National Academies Press: OpenBook

Technology for Adaptive Aging (2004)

Chapter: Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society

« Previous: 4 Methodological Issues in the Assessment of Technology Use for Older Adults
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

Part III
Domain-Specific Papers

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

This page intentionally left blank.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

5
Addressing the Communication Needs of an Aging Society

Susan Kemper and Jose C. Lacal

COMMUNICATION NEEDS OF OLDER PEOPLE

The possibilities for using technology to meet the communication needs of an aging society are as broad as the communication needs of individual older adults. The ability to communicate is essential if older adults are to solicit assistance with daily living activities; fulfill lifelong learning goals; gain access to health and legal information from print, broadcast, or electronic media; or enjoy intergenerational contacts with family members. Older adults need to communicate with their families, friends, neighbors, and with their lawyers and physicians through face-to-face interaction and over the Internet.

Common barriers to communication include the declining sensory, cognitive, and physical abilities of older adults. Recent technological advances have led to the development of a dazzling variety of new technologies for assistive and augmentative communication for individuals with severe disabilities: Communication systems that recognize speech and translate it into American Sign Language displays in real time; “direct-select” speech synthesis systems with built-in 100,000 word vocabularies and concept- and grammar-based word prediction to speed message construction; communication systems that respond to a variety of inputs including “eye typing;” low-vision magnifiers with electronic page turners; portable optical character recognition programs that translate scanned or electronic text into speech or into Braille; talking picture books; telephones based on bone conduction; and laryngectomy speech amplifiers. These

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

new technologies have dissolved communication barriers for children and adults with disabling conditions.

But search for communication devices that serve older adults who suffer only from normal aging with some hearing loss, some forgetfulness, some word retrieval problems, some slowing of cognitive function, and the list of communication aids suddenly shrinks. There are hearing aids, to be sure, and reading magnifiers to compensate for presbycusis and presbyopia; there are telephones with volume control and large buttons; but there is not much more currently available than these types of devices to amplify and magnify.

Charness (2001) suggested that “consumers of communication technologies are moving into something of a golden age” (p. 22). This golden age is to result from the rapid expansion of affordable, usable communication technologies such as videophones and web-based conferencing. However, this “golden age” of communication is likely to be tarnished unless these technologies are adapted to the needs of older adults who are likely, based on demographics alone, to constitute a significant proportion of their future users. One answer has been the proliferation of guidelines and standards for technology developers. Consider those of two recently issued white papers.

In 1999, the World Institute on Disability issued a bibliography on the use of telecommunications by people with cognitive disabilities. The report included a set of general design principles to overcome barriers to the use of telecommunication devices. Four “universal design” strategies were espoused:

  1. Redundant, user-controlled modality, e.g., using diagrams as well as text descriptions, providing auditory as well as written information.

  2. Streamlined, user-controlled amount and rate of information; user control of size and contrast of displays; user control of pitch, volume, rate, repetition of auditory information; reliance on recognition rather than recall for functionality.

  3. Procedural support to reduce memory load, to counter distractibility, to support planning and sequencing.

  4. Content organization: structure text for easy scanning, use hypertext anchors, support example and similarity-based search.

Many of these same recommendations were echoed by the 2002 National Institute on Aging (NIA) report Older Adults and Information Technology (Morrell, Dailey, Feldman, Mayhorn, and Echt, 2002) as a set of guidelines for web-site design:

  1. Designing readable text, recommendations for typeface, type size, the use of color and backgrounds.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
  1. Increasing memory and comprehension of web-site content, using clear writing with illustrations, animation, and other text alternatives.

  2. Increasing ease of navigation through consistent layouts, menus, site maps, and hyperlinks.

Both sets of guidelines are notable for their attempt to link specific recommendations to known barriers to communication with older adults, based on available research. It is not surprising that there is considerable overlap in the two sets of guidelines, as the World Institute on Disability considers aging to be a disabling “circumstance that correlates with cognitive impairments” (1999, p. 33). Nor is it surprising that these guidelines focus on overcoming issues of bad design with changes that would benefit all users, not just older or disabled users. What is surprising is that these guidelines focus primarily on design features, whether of web sites, voice mail systems, or cellular phones. All of these communication devices would indeed benefit from better design to enhance usability, and implementation of these design guidelines would undoubtedly benefit older users; however, they are insufficient. They will not address fundamental age-related barriers to communication.

Aging results in a number of sensory and cognitive changes that impose limits on communication; these limitations reach their most extreme when it comes to communicating with older adults with dementia. Note the overlap between these design guidelines for telecommunication devices and these recommendations for communicating with older adults with dementia (Bollinger and Hardiman, 1989) in Table 5-1.

Repetition, augmentation, amplification, and simplification are the recommended solutions to a variety of communication problems. The recommendations of Bollinger and Hardiman (1989) constitute a set of design guidelines for interpersonal communication. Yet these “guidelines” seem to be the very basis for the complaints of Anna Mae Halgrim Seaver in her posthumously published essay in Newsweek (Seaver, 1994, p. 11-12):

Why do you think the staff insists on talking baby talk when speaking to me? I understand English. I have a degree in music and am a certified teacher. Now I hear a lot of words that end in “y.” Is this how my kids felt? My hearing aid works fine. There is little need for anyone to position their face directly in front of me and raise their voice with those “y” words. Sometimes it takes longer for a meaning to sink in; sometimes my mind wanders when I am bored. But there′s no need to shout.

