"The attention economy brings with it its own kind of wealth, its own class divisions - stars vs. fans - and its own forms of property, all of which make it incompatible with the industrial-money-market based economy it bids fair to replace. Success will come to those who best accommodate to this new reality." --Michael H. Goldhaber http://www.firstmonday.dk/issues/issue2_4/goldhaber/

When a customer visits your website, you must make efficient use of their time and attention. In addition optimizing to the relationship between duration and likelihood of distraction, task demands need to be structured to be compatible with human cognitive systems. This principle is one of the key usability heuristics [Nielsen], a bit like one of the ten commandments for a usability professional. The heuristic is expressed a directive minimize memory load, but can also viewed as a directive to carefully manage task demands.

Task demands may be composed of the need to retrieve information from the environment or memory, make decisions, remember parts of the process, and maintain a goal structure or roadmap for the process. This is particularly relevant when their is competition for a person's attention. In this article, I will explore the relationship between task structure, the user's context and memory load, and the user's goals.

Goals start out at a high level, like buy a gift for my niece, and get translated into a series of subgoals like "find a gift" and "buy the gift". Subgoals get progressively smaller as the user interacts with process or artifact needed to accomplish their high level goal. These low level goals are a composite result of the user's previous experience with similar situations, the affordances (opportunities for action, [Norman]) presented, and general cognitive tendencies.

Conflicts between a user's goals and task structure result in abandoned tasks, forgotten steps, lost productivity, and lost revenue. These conflicts arise from semantics, common sense views of how the world works, as well as general characteristics of human cognitive systems. By exploring examples of mismatches, I hope to help you identify the cost of awkward task structures, how to recognize such structures, and how to fix them.

Consider the real world task of making copies. This top level goal is translated into "insert original in copy bay", optionally increase the quantity, start the copying, and remove the copies and the original. People sometime forget that last step, remove the original. The source and conditions under which this error occurs has been pondered for some time in psychological inquiry, but the issue is becoming less tangled. High memory load, a measure of task demands, seems to be a key determinant of when this error occurs [Byrne & Bovair, 1995]. This makes sense intuitively -- you're more likely to forget things when you are worried about other topics or are interrupted while completing a task.

This type of error, however, is indicative of another general cognitive principle. Top level goals help sustain subgoals in cognitive systems and protect them from forgetting or subjugation to other distractions. Leaving the original in a copier points out the lack of match between user goals and the task structure. When the user removes the copies from the tray the top level goal is satisfied, removing it from it's role as the sustainer of subgoals. A related scenario is the use of an automated teller machine. Typically, your goal is to get money. But, even after the money is released, there is often one more thing to wait around for -- the return of your banking card. Thus, ATM's typically beep, flash, and otherwise harangue you to take your card. Newer ATM's often use a swipe function to better match the user's goals. Sadly, I have yet to see a copier which places the original at the top of the copies.

Task mismatches of this sort, called the "post-completion error" in related research, is just one of the ways a task structure can fail to match the user's goal structure. Another kind of mismatch was recently observed in one of our client's sites. This e-commerce site offered a quantity form with each product listing and an add-to-cart button. This worked fine for pages with multiple products but caused numerous of errors and user fallout for pages with single products. In a multiple product scenario, the subgoal of selecting which products to buy is formed. With only one product, users followed their task model which said "to buy things on the web, find the items and put them in the shopping cart, and then checkout" and simply clicked the add-to-cart button. The site then generated an error and asked it's customer to specify a quantity. A quarter of the users left the site right then.

In examining your own websites, consider the processes users need to accomplish. Pay particular attention to the final steps and the wording associated with those steps to avoid post-completion scenarios. Always provide the equivalent of an express checkout lane and make advanced configuration an optional path. In any process, provide a roadmap of steps and a marker of current position. All of these techniques, and many more, come from a understanding of the user as a goal directed information processor with a limited capacity and temporal cost for attention.