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Physical interaction

7 September, 2015 - 12:26

Physically, the interaction takes place via some device. In the generic case assumed in this chapter , this will be a personal computer hooked up to a network (often the Internet, but sometimes to the organization’s internal network). The devices that are available are then a keyboard with a mouse, a screen with a given resolution, and a printer, most often based on inkjet technology. When the user population is the general public, you must be prepared to accommodate a variety of technical solutions: some users may have a lower screen resolution, some may have slow printers or no printers at all. The operating system and the browser—the software that enables the PC to communicate with the Internet—may also vary from user to user. You must therefore be careful to use the “lowest common denominator,” the minimum capability likely to be available to all users.

Alternative means of interaction are available. Historically, users communicated with computers via forms that were filled in and transcribed to paper tape or cards in the form of patterns of holes. Early on, machine-readable data formats were developed such as optical character recognition (OCR) and magnetic ink character recognition (MICR). These had severe technical constraints but are still widely used in specialized applications such as check processing and invoice payments (where the account number and invoice amount are printed in OCR font on a slip that the customer detaches from the invoice and sends in by mail with the payment). The retail industry developed an industry-wide standard Universal Product Code (UPC) in the 1970s, embodied in bar codes on grocery packages, in books and on most other products. Similar in principle (but technologically quite different) are the magnetic stripes on the back of credit cards(often extended to membership cards that enable checking in and out as well as dispensing membership services). These forms of interaction require some specialized equipment, ranging from a hand-held scanning wand to an automated teller machine (ATM).

More recent developments include using touch-tone telephones for data entry. Automated response systems take phone callers through a series of menus to direct their calls either to a person with whom they can interact or to voice messages (either generic information useful to any customer or customer-specific messages, such as a credit card balance, generated on the fly). It is also possible for the caller to be asked to enter a series of digits—a customer number, a password or Personal Identification Number—or even alphanumeric text. Internet applications are emerging that are specifically designed to interact with mobile phones that use video and audio as well.

Another recent development is the use of Radio Frequency Identification (RFID), miniature transponders located in products, library books, electronic toll collection devices in cars and trucks, and cattle, to mention but a few uses.

For some very large systems, the development of a new input/output device may even be justified, as with the hand- held, wireless package tracking devices used by Federal Express.

In all cases, you must address two issues. First, how can the users get access to the interaction device? Are they likely to have a PC or a cell phone? Are they likely to adapt to using them as interfaces? (Cell phone texting may not be optimal for a system catering to retirees, nor may PCs with landlines connected to the internet be the most appropriate solution in remote, non-electrified regions.) Alternatively, if the users are the organization’s own workforce, what is the cost of equipping them? Second, whenever a user interacts directly with an information system, there is always room for doubts about the identity of that user, so you must decide what level of user authentication is necessary and how you can achieve it. There exists technology that is solely devoted to this authentication, such as fingerprint and retina scanner; other, frequently used solutions rely on password or PINs.