Most guidelines for communicating with older adults stress amplifying and augmenting speech to compensate for hearing loss. Hearing loss is a major threat to the social integration and psychosocial well-being of older adults (Tesch-Römer, 1997; Wahl and Tesch-Römer, 2001). Yet hearing aids, even if used, do not remediate these problems, although hear-

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

TABLE 5-1 Processes Involved in Communication Requiring Message Modification for Optimal Communication with Demented Patients

Problem

Recommended Solution

Sensory loss

Amplify: to increase the strength of the stimuli by making louder, isolating, marking

Augment: to add to by sending input through additional channels such as using spoken and printed words, gesture(s), and spoken words, touch and spoken word(s), and so on

Attention deficit

Amplify (see above)

Structure: to make a task, activity, event, or physical surrounding organized, consistent, and predictable, decreasing need for cognitive analysis

Augment (see above)

Perceptual changes

 

Exaggerate: to overemphasize by enlarging all segments of a message such as facial expression, intonation, loudness

Label: to name or describe objects and events as they occur in the environment of a person with dementia

Reduced speed

 

Repeat: to present again in exactly the same manner and form

Reduce rate: to slow the rate of presentation by increasing the interval between words and phrases; allowing more time for message from patient

Registration disorder

Repeat (see above)

Reiterate: to present a previous message with the same content but with different form or structure

Amplify (see above)

Memory reduction

Augment (see above)

Repeat (see above)

Decrease need: to assume an ability is not available thus providing a reminder, or performing the function for the person

Orientation disorder

Simplify: to reduce message to the basic form by shortening or deleting all nonessential words

Repeat (see above)

Reiterate (see above)

Augment (see above)

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

Reasoning disorder

Simplify (see above)

Eliminate need: if the task or message cannot be deleted from patient task, perform it for the patient

Language

Reiterate (see above)

Simplify (see above)

Amplify (see above)

Augment (see above)

Speech deterioration

Reduce time pressure (see above)

Augment (see above)

Assist: to prompt the patient by proving cues or asking questions that will aid in achieving a response

SOURCE: Adapted from Bollinger and Hardiman (1989).

ing-aid use is associated with a reduction in self-perceived hearing handicap (Tesch-Römer, 1997). It is not surprising that audiologists (Cutler and Butterfield, 1991; Levow, 2002; Uchanski, Choi, Braida, Reed, and Durlach, 1996) and hearing-aid manufacturers (Oticon, 2003) have therefore attempted to promote the use of “clear speech” for individuals who are hearing impaired. “Clear speech” recommendations typically parallel those of Bollinger and Hardiman (1989): speak slowly, speak loudly, insert pauses between phrases and sentences, stress key words, pronounce each word precisely, reduce background noise.

Thus, even in the case of hearing loss, the technological remedy offered by hearing aids must be supplemented by recommendations to speak clearly. Age-related hearing loss involves more than just presbycusis. So too, the reading problems of older adults—on or off the communication highway—will not be remediated by technological guidelines that address only visibility, because older adults′ reading problems result from more than just poor vision. Technological advances must move beyond considerations of visibility and amplification to address fundamental barriers to communication with older adults.

Three such barriers to communication with older adults are considered here: overaccommodations to aging, the prevalence of word retrieval problems, and the challenges raised by dual-task and multitasking environments. Each reflects a common source of complaints from older adults. Each has generated a considerable body of basic research. And each provides a potential access point for the application of technologies designed to enhance communication with older adults.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

THREE BARRIERS TO COMMUNICATION

Overaccommodations to Aging

Ryan, Giles, Bartolucci, and Henwood (1986) identified two patterns that contribute to older adults′ communication problems—underaccommodations and overaccommodations. Underaccommodations occur when the speaker or writer fails to consider how aging affects speaking and listening; overaccommodations occur when the speaker or writer is overreliant on negative stereotypes of aging. Underaccommodations put older adults at risk for social isolation and neglect because they lead to comprehension failure and hence to the possibility of misunderstanding, deception, and exploitation. The guidelines and design standards reviewed above address underaccommodations to the sensory and cognitive limitations of older adults. But it is easy for these remedies to tilt too far in the other direction, giving rise to overaccommodations to aging. Overaccommodations also put older adults at risk because overaccommodations are often perceived by older adults as insulting and patronizing and so may disenfranchise older adults from full participation in a conversational interaction. Ryan et al. (1986) suggested that overaccommodations to aging may trigger negative self-assessments by older adults of their own communicative competence and thus contribute to a downward spiral of sociocognitive limitations.

