Age-related differences in warning symbol comprehension and training effectiveness: effects of familiarity, complexity, and comprehensibility

Age-related changes in selective attention, inhibitory efficiency, and the ability to form new associations suggest that older adults may have greater difficulty with more complex and less comprehensible symbols. We examined comprehension of symbols varying in terms of ratings of familiarity, complexity, and comprehensibility, by younger (aged 18-35) and older (aged 55-70) adults. It was found that older adults have greater difficulty than younger adults in comprehending warning symbols and that accident scenario training improves comprehension. Regression analyses indicated that familiarity and comprehensibility were important in determining performance on the pre-training comprehension test by both younger and older adults. However, training eliminated the effects of stimulus characteristics for younger adults, while older adults' comprehension continued to be significantly influenced by comprehensibility. We suggest that symbol design incorporates cues to knowledge to facilitate the linkage between new knowledge (i.e. the warning symbol) and relevant knowledge in long-term memory. Statement of Relevance: Symbol characteristics play an important role in age-related differences in warning symbol comprehension. To optimise comprehension by older adults, symbols should have a clear relationship with areal-world referent. Alternatively, symbol design could incorporate cues to knowledge to facilitate the linkage between new knowledge and relevant knowledge in long-term memory.     

Safety symbol comprehension: effects of symbol type, familiarity, and age

A new procedure for evaluating symbol comprehension, the phrase generation procedure, was assessed with 52 younger and 52 older adults. Participants generated as many phrases as came to mind when viewing 40 different safety symbols (hazard alerting, mandatory action, prohibition, and information symbols). Symbol familiarity was also assessed. Comprehension rates for both groups were lower than the 85% level recommended by the American National Standards Institute. Moreover, older participants' comprehension was significantly worse than younger participants', and the older adults also generated significantly fewer phrases. Generally, prohibition symbols were comprehended best and hazard alerting symbols worst. In addition, symbol familiarity was positively correlated with symbol comprehension. These findings indicate that important safety information depicted on signs and household products may be misunderstood if presented in symbolic form. Furthermore, certain types of symbols may be better understood (e.g., prohibition symbols) than other types (e.g., hazard alerting symbols) by both younger and older individuals. These findings signify the utility of the phrase generation procedure as a method for evaluating symbol comprehension, particularly when it is not possible or desirable to provide contextual information. Actual or potential applications of this research include using the phrase generation approach to identify poorly comprehended symbols, including identification of critical confusions that may arise when processing symbolic information.     

A comparison of two training methods for improving warning symbol comprehension

This study compared the effectiveness of two different types of training in improving comprehension of warning symbols by younger (aged 20-35 years) and older adults (aged 50-70 years). The verbal label training paired the symbol with a label describing its meaning while the accident scenario training further expanded on the nature of the hazard, the required/prohibited actions, as well as the possible consequences of failing to comply. Contrary to prior research (e.g., [Lesch, M.F., 2003. Comprehension and memory for warning symbols: age-related differences and impact of training. J. Safety Res. 34, 495-505]), there was no difference in comprehension for younger and older adults prior to training, with both groups only obtaining about 40% correct responses. Both types of training improved performance on a subsequent comprehension test. However, the accident scenario training produced a higher percentage of correct responses, greater confidence in those responses, as well as a longer-lasting reduction of reaction times. In order to further improve symbol design, as well as training to address comprehension difficulties, future research should more closely examine symbol characteristics that influence comprehension.     

The effects of age on symbol comprehension in central rail hubs in Taiwan

The purpose of this study was to investigate the effects of age and symbol design features on passengers' comprehension of symbols and the performance of these symbols with regard to route guidance. In the first experiment, 30 young participants and 30 elderly participants interpreted the meanings and rated the features of 39 symbols. Researchers collected data on each subject's comprehension time, comprehension score, and feature ratings for each symbol. In the second experiment, this study used a series of photos to simulate scenarios in which passengers follow symbols to arrive at their destinations. The length of time each participant required to follow his/her route and his/her errors were recorded. Older adults experienced greater difficulty in understanding particular symbols as compared to younger adults. Familiarity was the feature most highly correlated with comprehension of symbols and accuracy of semantic depiction was the best predictor of behavior in following routes.     

