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“Successful screen design is founded on the developer’s deep understanding of both the user and the data.” – Bryce’s Law

Introduction:
There once was a hospital in the Midwest that sought to automate their patient admission forms. Hospital forms, as we all know, can be complicated and extensive (thanks to those pesky lawyers), and this particular hospital was no exception. This complexity made it challenging for the hospital to gather crucial data about patients, their physicians, and their insurance carriers. To simplify the data collection process, they decided to automate the forms. Unfortunately, the resulting screen designs were essentially replicas of the forms themselves. They were cluttered, confusing, and lacked proper editing checks. Frankly, they were no better than the forms they aimed to replace, resulting in inconsistent usage of the screens.

Designing a computer screen is not much different from designing a paper form. However, since most developers today have little experience in forms design, it may be necessary to revisit the fundamentals of good design. In order to create a successful screen design, we must consider the man/machine interface, also known as ergonomics. This means understanding the intended user, including their intelligence level and senses. Users with strong computer skills will have an easier time navigating complex screens compared to those less familiar with technology. We must also consider the limitations of the user’s senses, such as color blindness. Knowing our intended user is key.

For more information on ergonomics, check out No. 65 – “What Ever Happened to Ergonomics?” – March 6, 2006 http://www.phmainstreet.com/mba/ss060306.pdf

The objective of good screen design (and forms design) is to create something that is intuitive, minimizes confusion, and effectively collects data and presents information. While the discussion that follows can be applied to screens used in character-based operating systems, it primarily focuses on Graphical User Interfaces (GUI) used in today’s popular operating systems.

The GUI was first introduced with Xerox’s Star computer in the early 1980s. It quickly gained popularity due to its revolutionary ease of use. However, the lack of standards posed a challenge, as different GUI programs did not behave consistently. Fortunately, standards began to emerge in the late 1980s with IBM’s CUA standards (Common User Access), which provided a comprehensive set of design guidelines for GUI-based programs. The introduction of these standards meant that users familiar with one GUI program could easily adapt to using another, as they followed similar patterns. While different vendors may interpret the CUA standards differently, designing a GUI screen in accordance with accepted standards is still preferable to designing a screen without any standards.

Design Considerations:
Today, there are powerful tools available for quickly building screens. However, developers should always keep three fundamental design considerations in mind: Layout, Data Entry, and Support.

A. Layout:
The goal here is to create a clean and consistent screen. Too much detail can clutter the screen and overwhelm the user. When designing your screen, consider factors such as eye movement, eye strain, and the potential need for magnification. Here are some tips to consider:

Alignment: Ensure that the elements on the screen are symmetrically aligned. Disjointed alignment can alienate users. Leave comfortable spacing around the edges and between different sections of the screen. Keep in mind that GUI windows can be resized, so consider how the screen will appear in different sizes. Use borders to define sections, but be careful not to make them overwhelming or distracting. Zoning: Establish clear sections within the screen. This is helpful when different types of users will be accessing the same screen or if different sections serve distinct purposes. Borders, colors, and notebook tabs in GUI windows can be useful for distinguishing sections. Flow: Create an obvious flow that guides the user in the intended direction. Keep in mind that Western countries generally read from left to right and top down, while Eastern countries read top down and from left to right. Middle Eastern countries read from right to left and top down. Use the tab order of the keyboard to provide direction for the user. Ensure that the tab order follows a logical sequence and does not jump around randomly. Type Fonts: Stick to common fonts that users are familiar with. Fancy fonts may look impressive, but they may not be supported on all computers where the screen will be accessed. Preferred fonts include Arial, Courier, Sans Serif, and Times Roman. Establish a standard font point size; 10 is generally readable for the average person, but consider whether your end-users will be average. Develop a standard scheme for upper-case and lower-case lettering and type styles, such as bold or italic. These subtle details can naturally attract the user’s eye. Colors: Colors can be helpful for highlighting sections, accenting required field entries, or for overall appearance. However, be mindful that colors can also be distracting if overused. Ensure that color contrasts make the screen easily readable. Consider the needs of colorblind users. Headings: Place screen headings in a standard position for easy identification. Include a formal name and, if applicable, a screen number that is clearly visible to the user. Keyboard/mouse relationship: Ensure that, even without a functional mouse, the user can still navigate the screen using simple keyboard commands. CUA standards are particularly helpful in this regard.

B. Data Entry:
Proper data entry is just as important as the physical layout of the screen. Unfortunately, many designers take a superficial approach to data collection, resulting in a significant amount of time spent cleaning up data in the database. However, with a little effort in screen design, considerable time can be saved. The objective is to create a screen that collects clean data, eliminating the need to correct “dirty” data later on. Before starting screen design, developers should have a deep understanding of the data specifications. This information can be obtained from a reliable data dictionary/repository or the physical database design. Specifically, developers need to know:

Length: The maximum number of characters allowed for a data element.
Class: The type of characters allowed, such as alphabetic, numeric, alphanumeric, signed numeric, etc.
Justification: The alignment of data within a field when the number of characters is less than the field’s length, such as left, right, or around the decimal point.
Fill Character: The character used to complete a field when the data item is shorter than the maximum length, such as blank, zero, X, etc.
Void Character: The character used when a data item’s value is unknown or nonexistent, such as blank, zero, X, etc.
Unit of Measure: The representation of numeric data, such as area, volume, weight, length, time, energy rate, money, etc.
Precision: The number of significant digits in a number for numeric data.
Scale: The placement of the decimal point for numeric data.
Validation Rules: The specific values that a data element can assume, including default values, editing rules, etc.

In summary,…
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Ihab Salloum