Overaccommodations to aging are often marked by the use of a special speech register termed “secondary baby talk” or “elderspeak” in interactions between young adults and older adults (Kemper, Jackson, Cheung, and Anagnopoulos, 1994). Elderspeak is marked by a slow rate of speaking, simplified syntax, vocabulary restrictions, and exaggerated prosody. It resembles an extreme form of “clear speech” but also the sort of speech adults use with infants and small children. It occurs in hospitals and nursing homes but also in lawyers′ offices, banks, senior centers, and grocery stores.

Research on elderspeak (Kemper and Harden, 1999) suggests that the short sentences and exaggerated prosody of elderspeak confer no positive benefit to older adults in terms of their performance on communication tasks. Using high pitch, a slow rate of speaking, and stressing important words may actually impair communication with older adults because this exaggerated prosody distorts vowels and other speech elements. Chopping up ideas into short phrases and simple ideas may eliminate causal and temporal connections essential for coherence and continuity. The exaggerated prosody and short choppy sentences of elderspeak also mimic baby talk. To be addressed in baby talk conveys the impression to older adults that they are cognitively impaired and childlike, reinforcing negative stereotypes.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

This line of research has also shown that older adults benefit from redundancy and repetition, particularly of complex messages. Even when complex syntax is used, older adults are able to follow directions if they can interrupt to request repetition and clarification. Thus, some aspects of elderspeak may be beneficial to older adults if they can be divorced from those that are hurtful to older adults′ self-esteem and those that simply are not helpful.

Implications for Technology

Although the core problem of the widespread use of elderspeak cannot be addressed by technology, technology can perhaps help with many of its manifestations. For example, the use of elderspeak over telephones and other electronic devices compounds many problems older listeners experience with these devices. Building in easy-to-use options for modulating pitch and amplitude might enable older adults to compensate for the high pitch that is characteristic of elderspeak. On-demand buffering of speech segments coupled with rate-adjustable playback might enable older adults to compensate for the slow rate of elderspeak (or too-fast rates of time-compressed speech typical of voice response systems and news broadcasts) so that an individual can adjust the rate of information transmission to their own processing rate. Buffering might also allow older adults to easily back up and replay critical segments, as repetition may be the necessary key to accurate comprehension. Speech-to-text capabilities might enable older adults to capture and record complex messages, instructions, or directions for later analysis.

Word Retrieval

Word retrieval problems are among the most common barriers to communication for older adults. Indeed, older adults cite problems remembering proper names as the most frequent effect of aging (Cohen and Faulkner, 1986; Sunderland, Watts, Baddeley, and Harris, 1986). They are the brunt of jokes about “senior moments” and the target of advertisements promising relief from the vexations of aging through herbal remedies and dietary supplements. Word retrieval failures disrupt conversations, impede orders and requests for services, and, for many older adults, raise the specter of dementia due to their alarming frequency and persistence. As one of the participants in Burke and Laver′s (1990) study commented, “If you want to study something really useful, find out why I cannot remember the name of my friend of 20 years when I go to introduce her” (p. 281).

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

Diary studies and experimental investigations have documented that older adults experience word retrieval failures more often than young adults. Proper name failures predominate in older adults′ diaries (Burke, MacKay, Worthley, and Wade, 1991), especially for names used infrequently and less recently. Burke and her colleagues have offered an explanation of word retrieval failures that also points to a role for technological intervention. The transmission deficit hypothesis holds that aging affects the strength of mental connections linking an idea to the pronunciation of a specific word—or in more formal terms, a network linking conceptual representations to phonological specifications. If one or more links between the idea and pronunciation is broken, a speaker will be able to retrieve the idea but be unable to translate that idea into an actual spoken word. The transmission deficit hypothesis model pinpoints the locus of the broken connection as between idea and word pronunciation, because speakers will often have partial phonological information about the target word as well as detailed information about the target idea. Older adults are more vulnerable to word retrieval failures because all network connections weaken with age; words are more vulnerable than ideas because words must be precisely articulated from a unique sequence of phonological features (pronouncing “cat” partially correctly might get you a “hat” instead) whereas ideas are redundantly specified by many converging associations and linkages (instead of thinking of a cat you might think of a lion or a tiger or Garfield). In a clever experiment, James and Burke (2000) (see also White and Abrams, 2002) asked young and older adults general-knowledge questions designed to promote word retrieval failures. The questions were embedded in a list of words. Sometimes these words shared phonological features with the target, sometimes they were unrelated to the target word. James and Burke report that fewer retrieval failures occurred when the target was preceded by phonologically related words than when it was not. For example, participants were more likely to correctly answer the question “What word means to formally renounce a throne?” [abdicate] when they had just read “abstract” than when they had read “reread.” White and Abrams (2002) report that words sharing the first syllable with the target, e.g., “abacus,” “abrogate,” are most effective at reducing word retrieval failures, whereas other words sharing other phonological features with the target, such as “indigent,” “handicap,” “educate,” and “duplicate” are ineffective.

