3
Assessment Methodology for Features for Visually Impaired People

Requirements

Introducing banknote features to allow people who are visually disabled to recognize, denominate, and authenticate U.S. banknotes requires identification of the most effective feature or combinations of features. In general, the feature(s) should be (1) easy to use and reliable; (2) long-wearing, maintaining readability over the life of the banknote; (3) benign, not significantly degrading banknote durability; (4) cost-effective for the BEP to implement; (5) difficult to simulate; and (6) relatively inexpensive for the population to use.

From the large list of possible features assembled by the committee, it is necessary to assess individual features and combinations of features to identify an optimum set that addresses all of these issues. One aspect of evaluating the proposed features is the development of operational meanings for the terms "recognize," "denominate," and ''authenticate" and the determination of how well each feature performs these individual tasks. Figure 3-1 indicates a logical sequence that a person may follow when handed a banknote. First, there is the recognition that the piece of paper is represented by the giver to be a banknote; then, the value of the banknote is determined; finally, the banknote is verified as authentic. In this sequence, the definition of "authentication'' encompasses the definitions of the other two; that is, if a banknote is verified as authentic, it is both determined to be a genuine U.S. banknote (as opposed to another document or counterfeit), and its value is known. Since individual features have varying strengths in identifying either the legitimacy of the banknote or its denomination, these two elements of authentication will be addressed separately. In this report, the term "authenticate" will be restricted to mean to verify a banknote as a genuine U.S. banknote; the term "denominate" will be used to mean to determine the value of the banknote. Lastly, the term "recognize" will be used to mean to differentiate the banknote from other pieces of paper of similar size, for example, store receipts. While it is the primary goal of this committee to recommend features that will help visually disabled people to recognize and denominate banknotes, the committee also evaluated features that will also help them authenticate banknotes.



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--> 3 Assessment Methodology for Features for Visually Impaired People Requirements Introducing banknote features to allow people who are visually disabled to recognize, denominate, and authenticate U.S. banknotes requires identification of the most effective feature or combinations of features. In general, the feature(s) should be (1) easy to use and reliable; (2) long-wearing, maintaining readability over the life of the banknote; (3) benign, not significantly degrading banknote durability; (4) cost-effective for the BEP to implement; (5) difficult to simulate; and (6) relatively inexpensive for the population to use. From the large list of possible features assembled by the committee, it is necessary to assess individual features and combinations of features to identify an optimum set that addresses all of these issues. One aspect of evaluating the proposed features is the development of operational meanings for the terms "recognize," "denominate," and ''authenticate" and the determination of how well each feature performs these individual tasks. Figure 3-1 indicates a logical sequence that a person may follow when handed a banknote. First, there is the recognition that the piece of paper is represented by the giver to be a banknote; then, the value of the banknote is determined; finally, the banknote is verified as authentic. In this sequence, the definition of "authentication'' encompasses the definitions of the other two; that is, if a banknote is verified as authentic, it is both determined to be a genuine U.S. banknote (as opposed to another document or counterfeit), and its value is known. Since individual features have varying strengths in identifying either the legitimacy of the banknote or its denomination, these two elements of authentication will be addressed separately. In this report, the term "authenticate" will be restricted to mean to verify a banknote as a genuine U.S. banknote; the term "denominate" will be used to mean to determine the value of the banknote. Lastly, the term "recognize" will be used to mean to differentiate the banknote from other pieces of paper of similar size, for example, store receipts. While it is the primary goal of this committee to recommend features that will help visually disabled people to recognize and denominate banknotes, the committee also evaluated features that will also help them authenticate banknotes.

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--> Figure 3-1 Logical sequence of banknote verification: recognition-denomination-authentication. The Ideal Feature It is instructive to describe the "ideal" feature for recognizing; denominating; and, if possible, authenticating banknotes as a model to compare with "real" features. The committee gained some insight by summarizing the attributes of an ideal counterfeit-deterrent feature as they were described in previous reports (NRC, 1993; Church and Littman, 1992). These attributes are as follows: difficult to duplicate; difficult to simulate; easily recognized by the general public; durable (i.e., the feature is useful even after considerable wear); easy to produce at low cost; can cocirculate with current banknotes; acceptable to the public (aesthetically pleasing); machine readable; and nontoxic and nonhazardous. While the previous NRC study concentrated on optical or visible features to deter counterfeiting (NRC, 1993), many of these attributes are also desirable in a feature to be used by visually disabled people to recognize and denominate U.S. banknotes. An ideal feature for visually disabled people would also reliably indicate the denomination of the banknote; reliably indicate the orientation of the banknote; address the needs of the whole population, from blind people to the normally sighted; and be easy to use (i.e., not require a device or extended handling).

