In Chapters “Designing Effective Output“, “Designing Effective Input“, and “Designing Databases” you learned the basis for sound design of screens, forms, Web sites, and databases. This included the special use of fonts, color, and layout design to communicate to users and to help them do the right thing with the input and output they encountered. To examine the underlying reasons for much of the design you learned, it is useful to look at human sensory capabilities and limitations that will inform our design. In keeping with the HCI philosophy, an analyst should be able to compensate, overcome, or replace human senses to a varying extent.
As you become a systems analyst, you are becoming accustomed to designing screens and reports for sighted people. The use of color, fonts, graphics, software, and PowerPoint presentations for displays and printed reports as input and output were detailed in Chapters “Designing Effective Output” and “Designing Effective Input“. However, from an HCI perspective, you will also want to think in terms of limitations on human vision. Factors such as length of the distance from display to the person performing a task; the angle of the display in relation to the person viewing it; the size and uniformity of the characters; the brightness, contrast, balance, and glare of the screen; and whether a display is blinking or stable can all be designed to standards established through ISO and other national and international groups.
Humans also have limits to the amount of stress their senses can withstand. Noisy laser printers, phone conversations, and shredders can lead to overload on human hearing. Office workers can wear noise-canceling headphones or get a personal music player like an iPod, but these solutions may have the effect of isolating a person from the organizational setting and may even diminish their capability to perform the task at hand. As an analyst you will need to consider noise when you design office systems.
When using an HCI perspective to evaluate the usefulness of keyboards and other input devices, we can rate the human–computer fit as well as the dimensions examining the human–computer–task fit. Keyboards have been ergonomically designed to provide the correct feedback for the person doing data entry. Users know by the firmness of the key under their finger that the keystroke has been entered. Although keyboards can be silenced, they are often designed with a click of feedback that is emitted when a key is hit. Keyboards also include slightly raised bumps on what are called home keys, often the f and the j keys, which orients users to where their fingers are positioned on the keyboard, enabling them to look at the screen or type from a printed page on their desk without continually glancing at the keyboard.
Although the popular QWERTY keyboard that we most often use with computers today was originally designed to slow down typists so that mechanical keys of the day would not become entangled, this layout has proved to be quite an efficient way to enter data. In fact, since users do so well with this familiar interface, it is difficult to conduct experiments comparing the efficiency of QWERTY keyboards with other innovative keyboards.
Designing for data entry using numeric keypads as the human entry device also provides a decision point for designers. Notice that numbers on your mobile phone are ordered differently than numbers on a numeric keypad or calculator. Your phone may be arranged with the numbers 1, 2, and 3 on the top row. When you look at a calculator layout or a numeric keypad on your keyboard, you will see 7, 8, and 9 on the top row instead. Research now points to the superiority of the calculator layout when the user is doing a lot of data entry. However, the phone digit layout is supposed to be better for locating a number. As a designer, you are constantly examining the fit between the human, the computer, and the tasks set by the organization.