Implications for Technology

One implication for technology developers is straightforward: Minimize opportunities for word retrieval failures by providing drop-down menus, lists of exemplars, and other options that are structured conceptu-

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

ally. Do not require someone to scroll through a list of names or retrieve a specific name, but provide conceptually organized options, e.g., relatives, friends, and business associates, and make creating that organization structure easy and transparent. A second implication is also clear: Accept partial phonological (or orthographic) information, especially word-initial fragments, in designing search engines, questionnaires, and other response formats. A third implication is less clear: Keep crucial phonological connections activated to avoid word retrieval problems. Based on the research of James and Burke (2000) and White and Abrams (2002), stimulating phonological connections maintaining linkages between ideas and words is the key to reducing word retrieval problems. Technology can potentially help with this—for example, by providing older adults with “talking memory books” that display visual, orthographic, and phonological information. Imagine preparing for a family reunion by scrolling through a family diary that displays photographs and biographic details while pronouncing the relative′s name. Or creating a high school reunion directory by pairing digital photographs with a digital audio record of the classmate′s name. Or ordering prescription medication by consulting a virtual pharmacist who displays the container and pill while articulating the brand name and generic name along with other medical information. Or “talking” name tags, perhaps linked to small optical scanners and miniaturized speakers embedded in eyeglasses. By activating phonological features, especially those used infrequently, such devices could spare older adults the communication disruptions triggered by word retrieval failures.

Dual and Multi-Tasking

Unlike computers, humans are poorly designed for dual and multitasking, and older adults are particularly prone to task disruptions when they are required to perform two or more tasks simultaneously (Sit and Fisk, 1999). This is nowhere more apparent than in common communication situations such as holding a conversation at a congregate meal site against a background of conversations at other tables or at home against a background of television or radio broadcasts. Sounds like “elevator music”; electronic hums and buzzes from computers and ventilation systems; and beeps and alarms from cell phones, pagers, and “smart” appliances all contribute to older adults′ communication breakdowns. Older adults′ difficulties understanding speech in noise are well documented (Schneider and Pichora-Fuller, 2000) and are often attributed to presbycusis as well as to age-related neuronal loss affecting noise dampening, frequency, and temporal resolution. There is also considerable evidence that age-related declines in attentional ability, specifically executive con-

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

trol over the ability to ignore distractions, also contribute to older adults′ difficulties in understanding speech in noise (Tun, 1998; Tun and Wingfield, 1995, 1999). A similar breakdown in inhibitory processes has been implicated in other dual-task and multi-tasking situations. For example, visual distracters during reading may impact older adults more severely than young adults (Connelly, Hasher, and Zacks, 1991), talking on a cell phone while driving may be more hazardous for older adults than for young adults, and closed captioning of television broadcasts may be less helpful for older adults than for young adults (Tun, Wingfield, and Stine, 1991).

For example, Tun, O′Kane, and Wingfield (2002) asked young and older English-speaking adults to listen to lists of words while ignoring competing speech. They varied whether the competing speech was meaningful (read in English) or meaningless (read in Dutch by the same speaker). Although young adults were capable of ignoring the competing speech, the older adults′ recall of the target words was severely impaired by the competing speech. This competing speech effect was greater for older adults when the competing speech was in English than when it was in Dutch (a language that closely resembles English phonology and prosody), suggesting that the effect is due to attentional factors. Indeed, controlling for hearing acuity did not eliminate this effect. Tun et al. conclude that young adults are able to filter out competing speech whereas older adults are less able to do so.

One exception to the general finding that older adults experience greater dual-task costs is a recent study of older adults′ ability to perform simple tasks while talking (Kemper, Herman, and Lian, in press). They compared three motor tasks: simple finger tapping, complex finger tapping, and walking. Surprisingly, Kemper et al. report that young adults exhibited greater dual-task costs than the older adults. Analyses of young adults′ language samples revealed reduced sentence length, grammatical complexity, and propositional content when talking while performing the motor tasks. In contrast, the older adults spoke more slowly during the dual-task conditions but their grammatical complexity and propositional content did not vary with dual-task demands. Based on these findings, Kemper et al. hypothesized that older adults, in response to age-related loss of processing speed and working memory capacity, have developed a restricted speech register that is buffered from many dual-task costs associated with simple motor and concurrent selective ignoring tasks.

However, when the walking task is only slightly more challenging (Kemper, Herman, and Nartowicz, 2002), older adults′ speech quickly deteriorates. When asked to walk, talk, and carry a sack of groceries, older adults′ rate of speaking slows further, and they use many more fillers such as “well” and “you know” to break their speech into short phrases

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

and fragments. These fragments lack key elements of grammatical structure such as auxiliary verbs. Under similar conditions, young adults reduce their speech rate to accommodate for the increased task demands. Kemper et al. suggest that combining two tasks such as walking while talking falls within the range of older adults′ reserve capacity, but task demands can quickly exceed their cognitive reserve capacity, whereas young adults can draw on sufficient reserve capacity to cope with the additional task demands. The idea of cognitive reserve capacity (Satz, 1993) is intended to capture the notion that trade-offs between two or more tasks may be revealed only when the tasks are performed under sufficiently challenging conditions. This concept of reserve capacity has proved useful for characterizing cognitive limits in older adults (Baltes and Baltes, 1980; Baltes, Dittmann, and Kliegl, 1986).

