Pros and Cons Human/Assistive Technology Interface

Elements of the Human/Technology Interface

Earlier this year, we learned that one of the most anticipated technologies ever to be offered to consumers would soon be available. It would revolutionize our lives, improve our connectivity with others, and manage complex information elegantly and error free. No, we're not talking about the personal health record. We're, of course, talking about the Apple iPhone. With much hoopla and fanfare, the iPhone was unveiled at Macworld in January, lifting Apple's stock price by more than 10% and creating a flurry of tell-all blog entries and bootlegged video footage of the announcement. The slim, elegant device offers a unique touch screen navigation system with robust rich media display, in addition to Bluetooth and Internet connectivity.

Perhaps the most striking innovation of the iPhone is its unique user interface, Multi-Touch. The patented technology is able to discriminate accidental taps from intentional touches and press-button taps from list-scrolling sweeps. In developing this technology, Apple designers were able to do away with physical buttons, keyboard and stylus -- allowing for a new level of interaction between humans and technology. Though it's still too early to see how the iPhone will perform in real-world situations, it's clear that Apple continues to push the frontiers of computer-human interaction design, allowing us to handle and process a growing array of information more efficiently. Certainly, we could benefit from some of those principles in electronic health record design.

 

Characteristics of Control Interfaces

It is very important to identify the characteristics desired of a good user interface. Because unless we are aware of these, it is very much difficult to design a good user interface. A few important characteristics of a good user interface are the following:

• Speed of learning. A good user interface should be easy to learn. Speed of learning is hampered by complex syntax and semantics of the command issue procedures. A good user interface should not require its users to memorize commands. Neither should the user be asked to remember information from one screen to another while performing various tasks using the interface. Besides, the following three issues are crucial to enhance the speed of learning:

Use of Metaphors and intuitive command names. Speed of learning an interface is greatly facilitated if these are based on some day-to-day real-life examples or some physical objects with which the users are familiar. The abstractions of real-life objects or concepts used in user interface design are called metaphors. If the user interface of a text editor uses concepts similar to the tools used by a writer for text editing such as cutting lines and paragraphs and pasting it at other places, users can immediately relate to it. Another popular metaphor is a shopping cart. Everyone knows how a shopping cart is used to make choices while purchasing items in a supermarket. If a user interface uses the shopping cart metaphor for designing the interaction style for a situation where similar types of choices have to be made, then the users can easily understand and learn to use the interface. Yet another example of a metaphor is the trashcan. To delete a file, the user may drag it to the trashcan. Also, learning is facilitated by intuitive command names.

Consistency. Once a user learns about a command, he should be able to use the similar commands in different circumstances for carrying out similar actions. This makes it easier to learn the interface

since the user can extend his knowledge about one part of the interface to the other parts. For example, in a word processor, "Control-b" is the short-cut key to embolden the selected text. The same short-cut should be used on the other parts of the interface, for example, to embolden text in graphic objects also - circle, rectangle, polygon, etc. Thus, the different commands supported by an interface should be consistent.

 

Component-based interface. Users can learn an interface faster if the interaction style of the interface is very similar to the interface of other applications with which the user is already familiar. This can be achieved if the interfaces of different applications are developed using some standard user interface components. This, in fact, is the theme of the component-based user interface. Examples of standard user interface components are: radio button, check box, text field, slider, progress bar, etc.

The speed of learning characteristic of a user interface can be determined by measuring the training time and practice that users require before they can effectively use the software.

 

• Speed of use. Speed of use of a user interface is determined by the time and user effort necessary to initiate and execute different commands. This characteristic of the interface is sometimes referred to as productivity support of the interface. It indicates how fast the users can perform their intended tasks. The time and user effort necessary to initiate and execute different commands should be minimal. This can be achieved through careful design of the interface. For example, an interface that requires users to type in lengthy commands or involves mouse movements to different areas of the screen that are wide apart for issuing commands can slow down the operating speed of users. The most frequently used commands should have the smallest length or be available at the top of the menu to minimize the mouse movements necessary to issue commands.

• Speed of recall. Once users learn how to use an interface, the speed with which they can recall the command issue procedure should be maximized. This characteristic is very important for intermittent users. Speed of recall is improved if the interface is based on some metaphors, symbolic command issue procedures, and intuitive command names.

• Error prevention. A good user interface should minimize the scope of committing errors while initiating different commands. The error rate of an interface can be easily determined by monitoring the errors committed by average users while using the interface. This monitoring can be automated by instrumenting the user interface code with monitoring code which can record the frequency and types of user error and later display the statistics of various kinds of errors committed by different users.

Moreover, errors can be prevented by asking the users to confirm any potentially destructive actions specified by them, for example, deleting a group of files.

Consistency of names, issue procedures, and behavior of similar commands and the simplicity of the command issue procedures minimize error possibilities. Also, the interface should prevent the user from entering wrong values.

• Attractiveness. A good user interface should be attractive to use. An attractive user interface catches user attention and fancy. In this respect, graphics-based user interfaces have a definite advantage over text-based interfaces.

• Consistency. The commands supported by a user interface should be consistent. The basic purpose of consistency is to allow users to generalize the knowledge about aspects of the interface from one part to another. Thus, consistency facilitates speed of learning, speed of recall, and also helps in reduction of error rate.

• Feedback. A good user interface must provide feedback to various user actions. Especially, if any user request takes more than few seconds to process, the user should be informed about the state of the processing of his request. In the absence of any response from the computer for a long time, a novice user might even start recovery/shutdown procedures in panic. If required, the user should be periodically informed about the progress made in processing his command.