Comprehension and redesign of recently introduced water-sport prohibitive symbols in South Korea

The goal of this study is to evaluate the comprehensibility of recently introduced water-sport prohibitive symbols by the Ministry of Knowledge Economy (MKE, now the Ministry of Trade, Industry and Energy) of South Korea, and to redesign the poorly comprehended symbols based on participants' feedback and three universal ergonomic principles. Evaluation of comprehensibility and cognitive features of fourteen water-sport prohibitive symbols were conducted with forty Korean participants. Only two out of fourteen symbols have comprehension rates higher than the level recommended by ISO standard. Four poorly comprehended symbols are redesigned based on ergonomic design principles and participants’ feedback. A follow-up experiment with another group of twenty Korean participants was conducted to verify the effectiveness of the redesign process and results showed redesigned symbols have better adherence to ergonomic design principles and enhanced comprehensibility than the original ones. The findings may serve as a useful input for researchers and designers in creating easily comprehended symbols to promote safety.Relevance to industryWarning symbols have long been used as an interface to communicate critical situation-specific information to prospective users in industrial undertakings so that the risk of accidents and injuries can be reduced. The findings of this study provide useful information for designers in developing easily comprehended symbols to promote safety.     

The effects of 3D interface metaphor on older adults’ mobile navigation performance and subjective evaluation

Navigating vast information spaces through mobile interfaces has become a common activity in older adults' everyday lives. Studies suggested that interface metaphors could be used to facilitate users' metal model development and information processing when using mobile technologies. However, we know little about how metaphors affect older adults' mobile navigation behavior, and which user characteristics matter during this perceptual and cognitive process. To investigate this, a card interface with a 3D metaphor and a list interface without 3D metaphors were compared among twenty-two participants when performing four navigation tasks. User characteristics including demographic factors, technology experience, and user capabilities were examined. The participants' navigation performance and subjective evaluations were measured as the dependent variables. From the results, we recommend the list interface without 3D metaphors as a beneficial choice for older adults. It performed better in navigation performance, although the differences are not statistically significant. Moreover, navigation performance using the card interface with a 3D metaphor was significantly associated with participants' perceptual speed, thus this interface may be more sensitive to capability declines. Valuable insights into the older adults’ mobile navigation performance and preferences are discussed and important implications for the design of mobile navigation user interfaces are proposed based on the results.Relevance to industryThe experimental results propose a more beneficial way to present contents on a mobile user interface for older adults and provide valuable insights for the designers and industry to help them understand the older adults’ usage and perceptions towards the application of 3D metaphors when navigating with mobile interfaces.     

Traffic sign symbol comprehension: a cross-cultural study

The objective of this study was to evaluate the comprehension levels of highway traffic sign symbols used in different countries, to identify underlying rules that affect comprehension levels, and recommend approaches to deal with the problem. The need for such an evaluation was based on today's travel culture where people are often licensed in one country and then drive—without any further training—in another country. We compared the comprehension levels of different traffic sign symbols in four countries with moderate to high levels of motorization: Canada, Finland, Israel, and Poland. Five different driver populations were sampled in each country: novice drivers, college students, tourists, problem drivers, and older drivers. There were large differences in comprehension among specific sign messages, different countries, and different driver populations. Signs were comprehended best when they were consistent with general ergonomic guidelines for display design as they relate to spatial compatibility, conceptual compatibility, physical representation, familiarity, and standardization. Illustrations of compliance with these principles and violations of these principles are presented, and their implication for traffic safety are discussed. Specific recommendations for sign design that is compliant with ergonomic principles, and for greater international cooperation in sign symbol design are made.     

An evaluation of warning habits and beliefs across the adult life span

Beliefs about warnings and habits associated with reading them were assessed for 863 individuals of various ages. Information gathered for various common household products included (a) how frequently people attend to warning information, (b) the degree of risk they believe is involved during product usage, and (c) how important they believe warnings are for different product types. Also assessed were perceived helpfulness and comprehension for symbols commonly found on product labels or on signs in the environment. Respondents 55 years and older reported reading product warnings more frequently than did younger adults, although they generally perceived warnings as less important. However, no overall age-related differences were found for perceived level of risk involved in using different product types. Although older adults generally perceived symbols to be very helpful when using a particular product, their comprehension levels were poorer than those of younger adults for half of the symbols. Overall, these data suggest that adults of all ages do read warnings on a variety of product types and that they believe warning information is important. This research illustrates the importance of including older adults in usability studies during the development of warning systems, given age-related effects may be associated with some aspects of the warning processing but not others.     

