Jane It is easy to want to focus on the first part of this “equation” because buttons, lists, browsers, and widgets in general are familiar to us. We can talk more concretely about those things we can see rather than about how someone might perceive information or react to a prompt. However, the widgets that appear in an interface are a collection of touchpoints with the user. These touchpoints are the results of a great deal of anlaysis of human behavior, work habits, environmental anlaysis, and user feedback. UI design is not graphic design. The graphic element of UI design is only the presentation level of all user interaction with the system. You also have a very good article in your resources section called “ Usability is Not Graphic Design .” This article discusses the common misconception that what a usability engineer does is makes things pretty.
Jane If you remember only four things from this class, I hope it is these four principles. If you can remember them, they will be your guide to dealing with every UI decision or problem that arises.
Jane Let’s talk about human limits. Not in the sense that human beings are dumb or that they can’t do anything right. We’re talking here about basic human-computer interaction points from a human point of view. There is a very interesting book called Things that Make us Smart by Don Norman. In that book, Norman points out that it’s OK to have human strengths and weaknesses because computers also have strengths and weaknesses. Usability problems arise when there is a situation that reveals the weaknesses of the user or the weaknesses of the computer. Another possibility is some mismatch of how the two work together. Example: sorting a list of alphanumeric strings for 8 hours visual inspection
Jane Lot’s of eye movement causes visual fatigue--the more people have to search a screen for information or scrutinize a screen to figure out what to do, the more taxing it is on their eyes. Over the course of a day, people who have to struggle with visual clutter or mayhem will become very visually fatigued. Color and highlighting indicate meaning. People give meaning to color. This has strong implications for cultural or international designs--different colors mean different things in different cultures. 9% of men and 2% of women have some form of color blindness or color confusion. Don’t rely on color alone to provide cues. Consistent format goes back to the first point. If every screen presents a new layout or inconsistent placement of buttons, the effort to use the application increases. People scan--This has particular significance in dialog boxes. There needs to be a visual indicator in danger situations so that people slow down and read at least some of the info in the dialog. Scan - conclusion “it’s not there.”
Erin Attention Spans: Between individuals and Across Individuals Our software is just one piece of their tasks to get their job done. Fatigue: Leads to increased probability of errors Senses: Shop Floor - noisy environment Key Combinations - where they keys are Keyboard/mouse on Web: Tab and Enter are supported on Web, and sometimes Esc; otherwise you can’t count on keyboard shortcuts. More mouse clicks needed to do the same thing on the web as in a GUI. After last bullet: Quote from Thornton May presentation to AIIM on 9/28/98: “2/3 of all the people who have ever lived to age 65 are alive today” People are staying in the workforce longer - new challenges for design.
Erin--slide & short term memory activity Limit a person’s memory load. Note: example of limiting memory load is to show a file name rather than expecting the user to remember the file name as they move between windows. Provide Context! Example of breaking down decision-making into chunks: group boxes around a group of widgets that are related. Sorting options so that they can look at the data in different ways to make different decisions. Exaggerated sense of time when in a hurry - e.g., stoplights. Need for Visual Indicators - feedback. (OMF example of opening worklist 5 times) ACTIVITY: short term memory activity goes here. Should take no more than 10 minutes. See notes on next page.
Jane People expect the interface to communicate WITH them, and believe that computers will follow the same rules of communication that exist for human to human interaction. They expect the interface to be flexible and give them feedback. Emotions: Users may have had a negative or positive experience with a previous system and they tend to generalize those emotions to your new system. People “like” a system or “trust” the system. People want computers to be predictable. As they work, they want to be able to predict the computer will respond, or even to eliminate thinking about the possibility of any unpredictable response. Context provides specific meaning and interpretation options. Out-of-context information takes longer to understand and is often misunderstood. Context on a software screen is developed through title bar names, labels, and grouping of information. Mental models are picture of how something should work or act. People develop mental models based on their own experiences, and these models may not always be correct. (Example--lights and windshield wipers in a car--where are they located?) (Example--Frau and the defroster in the new car) Book “The Media Equation” by Reeves and Nass, 1996.
Jane To summarize what we’ve been talking about, this is a list of the basics. These are design constraints that must always be at the forefront of your mind as you design an interface or as you evaluate an interface or as you write about an interface.
As we discuss these stages, we will point out 3 things at each stage: 1. What the “market at large” is doing during the stage. 2. What development teams generally tend to do during each stage, based on market behavior. 3. Usability issues and user perceptions during each stage. (Instructor - would a blank table with the 3 headings be easier for people here?)
Jared Spool refers to the first stage of a product in the market as Raw Iron. After 1st bullet: NOVELTY (Show four bullet points) (After last bullet point): As users get more and more sophisticated, and as products get more “plentiful” this stage gets shorter and shorter. Technology has really changed the length of this stage. There are some factors that are critical to this stage and also at all of the future stages we will discuss--we are not going to focus these in detail. However, a company’s market position is a key factor here and in all of the future stages. That means that based on whether a company is a market leader, a contender, a niche player, or a startup, the company’s exact behavior during a stage may be influenced by their market position. That is a whole other class, so we’re not going to go there--but keep that thought in the back of your mind as we get into discussions about the stages and what they mean.
The transparency stage is somewhat difficult to explain without giving examples of products that have become transparent. One example of a product that is on its way to becoming transparent (and some would say already is transparent) is the PC. Price has become a differentiator. There are still a few features that are valued as must-haves, but most PC’s are alike in feature and function.
These section headings (e.g. ANALYSIS, DESIGN, TESTING) are not methodology phase names. They are simply labels to group the type of duties we perform. The ANALYSIS duties are started during the Concept phase and finished during the System phase Conceptual Design is started during the Concept phase and finished during the System phase Collaborative Design and Image Creation occur during the System and Implementation phases The TESTING duties can be performed during any phase
Usability Engineering - 1 Sameer Chavan
Designing for Humans What is a User Interface? “ The place at which independent systems meet and act on or communicate with each other”
Software User Interface
“ Narrowly defined, the software interface comprises the input and output devices and the software that services them;
Broadly defined, the interface includes everything that shapes user’s experiences with computers, including documentation, training and human support”
Various vendors provide nearly identical products.
Price becomes a key differentiator.
- Usability means that the product has essentially become invisible to users. - There is no advantage in further modifying the product for the targeted market. - Companies focus on lowering production costs
Market Maturity Model Technology Focus User Focus Market Maturity Over Time
Users don‘t like Unexpectations Access denied O.k., and now you‘ll do exactly what I‘m telling you !
To succeed in market, Superior Technology is not just enough, we must supply a satisfying user experience
Technology Maturity Model Donald Norman ….”Invisible Computers”
Usability & Software Development life cycle Understand the User & .. Do user Task Analysis Define User Requirements Develop Interactions Concept Develop Prototypes Test Test Software Development Test Release Test Requirements Capture Design Development Usability Evaluation / Usability Testing
What suits one customer might not suit the next
Sensers, who like to see interfaces that are concrete, down-to-earth, and related to the physical world, are more likely to forget how to access the pop-up menu on the right mouse button, lacking the visual clue.