 

Selecting Control Interfaces for the User

Selecting a UCI consists of adding controls and other items to the UCI in the UCI Design Interface. You can do this by the methods listed below. Once you a number of items in your UCI, you will probably want to arrange them to increase usability and appearance. Q-Sys provides a number of tools to do that.

• Properties - the Properties of a selected item are located in the right side pane of the Q-Sys Designer workspace, and contain the following items:
  • Position coordinates of a selected item allow you to place an item exactly where you want it to be. The left number controls horizontal placement of the left side of the selected item, the right number controls the vertical placement of the top edge of the selected item.
  • Control the Size of the selected item. The left number controls the width (horizontal), and the right number controls the height (vertical) size of the item.
  • Other items in the Properties include Fill color, Corner Radius, Stroke Color, Stroke Width, and Text Color, Size, Weight, and Horizontal Alignment.
• In the UCI Design Interface there are a number of tools you can use:
  • In the Tools drop-down menu there is Group / Ungroup (Ctrl+G) / (Ctrl+Shift-G), Align, Distribute, Pack, and Order.
  • Guidelines - When you open the UCI Design Interface, the working area is defined by a light blue background surrounded by gray area. If you place your cursor in the gray area above or to the left side of the working area, you will see a guideline displayed across or down through the workspace. The guideline moves with the cursor, and coordinates are displayed as you move the guideline.
    • Click the cursor where you want the guideline to remain. Continue adding guidelines as needed.
    • To move a guideline, move the cursor over the guideline in the gray area then click and hold when the cursor becomes a double arrow over the desired guideline. Drag the cursor to the place you want it. You can zoom in on the area if you need to in order to see the coordinates.
    • After setting your guide lines, you can use them to align items in the UCI.
  • Copy/cut and Past UCI pages.
    • To copy or cut a UCI page, select the UCI page under the UCI in the User Control Interfaces panel, then press Ctrl+C/Ctrl+X, or select Edit > Copy/Paste.
    • Select the destination UCI, and press Ctrl+V or select Edit > Paste. The page now displays in the destination UCI.
       
      Control Interfaces for Direct Selection

• Various Types of Keyboard (standard, ergonomic, tongue touch)
• Pointing Interfaces (mouse, trackball, head-controlled mouse, light pointer)
• Speech Recognition (speaker dependent and trained vs. speaker-independent, phonologist)
• Eye Control (eye blinks/stares, IR detection and recording, head- (dash-dot communication). Darci code uses an 8-way switch code (joystick positioning).

 Control Interfaces for Indirect Selection

• Auto-Scanning - selection set presented on display, sequentially scanned by cursor on device. When a particular element is presented, user generates a signal. Rate of scan is set by user.
• Step Scanning - switch is activated for each item, second switch or dwell used for acceptance signal.
• Inverse Scanning - hold to initiate scan, release to select.
• Directed Scanning - user selects direction of scan, the set is scanned sequentially by the device, then signal is generated by user.
• Coded Access - Morse code is common example.
  
  

Internet Use by Persons with Physical Disabilities

Technologically assistive devices are increasingly playing more important roles in the lives of persons with disabilities, with one of the more promising considerations being a combination of the functions of computer software and hardware. However, using a conventional keyboard for Internet access is prohibitive for persons whose hand coordination and dexterity are impaired by ailments such as amyotrophic lateral sclerosis, multiple sclerosis, muscular dystrophy, and other severe handicaps. To assist participants with physical disabilities in sharing the resources of the Internet, we designed and implemented an easy-to-operate wireless input interface using Morse code as the adaptive communication tool. Moreover, a adaptive Morse code recognition process is introduced. After two months' practice on this system, three participants with physical disabilities could conveniently gain access to the Internet.

 

Other Considerations in Control Interface Selection

As with the purchase of any computer based hardware add-on or software package, there are several performance and positioning issues to consider prior to purchase to ensure that the newly acquired items will function with the system they are augmenting.  This section highlights several of these general considerations.  Additional considerations that are specific to the type of accommodation being made will be addressed in the sections on visual impairment, hearing impairment, and mobility impairment that follow.

 

General Hardware Configuration Considerations:

• Do the hardware solutions require a board slot in the computer or a serial or parallel connection?  Is the proper connection available?
• If a board is used, does it present any compatibility problems with other boards in the PC?  Other EGA or VGA boards? LAN boards? Terminal emulation boards?  If an incompatibility exists, can the board interrupts or maps be changed?
• Is the speed of the PC and the board compatible?  Some devices require at least an 80286 based PC, while others will not function properly on that PC platform.

 General Software Compatibility Considerations:

• Will the software run with the existing monitor?  EGA, CGA, VGA compatibility?
• How much RAM is used by the software?  Is there enough RAM in the PC to run both the necessary application packages and the accommodation software at the same time?
• Can the software be loaded in extended memory?
• If a terminate-stay-resident accommodation software solution in used, does the LAN software leave it active, or does it override?
• Are there any memory management conflicts that need to be resolved?
• Will any terminal emulation software used allow the accommodation software to remain active?

Development of Motor Skills for Use of Control Interfaces

Assistive Technology that provides manipulative activities for improving fine motor skills, perceptual skills, sorting skills, hand eye coordination, and more. Children with physical disabilities find gross movements difficult and may also have difficulties with finer movements, or a combination of both. Many students with physical disabilities cannot write or type, others can only do so at a slow pace and the end result may still be illegible. To be considered a disability, the problem must cause a person to have motor coordination that is significantly below what would be expected for his or her age, and the problem must interfere with the activities of learning and daily living.