The goal of this study was to investigate the effects of visual degradation on warning symbol comprehension across warning symbol types and age groups. Twenty-seven black and white ANSI symbols of four different types (prohibition, course of action, information, and hazard symbols) were presented to older (N = 21, M = 73.1) and younger adults (N = 20, M = 21.4) via computer at three degradation levels (0%, 30%, 40% of pixels inverted); accuracy and response time in answering yes-no questions about the symbols were recorded. Younger adults were more accurate and faster overall than older adults (p < .01). Regarding degradation, 0% and 30% inverted symbols did not significantly differ in comprehension (p ≥ .25), but both were comprehended better than 40% inverted symbols (p < .01); no interactions were observed. For degraded warning symbols, results suggest symbols must be substantially degraded to affect base comprehensibility, and age differences exist. These data have practical implications for warnings in environments susceptible to degradation.
Get full access to this article
View all access options for this article.
References
1.
BiedermanI. (1987). Recognition-by-components: A theory of human image understanding. Psychological Review, 94, 115–147.
2.
CollinsB. L.DahirM. S.MadrzykowskiD. (1993). Visibility of exit signs in clear and smoky conditions. Fire Technology, 29, 154–182.
3.
MorrowD.G.HierC.M.MenardW.E.LeirerV.O. (1998). Icons improve older and younger adults' comprehension of medication information. Journals of Gerontology. Series B, Psychological Sciences and Social Sciences, 53, 240–254.
4.
EasterbyR. S.HakielS. R. (1981). Field testing of consumer safety signs: The comprehension of pictorially presented messages. Applied Ergonomics, 12, 143–152.
5.
GlasscockN. F.DorrisN. T. (2006). Warning degradation and durability. In WogalterM.S., Handbook of warnings (pp. 499–511). Mahwah, NJ: Erlbaum.
6.
HancockH. E.BowlesC. T.RogersW. A.FiskA. D. (2006). Comprehension and retention of warning information. In WogalterM. S., Handbook of warnings (pp. 267–277). Mahwah, NJ: Erlbaum.
7.
HancockH. E.RogersW. A.FiskA. D. (2001). An evaluation of warning habits and beliefs across the adult life span. Human Factors, 43, 343–354.
8.
HancockH. E.RogersW. A.SchroederD.FiskA. D. (2004). Safety symbol comprehension: Effects of symbol type, familiarity, and age. Human Factors, 46, 183–195.
9.
HancockH. E.RogersW. A.SchroederD.FiskA. D. (2004). [Safety symbol comprehension: Effects of symbol type, familiarity, and age]. Unpublished raw data.
IshidaH.TakahashiT.IdeI.MekadaY.MuraseH. (2007). Generation of training data by degradation models for traffic sign symbol recognition. IEICE Transactions on Information and Systems, E90-D, 1134–1141.
12.
KlineD. W.FuchsP. (1993). The visibility of symbolic highway signs can be increased among drivers of all ages. Human Factors, 35, 25–34.
13.
KlineT. J. B.GhaliL. M.KlineD. W.BrownS. (1990). Visibility distance of highway signs among young, middle-aged, and older observers: Icons are better than text. Human Factors, 32, 609–619.
14.
LeonardS. D.WogalterM. S. (2000). What you don't know can hurt you: Household products and events. Accident Analysis and Prevention, 32, 383–388.
15.
LernerN. D.CollinsB. L. (1983). Symbol sign understandability when visibility is poor. In Proceedings of the Human Factors and Ergonomics Society 27th Annual Meeting (pp. 944). Santa Monica, CA: Human Factors Society.
16.
LeschM. F. (2008). Warning symbols as reminders of hazards: Impact of training. Accident Analysis & Prevention, 34, 1005–1012.
17.
National Electrical Manufacturers Association. (1991). American national standard for criteria for safety symbols (ANSI Z535.5). Washington, DC: Author.
18.
National Electrical Manufacturers Association. (1998). American national standard for criteria for safety symbols (ANSI Z535.5). Washington, DC: Author.
19.
MorrellR. W.ParkD. C.PoonL. W. (1990). Effects of labeling techniques on memory and comprehension of prescription information in young and old adults. Journal of Gerontology: Psychological Sciences, 45, P166–P172.
20.
PeckhamG. M. (2006). An overview of the ANSI Z535 standards for safety signs, labels, and tags. In WogalterM. S., Handbook of warnings (pp. 267–277). Mahwah, NJ: Erlbaum.
21.
Reduced Snelling Chart. Plainsville, MA: The Hillsinger Corporation.
22.
RogersW. A.LamsonN.RousseauG. K. (2000). Warning research: An integrative perspective. Human Factors, 42, 102–139.
23.
RousseauG. K.LamsonN.RogersW. A. (1998). Designing warnings to compensate for age-related changes in perceptual and cognitive abilities. Psychology & Marketing, 15, 643–662.
24.
SchieberF. (1994). Using the “blur tolerance” technique to predict and optimize the legibility distance of symbol highway signs. In Proceedings of the Human Factors Society 31st Annual Meeting (pp. 912–915). Santa Monica, CA: Human Factors and Ergonomics Society.
25.
ShaverE. F.BraunC. C. (2007). Effects of warning symbol explicitness and warning color on behavioral compliance. In Proceedings of the Human Factors and Ergonomics Society 51st Annual Meeting (pp. 290–293). Santa Monica, CA: Human Factors and Ergonomics Society.
26.
TreismanA.GormicanS. (1988). Feature analysis in early vision: Evidence from search asymmetries. Psychological Review, 95, 15–48.
27.
WolffJ. S.WogalterM.S., (1998). Comprehension of pictorial symbols: Effects of context and test method. Human Factors, 40, 173–186.
28.
WongL. T.LoK. C. (2007). Experimental study on visibility of exit signs in buildings. Building and Environment, 42, 1836–1842.
29.
YoungS. L. (1991). Increasing the noticeability of warnings: Effects of pictorial, color, signal icon, and border. In Proceedings of the Human Factors Society 35th Annual Meeting (pp. 580–584). Santa Monica, CA: Human Factors and Ergonomics Society.
30.
ZuckermanA.ChaikenS. (1998). A heuristic-systematic processing analysis of the effectiveness of product warning labels. Psychology & Marketing, 15, 621–642.
