Heuristic Analysis of Improvement 2
One of the main arguments against using quantitative analytical methods when assessing usability is that it is completely unrealistic to account for every detail that can effect the human cognitive process. This makes it impossible (for now, at least) to convincingly state that any type of metric can be used to accurately measure the speed of thought. This is the main reason why, even though significant changes were made in the second new version of the add-rule task, very little change is shown in the projected completion time when compared to the first.
However, in Improvement 2, the task flow and the informational layout are improved, there are now access to advanced rule creation and management features, and task widgets are now made more visible. Clearly, all of these features would improve the usability at least a little bit for any user. This shows that the usability improvements that were made simply cannot be quantifiably measured, at least not using simple GOMS.
Some of the empirically undetectable improvements made in Improvement 2 as they relate to the 8 golden Rules are:
- Consistency - This has been addressed in multiple ways in Improvement 2: first - similar to Improvement 1, in the second version many steps were combined into a single screen, second - the graphic layout of the new-rule input box is organized better. Having the rule criteria form elements less jammed together allows for easier scanning and ensures that the entire sequence of actions is noticed and the realization of rule creation.
Impact assessment: The improved uniformity of information display and interaction definitely improves the task-action interface. It could be that either GOMS did not pick up on certain inefficiencies in Improvement 1 or that it is not picking up on improvements in Improvement 2 but, whichever one it is, the second task version is definitely a useful improvement.
- Universal usability - The simpler, more even layout (along with the continued reduction in the number of steps) would be useful to both novice and advanced users, thus negating usability differences across user skill levels. Also accommodating user differences, added functionalities, such as the multiple rule-condition text boxes and advanced rule management access (the button marked, 'Advanced,' at the bottom), will prevent user frustration or confusion.
Since this interface is more accommodating to different user types, especially leveling the playing field for both advanced and novice users, improvements in task completion are probable.
- Informative feedback - Same improvements that apply to Improvement 1 also apply to Improvement 2 if the verification screen is included.
Impact assessment: Both of these improvements give the user the confidence to know that she is doing the right thing and that the outcome will be as desired, which can decrease hesitation, thus improving efficiency and experience.
- Design dialogs to yield closure - The only change is that the step numbers are now set out more from the body text, which emphasizes the different steps to the process and the order in which they should occur.
Impact assessment: This minor detail can take undetectable burden off of the user's thought process, improving task flow and user experience.
- Error Prevention -
Computer uses some logic to automatically complete some parts of rule creation and error messages will be returned if the rule has not been completed.
Impact assessment: These actions save time and reduce in the number of things that the user needs to attend to.
- Reversal of errors - A message verification rule was not originally included in this version because it was thought that, because of the improved clarity in information presentation, it would not be necessary. It would probably still be useful for novice users who are not accustomed to the semantics of computer logic. However, there may be more negative impact on user experience if it is included than if it is not.
The differing needs of expert and beginner users often lead to conflicting design decisions. The most frequently encountered example of this is that beginners need more instruction and experts want unhindered interaction. If a verification window that displayed the created rule as a natural language sentence were to pop up at the end of rule creation it would help users to understand what they had done and what effect it would have it could be very helpful to beginners. However, to more advanced users, a pop up window would surely be seen as an impediment. A possible decision making point is that all beginners will eventually become advanced, quite possibly after the first time they have created a rule and so there would almost always be more experts than beginners. Therefore, it seems like the best decision would be to not include this verification step.
Before the final decision is made, though, one must consider all purposes that the verification window serves. The first thing it does is improve understanding and the second is to provide a mechanism for reversing errors before any they are committed. This second reason outweighs the first according to many schools of thought for good reason.
Impact assessment: As described, there are positive and negative aspects to whether the verification window is provided or not. However, its inclusion would probably prevent more errors from being committed in the long run and thus provide more of a positive impact even though it would be very nearly imperceptible.
- Locus of control - This is similar to Improvement 1, especially by reducing the number of windows that open during rule creation. Improvement 2 also adds a "handle bar" that makes it more obvious that the window can be dragged so as not to obscure lower windows.
Impact assessment: Improvements are the same here as in Improvement 1 except that familiarity with the lexicon of widget level affordances in Windows might relieve some concerns and make the task more intuitive.
- Reliance on Memory - These improvements are the same as in Improvement 1.
One additional benefit to using Improvement 2 is that the number of rule conditions and actions has been greatly reduced to only the most commonly used. The reason for this is that, as this is meant to be a quick-rule creator and is more easily accessible (both in how to get to the task and in terms of understandability), the people who would be using it would probably be less interested in the number of options given and more so in clarity and simplicity.
One possible faults is that the label, "Advanced", on the button at the bottom of the window is not very descriptive. Perhaps a label more like, "Manage Rules" or "Advanced Rules," would be more useful.