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--> No feature that the committee evaluated was considered ideal by these criteria, so the committee took the approach of identifying the ability of a given feature or combination of features to satisfy individual criteria, then weighing the relative importance of the evaluation criteria to come up with an optimized set of recommendations. The committee also carried out a similar analysis for devices for denominating banknotes. The discussion of this analysis is found in Chapter 4. Evaluation Strategy The list of features to evaluate was very long, and each feature had several variations. In the present study to evaluate and compare a disparate group of possible features, the committee took a similar approach to that taken in the consideration of counterfeit-deterrent currency features. That is, the committee identified a set of requirements that may be stated initially in vague or general terms, converted the requirements into indicators or criteria; weighted the criteria in terms of their relative importance; and scored or ranked the alternatives with reference to the criteria. In addition to the purely "technical" evaluation described above, the committee considered the target populations for the individual features. A feature that might be of considerable assistance to those with normal or low vision might not benefit blind people at all. Since there may be a relatively large population that would benefit from the feature, the committee chose to recommend that feature despite the fact that it would not be universally useful. The committee also considered features that may be of principal benefit to people who are blind, which might not be particularly useful to those with some vision. The committee attempted to ensure that their list of recommended features provided overlapping coverage, so that each of the target groups would gain significant benefits from the redesigned banknotes if those recommended features were included. Evaluation Framework The committee developed four categories of evaluation criteria: population, function, technical success, and implementation success. Each of these four categories was further subdivided into the criteria against which all proposed features were graded. Figure 3-2 shows the specific criteria in the general categories, and tables 3-1 through 3-4 list the criteria in each group with a short explanation of what is considered "success" for each criterion. The first two general categories are relatively self-explanatory—who will use this feature (population category), and what information about the banknote will the person get using this feature (function category). The third category, technical success criteria, expresses the committee's impression of the ability of the feature to succeed based on technical aspects such as the ease of use, resistance to false positives, etc. The final category, implementation success criteria, takes into account the way that a particular feature would be implemented by the BEP and its impact on circulation.

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--> Figure 3-2 Evaluation criteria used to determine the effectiveness of proposed currency features. For example, punching holes in banknotes, with the number of holes indicating denomination, would be assessed as a general concept in the technical success probability category, with some positive and some negative attributes. In the implementation success criteria category, the shape of the hole (for example, star-shaped, round, or oval) would need to be known for evaluation against criteria such as feature survivability or note durability. The committee's assumption about how a particular feature would be implemented was noted when the feature was evaluated. The various ways a feature could be implemented are discussed in chapters 4 and 6. The committee gave more weight to certain criteria in each category. In the first category, features that would be useful to people who are blind and those with low vision were given more weight. In the function category, the major weight was placed on denomination, as opposed to

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--> Table 3-1 Population Category Category Description of a Successful Feature Blind Blind people can use the feature Low Vision People with low vision can use the feature Normally Sighted, Adverse Lighting Normally sighted people can use the feature in low light Normally Sighted, Normal Lighting Normally sighted people can use the feature in normal light Table 3-2 Function Category Category Description of a Successful Feature Recognition Feature can be used to differentiate banknotes from other similar-sized paper Denomination Feature can be used to determine the value of the banknote Authentication Feature can be used to determine if the note is a genuine U.S. banknote Orientation Feature can be used to orient banknotes for use in vending and other machines authentication, recognition, or orientation. Authentication (in the committee's strict definition) is not thought to be more of a problem for visually disabled people than for the rest of the population, but features that could be used for authentication as well as denomination were rated more highly than features that were only useful for denomination. Orientation of banknotes is necessary for many vending machines and for bank deposits (mostly from businesses, where large amounts of cash are regularly brought into the bank), so it is included as a desirable attribute but not an essential one. In the final two categories, technical success risk and implementation success risk, the criteria were not strictly ranked but were thought of as "high" weight or "low" weight. In the category for technical success criteria, the criteria considered to be most important were reliability of readings; ease of use; compatibility with security features; no requirement for a device other than a person's senses; and resistance to simulation.

