EVALUATING ANSI Z535-FORMATTED WARNING LABELS AS AN INTEGRATIVE SYSTEM

Transcription

1 Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1642 EVALUATING ANSI Z535-FORMATTED WARNING LABELS AS AN INTEGRATIVE SYSTEM Michael J. Kalsher William G. Obenauer Christopher F. Weiss Rensselaer Polytechnic Institute Debate continues regarding the relative effectiveness of the ANSI Z535 guidelines for the design and placement of warnings. Research shows consistent positive effects of these guidelines on precursors to warning compliance (e.g., noticing, reading, intended compliance), but less consistency on compliance behavior. Challenges in interpreting these findings stem from factors such as small sample sizes, varying research designs and experimental conditions, and treating the ANSI Z535 guidelines as a singular entity rather than as an integrative system of separable features. Here, we address these issues by testing perceptions of warning label effectiveness using a large sample (n=533) and systematically manipulating variables cited in the Z535 guidelines. Collectively, we tested eight label designs for a (2-drawer and 4-drawer) file cabinet and found statistically significant relationships between design recommendations from the ANSI Z535 guidelines and perceptions of effectiveness. The presence of a warning header and pictogram exerted the largest effects. Bulleted text and (larger) font size were also related to increased perceptions of effectiveness. Copyright 2016 by Human Factors and Ergonomics Society. DOI / INTRODUCTION Safety signs and labels are an important consideration in product design, primarily to enhance safety, but also in response to the legal precedent that absent an adequate warning, a product may be judged to be defective. When this occurs, a manufacturer and/or other potentially blameworthy entities may be held liable for injuries those products cause (Barrett & Kott, 1994). Product liability lawsuits stemming from failure to warn claims can be costly, often totaling in the millions of dollars (e.g. Levy Konigsberg LLP, 2012). Consumers have pursued failure to warn claims for injuries sustained through the use of or exposure to a wide variety of products, equipment and product-use environments (e.g., City News Service, 2015; Nadolny, 2015; Sandler, 2015; Watts, 2015). Collectively, the ANSI Z535 standards provide a set of guidelines intended to standardize the design and placement of safety signs and labels used to communicate safety and accident prevention information (ANSI, 2011). These guidelines should contribute positively to the quality of safety labels intended to identify and warn against specific hazards. An important role of well-designed safety labeling on products and equipment containing residual hazards (hazards not completely eliminated through design and/or guarding) is to aid end users, among others, in making informed decisions and taking appropriate actions to ensure their personal safety. Presently, the warnings literature is conflicted with regard to the role of the ANSI Z535 guidelines in achieving these outcomes. In this paper, we briefly review conflicts in the literature and then seek to provide some resolution to these conflicts through the results of a study that addresses crucial design inconsistencies that we believe highlight limitations concerning the validity of some previous research findings. Laughery et al. (2002) reported that warning labels that comply with ANSI Z535 guidelines are perceived as more likely to be noticed, read, understood and complied with as compared to non-compliant warnings. An experiment conducted by Smith and Wogalter (2010) provides support for the hypothesis that users are more likely to comply with on-product warning labels that are consistent with ANSI Z535 guidelines than generic warning labels. Conversely, other research suggests that both generic and ANSI-style warning labels are ineffective at inducing compliance in situations where perceived risk is low (Heckman, Harley, Scher, & Young, 2010), and that in some situations older OSHA-style warnings may be more effective than warnings that comport with more recent versions of the Z535 guidelines (Kim & Wogalter, 2009). Shaver et al. (2006) suggested that inconsistencies in the literature might stem from the possibility that people perceive warnings that are compliant with ANSI Z535 to be effective, but that they actually are not. On the surface, their argument appears to be supported by Young, Frantz, Rhoades, and Darnell's (2002) review of the literature summarizing the effectiveness of ANSI Z535 guidelines in experimental studies. Frantz, Young, Rhoades, and Wisniewski (2005) also compared a series of survey data to experimental data in an attempt to illustrate the difference between perceptual and behavioral measures of effectiveness in the literature. Closer examination of specific methodological features (e.g., sample size, subject selection, interpretation of the ANSI guidelines) of these earlier studies may call some of their conclusions into question. The main focus of the present research is to address concerns expressed regarding the predicted compliance studies to which they are compared, rather than potential inconsistencies in compliance experiments. In order to more clearly understand the relationship between predicted and actual compliance, it is important to develop an adequate predicted compliance data set to serve as a benchmark for comparisons against behavioral measures. The ANSI Z535 guidelines outline a system for designing warning labels that includes a variety of recommended features that can be incorporated based upon the specific needs and practicality of a given situation (ANSI, 2011). Previous compliance prediction studies, however, have treated ANSI compliance as a strict binary variable (i.e., ANSI-compliant or