Implications for Technology

Although technology cannot increase older adults′ reserve capacity, it can help minimize demands on it. FM broadcast systems, induction loops, and infrared systems, sometimes provided in public places such as concert halls, theaters, churches, and conference centers, may aid individuals who are hard of hearing by reducing or eliminating dual-task demands arising from poor acoustics, background noise, and competing voices and sounds. These systems typically require the listener to use a special receiver (some hearing aids can be tuned to pick up the signal generated by induction loops) to pick up a signal generated by a special microphone, amplifier, and transmitter.

Other forms of technology may also reduce dual-task demands and aid communication with older adults. Consider noise-dampening headphones. These devices are marketed for frequent travelers but they may also prove helpful for older adults. In one pilot study (Kemper, unpublished manuscript) it is suggested that older adults benefit from using noise-dampening headphones during reading. Older adults were tested in a small group in an ordinary classroom, acoustically “cluttered” by noise generated by the other participants, undergraduates passing by in the hallway, and a noisy ventilation system. When they wore noise-dampening headphones, their reading speed increased 20 percent and their comprehension improved approximately 15 percent. Young adults showed no improvement. Noise-dampening technology might benefit older adults in other situations, such as driving, writing, or preparing tax returns.

Voice-to-text technology might also benefit older adults by minimizing dual-task demands in situations where they are attending to speech while trying to remember or record details—such as names, phone num-

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

bers, and directions. Coupling the display and storage capacity of cell phones with automated speech-to-text capabilities could enable older adults to focus their attention on listening comprehension rather than on the need to find paper and pencil to record a name or a phone number, thus turning a dual-task situation into a single-task situation.

TECHNOLOGY TO EMPOWER OLDER ADULTS

Having covered some basic human needs, in this section we illustrate potential uses of communication technologies to address some of the needs identified above.

It is noteworthy that a large percentage of communication and computing technologies were originally designed for business uses. Those technologies then migrated to the consumer space once volume production allowed for the sale of the devices at significantly lower prices than those paid by the business “early adopters.” Cellular phones were originally designed as a business tool, first tested in 1979. Personal digital assistants (PDAs) were first introduced into the business marketplace by Apple (the Newton) in 1993. Processing power has increased exponentially for both cell phones and PDAs since their launch in the business arena. Our thesis is that there is a significant opportunity to use these inexpensive, mass-produced, and very powerful devices to better serve the communication needs of an aging society by tailoring the devices′ increasing processing capabilities to the specific strengths, needs, and capabilities of older users.

The growing power and sophistication of both cellular phones and PDAs present a unique opportunity to look at them as mobile communication and computing devices (MCCDs). Moore′s law (Intel, 2002) is named after Gordon Moore, one of Intel′s founders. He predicted the doubling of transistors in a CPU every couple of years. Moore′s law is now applicable to MCCDs: CPU power and RAM capabilities double every 18 months. The devices can run an increasingly sophisticated range of software applications, using an expanding range of operating systems such as Windows CE, GNU/Linux, and Palm OS. Bandwidth is also increasing rapidly, allowing MCCDs to transfer most of the processing-intensive tasks, such as visual recognition and database storage and retrieval to remote servers to reduce demands on the local device. Battery life is the only area where the rate of improvement is slow.

A major challenge is that communication technology devices have traditionally been designed by young engineers (mostly male) targeting fellow young users. Older adults have traditionally been forced to adapt to these devices. However, some suggestions of how these devices can serve the needs of older adults are beginning to appear. For example,

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

Mann and Helal (2002) have demonstrated how emerging smart cellular phone technology can act as an effective booster of the utility of smart homes and other smart spaces. They present their vision of using smart phones as magic wands that can be used passively as remote control devices and proactively as intelligent companions offering advice, reminders, warnings, and calls for help. In the future, MCCDs, when properly designed, will increasingly have the power to

  • Compensate for older adults′ diminishing physical and mental capabilities. MCCDs can be designed to increase their “assistance level” as the individual′s abilities change due to health conditions or situational factors, for example, by adjusting amplitude as well as pitch to the individual′s hearing loss as well as the specific room acoustics.

  • Emulate lost capabilities, such as a sense of direction. Some MCCDs are now able to use the global positioning system (GPS). A GPS-capable device can tell a user where he or she is (from a latitude and longitude perspective) with high accuracy. What is relevant here is the device′s ability to correlate where the user is with what else is geographically close to the user to indicate a possible match or to make inferences that would compensate for a memory lapse: “You are near Mary′s house. Do you need directions to get there?”

  • Enhance current abilities, such as hearing or memory retrieval. An MCCD can assist the user by inconspicuously boosting the sound reception of the user. The device′s camera might be used to match pictures of people at a meeting with their names and a list of past contacts with the user: “Hello Mary, how do you feel after your car accident 6 months ago?”

  • Hide imperfections, such as slower comprehension speed. An MCCD can operate as a real-time recording unit that captures and stores other people′s speech and then feeds it to the user at an appropriate rate and pitch for the user to better participate in the discussion.