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--> Table 3-3 Technical Success Criteria Category Description of a Successful Feature Reliability of Readings Readings do not give "false positives," (i.e., they do not indicate that a note is a denomination other than its true value) or "false negatives" (reject valid banknotes) Ease of Use Feature is easy to use, especially in a situation where there is little time to examine money No Requirement for Device A person's senses can be used to evaluate the banknote, with no requirement for any device or machine Applicability to Current Banknotes Feature could be applied to currency presently in circulation or production without a redesign Compatible with Security Features Feature is compatible with security features scheduled for implementation in the new currency design or recommended in the previous report (NRC, 1993) Ability to Cocirculate Notes can cocirculate with present notes without confusion, misidentification or compromise of automated money-handling machines Resistance to Simulation Feature cannot be easily simulated or corrupted to indicate another denomination Table 3-4 Implementation Success Criteria Category Description of a Successful Feature Unit Cost Unit cost for note production (cost per note) is low Capital Cost Capital cost to BEP and Federal Reserve is low Durability of Banknote The feature will not significantly reduce durability below that of present banknotes Survivability of Feature Feature will serve its intended use after wear and tear of handling and circulation Availability and Manufacturability Technology to manufacture banknotes with the feature is available now Proven Banknote Technology Feature has been used before on banknotes in other countries

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--> In the category for implementation success criteria, the most important criteria were survivability of the feature; durability of the banknote; capital cost; and availability and manufacturability. Capital costs were considered too high at the point where a complete line of additional printing equipment would be required. A new line of equipment may also have an impact on unit costs. Changes to existing operating equipment or modifications to parts of the equipment were considered to be acceptable in terms of capital and unit costs. The list of proposed features was organized generally into groups, including substrate based, edge modification, tactile marking, visual marking, and other. The proposed features were evaluated against the criteria described in these tables, using a "yes," "no," or ''maybe'' to indicate whether the feature met each criterion for success, whether it did not meet the criterion, or whether the committee was not able to evaluate whether the proposed feature met the criterion. For the cost criterion, the full costs of implementation, including costs beyond those incurred by the BEP, were considered to be outside the scope of the present work. The ideal feature for use by visually disabled people would have been rated "yes" in all categories. If a feature was evaluated a no or a maybe for a certain criterion, the committee discussed whether the shortcoming of that feature was a fundamental limitation of the feature or whether the technology required for the feature to be useful and realizable could benefit from further development work. Features that fit into the latter category were noted as candidates for future research (see Chapter 5). Compatibility with security features may be highly important for the near term. Incompatibility with security features proposed for implementation in the long term is not as serious a negative factor, since research and development work to be done for the security feature may determine a way to improve compatibility. Further criteria were needed for any feature that required the use of a device for denominating banknotes. Some features, while not accessible to a person's unaided senses, may make it easier to design a simple and convenient device to denominate banknotes. This type of device could have widespread use in the vending community and may be necessary for those who cannot use other features implemented. Features in this category will be evaluated in Chapter 4, along with features that allow for unaided banknote denomination. The types of devices that the committee envisions will be developed are also discussed in Chapter 4. An additional set of criteria was developed for the evaluation of the devices themselves. When considering the use of devices, the committee identified various criteria that would contribute to successful implementation of a device. In addition, the committee outlined various performance-related criteria that need to be fulfilled when a device is operated in a realistic environment. The criteria for evaluating devices were the following (in no specific order): ability to recognize and denominate; highly accurate; private;

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--> small/portable; low maintenance; inexpensive/good value; rapid response; low power consumption; and long lived. Future development of denomination devices might emphasize the ability to authenticate banknotes as well as to denominate them. The term "inexpensive" is coupled with "good value" to indicate that the amount that a person would be willing to pay for a device is directly related to how useful that device would be. That is, a small, easily used device might be a good value at a higher price than a larger, slower device. If a device receives a satisfactory rating for all of the above criteria, then its operational characteristics for performance should include: a low-false-reject rate; independence of note orientation; an acceptable operating temperature/humidity range; and easy use by untrained/unskilled individuals. These criteria are shown in Figure 3-3 as a diagram, which is similar to that drawn up for feature criteria in Figure 3-2. The form of a device's output characteristics should take into account potential international usage and could be audible (multilingual), tactile, or visual. When discussing many of the above points the committee formed the opinion that the technology could be helpful to people with normal vision using point-of-sale devices, cash accepting machines and automated cash registers, etc. This wider use may well increase the respective market for the units, bringing the prices down and driving the performance upwards. Finally, a list of recommended features was drawn up, with notations as to what questions still need to be answered before implementation. Features were grouped by the way in which a user would get information about the banknote, whether they are visual/tactile (information from both sight and touch), visual only (information from sight), tactile only (information from touch), or machine-readable (information from a device that "reads" the feature and interprets the banknote information for the user).

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--> Figure 3-3 Evaluation criteria for banknote denomination/authentication devices. References Church, S., and D. Littman. 1992. Presentation by Sara Church, Bureau of Engraving and Printing, and Dan Littman, Federal Reserve System, to the Committee on Next-Generation Currency Design. October 21, 1992. NRC (National Research Council). 1993. Counterfeit Deterrent Features for the Next-Generation Currency Design. NMAB-472. National Materials Advisory Board, NRC. Washington, D.C.: National Academy Press.

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