answer the question about the HOW. How do I execute each action? How do I make things happen? For example, how do I fill the gas tank? Operations are bound to conditions under which their respective actions are being carried out. In other words, they are flexible. The quantity of gas I pump, for example, depends on how empty the tank is or how high the price is. Applying Activity Theory to UX Design Let s get back to UX design. What do we do now with these definitions? Well, Activity Theory helps us understand what to focus on during the analysis phase of a UX design project. For example, if somebody asks you for an alternative to specifying a date by entering numbers (mm/dd/yyyy) which is on the operational level, you can suggest a date picker without necessarily needing to know the action or the activity of which this operation is part. On the other hand, if you re developing the user experience of a novel product from scratch, understanding the activities that users will carry out with the product is

4 Page 4 essential, because you want to design something relevant and useful. If a stakeholder wants to know why you ask all those silly questions during your analysis, you can explain that asking about the WHY, WHAT and HOW serves a certain purpose. You may want to refrain from lecturing about Russian psychologists from last century though UX analysis has always been about getting answers for the "W questions (why, when, who, where, what). However, depending on the scope of the project (strategic vs. tactical), not all questions are similarly relevant. The behavioral levels introduced by Activity Theory provide a useful framework and vocabulary for determining what sort of information is necessary to make the right decisions for your project. Hierarchical Task Analysis Using Activity Theory as the framework to focus our understanding of the levels of (user) behavior during the analysis phase of a UX design project, we can now apply Hierarchical Task Analysis (HTA) as a practical technique for executing UX analysis. The foundations of HTA go back more than 100 years to people like Frederick W. Taylor. HTA is similar to Activity Theory in that it s about a top-down analysis and the decomposition of larger units into sub-units. The following conversation is a good analogy: Me, asking a pilot: So what do you do? Pilot: Well, I fly planes. Me: What does that involve? Pilot: Well, I do pre-flight stuff, I do the actual flying, and I do post-flight stuff. Me: What does the pre-flight stuff involve? You get the point. By always asking the same kind of question, you drill in more and more into the details. I ve found this structured way of understanding what somebody else is doing very helpful, especially in those projects where I haven t known the domain in advance. The hierarchical way of looking into behavior is very similar to Activity Theory, differing only in that it begins at the level of actions rather than activities.

5 Page 5 Here s an example of how to document the findings: Figure 2. Documentation of a Hierarchical Task Analysis. The plans (Need an overarching description of what the tree structure represents and why it s a useful way of describing the findings. The the last sentences of this paragraph. You also need a sentence defining what plans are. They are only introduced in the figure.) help to document sequences, conditions, etc. It s not a must to document those plans; it depends on the project. The above image only shows partial results. If you have analyzed all levels (Need definition of level) completely, the image looks like a pyramid (like the Activity Theory image in Figure 1). The top is the overall task. From this point, the tree branches out into higher-order subtasks, which, in turn, branch out into sub-subtasks, becoming increasingly granular until about it reaches the level of interactions (e.g., I push the throttle forward ). This representation of the data provides a natural progression from abstract to concrete, from tasks (Actions in the lingo of Activity Theory) to interactions (Operations in the lingo of Activity Theory). This is

6 Page 6 the strength of Hierarchical Task Analysis. It helps to overcome deer-in-the-headlight moments that occur when you are staring at piles of analysis results, but still don t know how to translate that knowledge into concrete design. Because Task Analysis provides a framework down to the level of an individual interaction, it helps make the translation from data to design rather straight-forward, because you can map operations to UX patterns. If you know that a user has to be provided a means to enter a date, there are reference UX solutions available. Tools like Quince can show you how. An additional benefit of HTA is that it provides a visual representation of the results that, like an organization chart, is easy to read and understand.