  • Reduce complexity, as by revising texts automatically. An MCCD can rewrite, paraphrase, elaborate, or annotate a text, providing background information to aid the reader or listener.

  • Bridge distances, such as networking families. An MCCD can relieve loneliness by linking older adults with their families, social circle, and other caregivers.

  • Replace other single-purpose assistive devices, such as hearing aids, note taking, audio recorders, cameras, etc. High-end MCCDs (such as the Compaq iPaq devices) are increasingly being used to perform multiple functions with a single device. This represents a boon for the user who has less hardware to lug around. On the flip side, this also means

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

that a user with a nonfunctioning MCCD could lose the functionality of multiple single-purpose devices.

  • Represent older adults to the world as more competent individuals than their abilities allow them to appear unassisted. MCCDs bring older adults the opportunity to have a real-time “cheat sheet” technology available. Just as business executives learn to rely on their electronic “gizmos” to become more productive, older adults can use MCCDs to leapfrog some of their age-related challenges.

  • Facilitate medical caregiving, by remote telemetry of an older adult by a caregiver. MCCDs are among the few electronic devices that are very close to or on a person′s body during most of the day. These devices can be used to bridge on-the-body medical sensors with remote monitoring systems to give caregivers (and older adults themselves) peace of mind through active monitoring of the physiological signs of older adults.

Although all of the above-proposed features are technologically feasible, they range in potential availability from the short term to the distant future. This availability is predicated on both MCCDs and wireless communication technologies becoming increasingly ubiquitous. The most important barrier to overcome in the development and deployment of MCCDs for older adults is the business model hurdle. There is a definitive need for clear, concise, and defensible business proposals to secure the necessary funding to cover the development, manufacture, and deployment costs of MCCDs for older adults.

Predicting technological advances a few years out is a very risky proposition. A safer approach is to look at the features currently available in desktop personal computers and then to extrapolate when the hardware and software capabilities of today′s MCCDs will be powerful enough to support those features. From this perspective, older adults will be able to acquire, at commodity prices, MCCDs that can

  • convert text to speech and speech to text in real time;

  • utilize nonvisual interfaces such as touch screens and speech recognition software;

  • integrate on-board cameras with easy-to-use software and audiocapture to replace note taking;

  • exploit GPS technology not only to inform people where they are but to remind them where they are going; and

  • render visual information in increasing detail with built-in “zoom” and navigation capabilities.

One of the most exciting potentials of MCCDs is their ability to utilize alternative user interfaces. Highly complex devices such as cars

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

have a standard basic interface. A person can drive nearly any car in the world with the driving skills he or she already has. That is not the case with most new technologies such as televisions, VCRs, microwave ovens, etc. Each such device places a demand on the user to learn the specific device′s user interface features. MCCDs offer a third possibility: MCCDs could be envisioned as “personalized portable user interfaces” where the user controls target devices via the MCCD′s interface, customized to fit the user′s specific communication needs. Emerging research in nonvisual interfaces points toward a future in which older adults can interact with their MCCDs via different modes, depending on the user′s choice: touch, enhanced voice commands (currently available in most new cell phones), and even by reading the lips of an emulated “talking head” on the device′s display. (A talking head in this case is a visual caricature of a person that can simulate the facial expressions of a real person while speaking.)

Challenges to Be Overcome by MCCDs

A major technological challenge is that most MCCDs are becoming fashion statements: Users can choose from the titaniumlike PDAs or leather-clad cell phones. This trend poses some challenges for older adults as MCCDs are becoming ever smaller in overall size, with shrinking keypads and even color displays that are difficult to read under direct sunlight. To be useful to elder users, MCCDs must have clearly legible and audible displays and easy-to-use input devices.

A policy-related challenge is to ensure the privacy of older adults who use MCCDs. There are currently no clear regulations as to who owns the data generated by users of CCDs—for example, GPS coordinates obtained from tracking rental cars, data generated by remote monitoring, or digital telephone recordings. Issues of data privacy, levels of access, and data retention policies need to be addressed. The Health Insurance Portability and Accountability Act (HIPAA) of 1996 is a potential model to follow. For example, older adults must be made aware of the inherent risks of always being trackable, e.g., through cell phone use. HIPAA protects a person′s right to keep his or her medical information private. Recent changes in banking regulations also force banks to seek their clients′ permission before disclosing an individual′s financial data to third parties. Unfortunately, in the area of telephone use, people′s right to the privacy of their own data is not well established.

There are other specific areas that require further research and pending challenges that need to be addressed. In general, there is a need for more translational research to take the massive amounts of academic research and apply some of that knowledge to develop products and ser-

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

vices that are useful to tomorrow′s older adults. From a marketplace perspective, it is not clear that the significant social investment in both industrial and academic research and development has delivered a measurable benefit to America′s older adults.

From a research perspective, there is a need for integrating life-span research on cognitive abilities and the design of adaptive technology so that the technology fits changing cognitive skills. Academics are advised to engage with electronic device manufacturers to build “cognitive flexibility” to ensure that devices will have several built-in operating modes, each of which places a different cognitive load on the user. That flexibility would be best expressed as a function of the percentage of the device′s capabilities that are available to each member of a group of target users with different cognitive capabilities.