Comprehensibility of universal healthcare symbols for wayfinding in healthcare facilities

Healthcare facilities are often complex and overwhelming for visitors, and wayfinding in healthcare facilities can be challenging. As there is an increasing number of global citizens who travel to seek medical care in another country, it is critical to make wayfinding easy for visitors who are not familiar with the language in a foreign country. Among many wayfinding aids, symbols are helpful for those visitors who have limited ability to understand written language. This study tested universal healthcare symbols in the United States, South Korea, and Turkey to compare the comprehension of symbols cross-country and identify predictors of the correct comprehension. To explore statistically significant relationships between symbol comprehension and countries, Pearson's Chi-square tests, logistic regression, and ANOVA were conducted. The test results showed that ten symbols among 14 tested have significant relationship with countries. Results of this study demonstrate that symbol comprehension can be varied significantly in different countries.     

Effects of label format on knowledge acquisition and perceived readability by younger and older adults

This research examines consumers' information acquisition and preference for labels of a simulated over-the-counter (OTC) medication. Twelve otherwise identical OTC drug bottles were compared with different back labels varying in (a) print size, (b) amount of white space between text, and (c) label design (standard vs extended/pull-out). A no back label condition served as a control. Older (mean age=77.7 years) and younger (mean age=21 years) adults were given one of the 12 bottles and asked to perform one of two information acquisition tasks: (a) they examined the bottle for 3 minutes and then completed a questionnaire with the bottle absent, or (b) they answered the same questionnaire while the bottle was present. Afterwards, participants were given all of the bottles and asked to rank them according to perceived readability. The younger adults' information acquisition performance was significantly better than the older adults' for all label conditions except the control condition where both groups' low performance did not differ. Specifically, the older adults' performance was significantly better in the medium and large print conditions than in the small print conditions - with the latter conditions not differing from the control condition. Younger adults showed no performance differences among the different print-size conditions. No substantial effects on knowledge acquisition performance from the white space manipulations were found. However, the perceived readability ranks showed that both groups preferred larger print size and white space. The white space effect was smaller than for print size, particularly for older adults. The extended/pull-out label design was facilitative for older adults in that it allowed the use of larger print. The results suggest that older consumers may be unable to acquire information in the ‘fine’ print frequently found in various kinds of product literature.     

How In-Home Technologies Mediate Caregiving Relationships in Later Life

In-home technologies can support older adults' activities of daily living, provide physical safety and security, and connect elders to family and friends. They facilitate aging in place while reducing caregiver burden. One of older adults' primary concerns about in-home technologies is their potential to reduce human contact, particularly from cherished caregivers. In this exploratory in situ study, we provided an ecosystem of networked monitoring technologies to six older adults and their caregivers. We analyzed the amount and content of communication between them. The amount of noncomputer-mediated communication did not decrease through the 6-week study. The content of communication coalesced into four themes: communication about the technologies, communication facilitated by technologies, intrusiveness of technologies, and fun and playfulness with the technologies. Results suggest that in-home technologies, designed with sensitivity to older adults' primary motivations, have the potential to shape and tailor important relationships in later life.     

Change blindness in pilot perception of METAR symbology

ObjectiveTo assess General Aviation (GA) pilots' perception of changes in aviation routine weather report (METAR) symbols.MethodSixty instrument-rated GA pilots were randomly assigned to one of three METAR symbology groups. We assessed pilots' ability to detect changes to the METAR symbols during a simulated flight, and examined the relationship between detection performance and pilots' flight behavior, cognitive engagement, and decision making.ResultsDepending on the symbology, pilots varied considerably in their overall detection of METAR symbol change during flight. Pilots who detected the METAR-symbol changes differed in their cognitive engagement compared to pilots who did not detect the changes.ConclusionWeather presentation symbology affects pilots' perception of symbol change and cognitive engagement.Relevance to industryThe simulation outcome provides important data on the perception of weather-presentation symbology important to the design and optimization of cockpit weather displays.     

An empirical investigation into the design of auditory cues to enhance computer program comprehension

Decades of research have led to notable improvements in the representations used to aid human comprehension of computer programs. Much of this research has focused on visual representations, which leaves open the question of how best to design auditory representations of computer programs. While this question has particular relevance for visually impaired programmers, sighted programmers might also benefit from enhanced auditory representations of their programs. In order to investigate this question empirically, first, we introduce artifact encoding, a novel approach to rigorously measuring the comprehensibility of auditory representations of computer programs. Using this approach as a foundation, we present an experimental study that compared the comprehensibility of two alternative auditory program representations: one with lexical scoping cues that convey the nesting level of program statements, and another without such scoping cues. The results of our first experiment validate both artifact encoding and the scoping cues we used. To see whether auditory cues validated through our paradigm can aid program comprehension in a realistic task scenario, we experimentally compared programmers' ability to debug programs using three alternative environments: (1) an auditory execution environment with our empirically derived auditory cues; (2) an auditory execution environment with the current state-of-the-art auditory cues generated by a screen reader running on top of Microsoft Visual Studio; and (3) a visual version of the execution environment. The results of our second experiment showed that our comprehensible auditory cues are significantly better than the state-of-the-art, affording human performance approaching the effectiveness of visual representations within the statistical margin of error. This research contributes a novel methodology and foundational empirical data that can guide the design of effective auditory representations of computer programs.     

Education and working life: VET adults' problem-solving skills in technology-rich environments

The rapidly-advancing technological landscape in the European workplace is challenging adults' problem-solving skills. Workers with vocational education and training need flexible abilities to solve problems in technology-rich work settings. This study builds on Finnish PIAAC data to understand adults' (N = 4503) skills for solving problems in technology-rich environments. The results indicate the critical issue that more than two thirds of adults with vocational education and training have weak skills or lack the skills in solving problems in technology-rich environments and that more than one fifth of these adults are at risk. Furthermore, this study indicates that the likelihood of having fragile problem-solving skills is six times higher for adults with vocational education and training than for adults with at least upper secondary qualification. Since the need for problem-solving in technology-rich environments is likely to increase in the future, this study also identifies the indicators for problem-solving skills differences. The models predicting problem-solving skills on the basis of theoretical assumptions as well as empirical support are presented. Our results indicate that adults' lower performance does not seem to be associated with the vocational education and training educational system itself, but is mostly due to age, education in years, occupation, and gender, as well as work-related and everyday life factors. In practice, the models help to develop new approaches to enable novel problem-solving skills in technology-rich environments based on the current European workplace needs.     

Effects of sign characteristics and training methods on safety sign training effectiveness

This study investigated whether or not training methods affected the effectiveness of symbol training and if there were any relationships between sign symbol characteristics and training effectiveness. Altogether, 26 Mainland China industrial safety signs were used and 60 participants were randomly assigned into four equal-sized groups of control, paired-associate learning, recall training and recognition training. The result was that participants from all the training groups showed significantly greater improvement in comprehension performance than those in the control group, indicating that the training methods improved comprehension of the meaning of safety signs. Participants from the recall training group performed better in the post-training test than those from other training groups. It seems that the recall task elicited a deeper level of learning than the recognition task and that questioning and feedback had a positive effect on training effectiveness. The results also showed that sign characteristics had no significant influence on training effectiveness. It was concluded that recall training is more effective in enhancing comprehension of industrial safety signs than paired-associate learning or recognition training. The findings of this study provide a basis for useful guidelines for designing symbol-training programmes and for designing more user-friendly safety signs.

Statement of Relevance: The present study shows that recall training was more effective in improving comprehension of industrial safety signs than paired-associate learning or recognition training and cognitive sign features did not influence training effectiveness. They provide a basis for useful guidelines for designing symbol-training programmes and for designing more user-friendly safety signs.     

Narrowing the age-based digital divide: Developing digital capability through social activities

Healthcare information technologies (HIT) have shown great potential for improving the effectiveness and quality of healthcare services. However, the inequal ability of older adults to use HIT may limit their exploitation of these benefits. To narrow the age-based “digital divide”, this research further develops the concept of digital capability and emphasises the link between older adults and their social context. Based on a qualitative inductive study of 33 participants, who included Chinese patients and their family members, we generate a novel theoretical model for understanding the process by which social activities may shape older adults' digital capabilities. Based on the model, we suggest two strategies that might encourage older adults to engage with HIT. This research contributes to the information systems (IS) literature by strengthening digital capability as a conceptual lens to investigate individuals' engagement with information communication technologies (ICTs). It also extends research on the social context for ICT use by revealing how social processes at multiple levels influence digital capability development. Finally, this study offers practical implications for governments and private sectors to encourage and promote ICT use by older adults.     