From a technological perspective, device manufacturers should pursue a closer alignment with the academic community to design products that address the needs of the growing older population. Such consultation should start at the initial design phase, not just as an add-on or packaging spin. The academic community (under the leadership of an appropriate organization such as NIA) should create a forum for the academic and business communities to come together and collaborate in the development of such user-friendly products and services for older adults. Specifically, the NIA should support the following activities:

  • Fund translational research to transfer the most relevant academic research to private firms interested in developing products and services for older adults.

  • Create an international clearinghouse for the compilation and dissemination of best practices relating to technological design for older adults.

CONCLUSION

We see a bright future for the use of new technologies to address significant communication barriers for older adults. MCCDs can be developed to address key issues, by moderating some of the deleterious effects of elderspeak, alleviating word retrieval problems, and reducing dual- or multi-task demands. MCCDs may also empower older adults by offsetting age-related sensory, physical, and cognitive limitations. However, we also see that these advances will come at some costs:

  • Older adults′ increasing use of technology-heavy devices will expose them to the vagaries of technology, such as frequent reboots, “hung”

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

equipment, electronic tracking, “spam” mail, etc., that have plagued others who use similar devices.

  • Device manufacturers must accelerate the development and commercialization of MCCDs that have truly usable multimodal interfaces, moving beyond the current trend for small graphic and keypad interfaces of today′s devices.

  • Older adults must become more vocal about their specific needs and constructively engage MCCD manufacturers to ensure that new generations of MCCD or similar devices truly meet their needs and expectations.

REFERENCES

Baltes, P.B., and Baltes, M.M. (1980). Plasticity and variability in psychological aging: Methodological and theoretical issues. In G. Gurski (Ed.), Determining the effects of aging on the central nervous system. Berlin: Schering.

Baltes, P.B., Dittmann, K.F., and Kliegl, R. (1986). Reserve capacity of the elderly in agingsensitive tests of fluid intelligence: Replication and extension. Psychology and Aging, 1(2), 172-177.

Bollinger, R., and Hardiman, C.J. (1989). Dementia: The confused-disordered communicatively disturbed elderly. In R.H. Hull and K.M. Griffin (Eds.), Communication disorders in adults (pp. 61-78). Thousand Oaks, CA: Sage.

Burke, D.M., and Laver, G.D. (1990). Aging and word retrieval: Selective age deficits in language. In E.A. Lovelace (Ed.), Aging and cognition: Mental processes, self-awareness, and interventions (pp. 281-300). New York: Elsevier Science.

Burke, D.M., MacKay, D.G., Worthley, J.S., and Wade, E. (1991). On the tip of the tongue: What causes word finding failures in young and older adults. Journal of Memory and Language, 30, 542-579.


Charness, N. (2001). Aging and communication: Human factors issues. In N. Charness, D. Parks, and B.A. Sabel (Eds.), Communication, technology, and aging. New York: Springer-Verlag.

Cohen, G., and Faulkner, D. (1986). Memory for proper names: Age differences in retrieval. British Journal of Developmental Psychology, 4, 187-197.

Connelly, S., Hasher, L., and Zacks, R.T. (1991). Age and reading: The impact of distraction. Psychology and Aging, 6, 533-541.

Cutler, A., and Butterfield, S. (1991). Word boundary cues in clear speech: A supplementary report. Speech Communication, 10(4), 335-353.


Intel. (2002). What Is Moore′s Law? Available: http://www.intel.com/labs/eml [December 3, 2003].


James, L.E., and Burke, D.M. (2000). Phonological priming effects on word retrieval and tip-of-the-tongue experiences in young and older adults. Journal of Experimental Psychology: Learning, Memory, and Cognition, 26(6), 1378-1391.


Kemper, S. (n.d.). Observations on the effects of noise-dampening headphones on meal-time conversations at Greenwood Village, unpublished document. University of Kansas.

Kemper, S., and Harden, T. (1999). Disentangling what is beneficial about elderspeak from what is not. Psychology and Aging, 14, 656-670.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

Kemper, S., Herman, R.E., and Lian, C.H.T. (in press). The costs of doing two things at once for young and older adults: Talking while walking, finger tapping, and ignoring speech or noise. Psychology and Aging.

Kemper, S., Herman, R.E., and Nartowicz, J. (2002). Increasing the costs of doing two things at once. Unpublished manuscript. University of Kansas.

Kemper, S., Jackson, J.D., Cheung, H., and Anagnopoulos, C.A. (1994). Enhancing older adults′ reading comprehension. Discourse Processes, 16, 405-428.


Levow, G.A. (2002). Adaptations in spoken corrections: Implications for models of conversational speech. Speech Communication, 36(1-2), 147-163.


Mann, W., and Helal, S. (2002). Smart phones for the elders: Boosting the intelligence of smart phones. (Report No. WS-02-02). Menlo Park, CA: American Association for Artificial Intelligence.