Hong Kong Chinese and Korean comprehension of American security safety symbols

This research evaluated Hong Kong Chinese and Korean comprehension of American security safety symbols, and how successfully they could guess the meaning of the symbols in relation to their ratings of the appropriateness of the design of each of the symbols. Symbol comprehension scores, symbol guessing scores, design appropriateness ratings, and demographic information were obtained for 81 Hong Kong Chinese and 60 Koreans. For all the symbols tested, comprehension scores for the Hong Kong Chinese and Koreans were much lower than for Americans. The finding that Americans were better at interpreting American symbols than Hong Kong Chinese and Koreans indicates that problems are likely to arise if such symbols are used by non-Americans. Gender did not affect guessing performance, and success at guessing symbols was not related to the subjective ratings of design appropriateness for the symbols. The findings here reveal the importance of developing security safety symbols with the end users in mind.

Relevance to industry

Designing effective pictorial security safety symbols to cover the many potential situations and scenarios for a specific population is a difficult business. The findings of this study underline the importance of developing security safety symbols with the end users in mind. The results provide useful information to assist in the design of more user-friendly security safety symbols.     

Traffic sign symbol comprehension: a cross-cultural study

The objective of this study was to evaluate the comprehension levels of highway traffic sign symbols used in different countries, to identify underlying rules that affect comprehension levels, and recommend approaches to deal with the problem. The need for such an evaluation was based on today's travel culture where people are often licensed in one country and then drive--without any further training--in another country. We compared the comprehension levels of different traffic sign symbols in four countries with moderate to high levels of motorization: Canada, Finland, Israel, and Poland. Five different driver populations were sampled in each country: novice drivers, college students, tourists, problem drivers, and older drivers. There were large differences in comprehension among specific sign messages, different countries, and different driver populations. Signs were comprehended best when they were consistent with general ergonomic guidelines for display design as they relate to spatial compatibility, conceptual compatibility, physical representation, familiarity, and standardization. Illustrations of compliance with these principles and violations of these principles are presented, and their implication for traffic safety are discussed. Specific recommendations for sign design that is compliant with ergonomic principles, and for greater international cooperation in sign symbol design are made.     

Why Taddeo and Floridi did not solve the symbol grounding problem

The symbol grounding problem (SGP), which remains difficult for AI and philosophy of information, was recently scrutinised by Taddeo and Floridi (Solving the symbol grounding problem: A critical review of fifteen years of research. Journal of Experimental & Theoretical Artificial Intelligence, 17, 419–445, 2005; A praxical solution of the symbol grounding problem. Minds and machines, 17, 369–389, doi:10.1007/s11023-007-9081-32005, 2007). However, their own solution to SGP, underwritten by Action-based Semantics, although different from other solutions, does not seem to be satisfactory. Moreover, it does not satisfy the authors' principle, which they dub ‘Zero Semantic Commitment Condition’. In this paper, Taddeo and Floridi's solution is criticised in particular because of the excessively liberal relationship between symbols and internal states of agents, which is conceived in terms of levels of abstraction. Also, the notion of action seems to be seriously defective in their theory. Due to the lack of the possibility of symbols to misrepresent, the grounded symbols remain useless for the cognitive system itself, and it is unclear why they should be grounded in the first place, as the role of grounded symbols is not specified by the proposed solution. At the same time, it is probably one of the best-developed attempts to solve SGP and shows that naturalised semantics can benefit from taking artificial intelligence seriously.     

一种TH-UWB信号同步捕获算法研究

针对跳时超宽带（TH-UWB）系统,提出了一种基于特殊训练序列的同步捕获算法,该算法使用宽度为一个信息符号的滑动时间窗对接收信号依次截取,通过设计一种特殊的训练序列使得相邻两段截取信号的相关值仅与时间窗的滑动时延有关,然后利用这种滑动搜索来实现同步捕获参数的估计.这种算法能够有效地捕获密集多径信道下极窄脉冲的能量,并且降低了运算复杂度和同步捕获时间.结果表明,在训练序列长度为16、32时误码性能曲线和理想同步情况下十分接近.