Morrell, R.W., Dailey, S.R., Feldman, C., Mayhorn, C.B., and Echt, K.V. (2002). Older adults and information technology: A compendium of scientific research and web site accessibility guidelines. Bethesda, MD: National Institute of Aging.


Oticon. (2003). Clear speech. Available: http://otikids.oticon.com/eprise/main/Oticon/com/SEC_AboutHearing/LearnAboutHearing/Products/SEC_OtiKids/Parents/Helping/_Index [December 3, 2003].


Ryan, E.B., Giles, H., Bartolucci, G., and Henwood, K. (1986). Psycholinguistic and social psychological components of communication by and with the elderly. Language and Communication, 6(1-2), 1-24.


Satz, P. (1993). Brain reserve capacity on symptom onset after brain injury: A formulation and review of evidence for threshold theory. Neuropsychology, 7(3), 273-295.

Schneider, B.A., and Pichora-Fuller, M.K. (2000). Implications of perceptual deterioration for cognitive aging research. In F.I.M. Craik and T.A. Salthouse (Eds.), The handbook of aging and cognition (2nd ed., pp. 155-219). Mahwah, NJ: Lawrence Erlbaum.

Seaver, A.M. (1994). My world now: Life in a nursing home, from the inside. Newsweek, June 27, 11-12.

Sit, R.A., and Fisk, A.D. (1999). Age-related performance in a multiple-task environment. Human Factors, 41(1), 26-34.

Sunderland, A., Watts, K., Baddeley, A.D., and Harris, J.E. (1986). Subjective memory assessment and test performance in elderly adults. Journal of Gerontology, 41(3), 376-384.


Tesch-Römer, C. (1997). Psychological effects of hearing aid use in older adults. Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 52B, P127-P138.

Tun, P.A. (1998). Fast noisy speech: Age differences in processing rapid speech with background noise. Psychology and Aging, 13(3), 424-434.

Tun, P.A., and Wingfield, A. (1995). Does dividing attention become harder with age? Findings from the Divided Attention Questionnaire. Aging and Cognition, 2(1), 39-66.

Tun, P.A., and Wingfield, A. (1999). One voice too many: Adult age differences in language processing with different types of distracting sounds. Journals of Gerontology Series B: Psychological Sciences and Social Sciences, 54b(5), P317-P327.

Tun, P.A., O′Kane, G., and Wingfield, A. (2002). Distraction by competing speech in young and older adult listeners. Psychology and Aging, 17(3), 453-467.

Tun, P.A., Wingfield, A., and Stine, E.A. (1991). Speech-processing capacity in young and older adults: A dual-task study. Psychology and Aging, 6(1), 3-9.


Uchanski, R.M., Choi, S.S., Braida, L.D., Reed, C.M., and Durlach, N.I. (1996). Speaking clearly for the hard of hearing IV: Further studies of the role of speaking rate. Journal of Speech and Hearing Research, 39(3), 494-509.


Wahl, H.-W., and Tesch-Römer, C. (2001). Aging, sensory loss, and social functioning. In N. Charness, D. Parks, and B.A. Sabel (Eds.), Communication, technology, and aging. New York : Springer-Verlag.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×

White, K.K., and Abrams, L. (2002). Does priming specific syllables during tip-of-the-tongue states facilitate word retrieval in older adults? Psychology and Aging, 17(2), 226-235.

World Institute on Disability. (1999). Telecommunications problems and design strategies for people with cognitive disabilities. Oakland, CA: World Institute on Disability.

Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 129
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 130
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 131
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 132
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 133
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 134
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 135
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 136
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 137
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 138
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 139
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 140
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 141
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 142
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 143
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 144
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 145
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 146
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 147
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 148
Suggested Citation:"Part III: Domain-Specific Papers -- 5 Addressing the Communication Needs of an Aging Society." National Research Council. 2004. Technology for Adaptive Aging. Washington, DC: The National Academies Press. doi: 10.17226/10857.
×
Page 149
Next: 6 Technology and Employment »
Technology for Adaptive Aging Get This Book
×
Buy Paperback | $67.00 Buy Ebook | $54.99
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

Emerging and currently available technologies offer great promise for helping older adults, even those without serious disabilities, to live healthy, comfortable, and productive lives. What technologies offer the most potential benefit? What challenges must be overcome, what problems must be solved, for this promise to be fulfilled? How can federal agencies like the National Institute on Aging best use their resources to support the translation from laboratory findings to useful, marketable products and services?

Technology for Adaptive Aging is the product of a workshop that brought together distinguished experts in aging research and in technology to discuss applications of technology to communication, education and learning, employment, health, living environments, and transportation for older adults. It includes all of the workshop papers and the report of the committee that organized the workshop. The committee report synthesizes and evaluates the points made in the workshop papers and recommends priorities for federal support of translational research in technology for older adults.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    Switch between the Original Pages, where you can read the report as it appeared in print, and Text Pages for the web version, where you can highlight and search the text.

    « Back Next »
  6. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  7. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  8. ×

    View our suggested citation for this chapter.

    « Back Next »
  9. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!