2 Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1643 not ANSI-compliant; see Frantz et al., 2005; Laughery et al., 2002). Shaver et al. (2006) included multiple labels in their study, but the many differences between each of the tested labels make it difficult to isolate the effectiveness of any specific feature recommended in the ANSI Z535 guidelines. This matter is further complicated by the fact that while Shaver et al. (2006) tested a variety of labels for predicted compliance, their small sample size (n=22) limits the generalizability of their findings. Conversely, while Frantz et al. (2005) and Laughery et al. (2002) used larger sample sizes, their use of a binary compliance variable may impose similar limitations. Also, the role of perception of risk in predicted compliance is unclear as Shaver et al. (2006) included only one condition, a two-drawer filing cabinet, in their compliance prediction study. Finally, while other studies (see Frantz et al., 2005; Laughery et al., 2002) have included multiple experimental conditions, the conditions chosen are not directly comparable for the purposes of understanding how differences in perceived risk impacts measures of compliance. This study addresses numerous concerns outlined above. We used a larger collection of warning labels than were used in previous studies. Also, labels were differentiated by a single variable to isolate the relative contributions of different ANSI Z535 recommendations to perceptions of effectiveness. The between-subjects aspect of this study incorporated two different conditions that were strategically chosen to allow incorporation of risk perception into the interpretation of the results. Finally, the larger sample size (n=533), in which all subjects evaluated each label style, addresses concerns raised by the smaller sample sizes employed in previous studies. METHOD This study examined the effects of eight different warning label formats on people s perceptions regarding the likelihood that the labels will be noticed and complied with. Variations in the labels included differences in font size, paragraph format, warning header, presence or absence of a pictogram and style of pictogram. Participants Five hundred thirty-three students from a private university in the Northeast served as study participants. The age of the participants ranged from 17 to 26 years with an average age of 19.4 years. Males accounted for 76.7% of the sample with females accounting for the remaining 23.3%. These participants represented forty-three different primary majors. Design and Procedure Participants were given a six-page packet that contained exemplar instructional warning labels to be placed onto a twodrawer or a four-drawer filing cabinet. The first page of the packet was a consent form. Once signed, the form was removed and stored separately to preserve participants confidentiality. The second page had a picture of either a twodrawer or a four-drawer filing cabinet with the following text: Imagine a situation where someone is setting up the furniture and supplies in their office and one of the things they are unpacking and setting up is a two (or four)-drawer file cabinet like the representation to the right. Next, assume that the person has files to put in the filing cabinet that will take up about three-quarters of one drawer. The next two pages of the packet contained the eight labels to be evaluated. These labels are shown in Figure 1. There were four labels printed per page. Participants were instructed to answer the following questions for each label configuration: 1. How many people out of a hundred (%) do you think would follow the label and load the bottom drawer first? 2. How many people out of a hundred (%) do you think would notice this label? The fifth page requested information about participants familiarity with filing cabinets. They were asked if they owned a filing cabinet, and if they did, to indicate which of four exemplar cabinets it resembled most. The exemplars included wide and narrow versions of two and four-drawer filing cabinets. Participants were given the option to draw their filing cabinet if it did not match one of the exemplars. Participants were also asked if they had been personally injured by a falling file cabinet or had known someone who had, and if so, to provide details of the incident(s). The last page was used to assess participants hazard perceptions concerning a falling file cabinet. A picture of a tipping file cabinet (either a two-drawer or a four drawer filing cabinet) was shown falling towards a person. Participants were asked to estimate the likelihood a person would be injured if struck by the falling file cabinet and to estimate the severity of the injury on 10-point, verbally anchored Likert-type scales. Table 1. Regression Results. Font Size (20 pt = 1) Paragraph Format (Bulleted = 1) Warning Header Pictogram (Present = 1, Baseline = ANSI-format) Modified Pictogram ANSI/ISO Pictogram Dependent Variable constant *** *** (0.534) (0.472) *** *** (0.284) (0.251) *** *** (0.537) (0.486) *** *** (0.908) (0.707) *** *** (0.488) (0.483) * (0.511) (0.516) *** *** (0.497) (0.513) F(6,532) = *** *** R *** p<.001, ** p<.01, * p<.05, Ϯ p<.10

3 Four Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1644 Figure 1.Warning Label Style. 1. Continuous 20-pt Arial font 4. Bulleted 17-pt Arial font. 7. Bulleted 17-pt Arial font, ANSI-style signal word panel, and alternate pictogram (ANSImodified label). 2. Continuous 17-pt Arial font 3. Bulleted 20-pt Arial font. 5. Bulleted 17-pt Arial font, ANSI-style signal word panel. 6. Bulleted 17-pt Arial font, ANSI-style signal word panel, and pictogram (ANSI-original) 8. Bulleted 17-pt Arial font ANSI/ISO blended RESULTS This section discusses significant results in terms of both predicted noticing and predicted compliance. We then progress to discuss the effects of the manipulated variables: font size, paragraph style, warning header, image presence, and image style. A significance criterion of p<.05 was used for all comparisons. Because we collected eight responses from each subject, a fixed-effects regression was used to analyze the data. This method controls for the individual differences of each subject beyond those traits that can be reasonably measured. It also allowed us to isolate the effects of font size, paragraph format, warning headers, the presence of a pictogram, and the style of pictogram. As shown in Table 1, models were significant for the dependent variables of predicted noticing [F(6,532) = , p<.001, R 2 =.349] and predicted compliance [F(6,532) = , p<.001, R 2 =.258]. Significance levels were calculated using robust standard errors. There was a significant difference between all of the labels for predicted noticing with two exceptions. There was no significant difference between the Continuous 20-pt label and the Bulleted 17-pt label. Also, there was no significant difference between the ANSI-original label and the ANSI-modified label. There was a significant difference in predicted noticing between the formatted labels and labels without formatting. There was a significant difference in predicted compliance between all of the labels with two exceptions. There was no significant difference between the Continuous 20-pt label and the Bulleted 17-pt label for the four-drawer packet recipients. There was no significant difference between the ANSIoriginal label and the ANSI-modified label for the two-drawer packet recipients. There was a large gap in predicted compliance between the formatted and unformatted labels. Font Size For both the two and four-drawer conditions, predicted noticing and compliance was higher for the 20-pt than the 17- pt bulleted labels. As shown in Table 2, these differences ranged from 3.5 to 5.6 percent. The regressions analysis showed that the binary variable of font size (20 point = 1) had a positive, significant relationship with both predicted noticing ( = 4.79, SE =.284, p<.001) and predicted compliance ( = 3.98, SE =.251, p<.001). Collectively, these findings show that increased font size has a significant positive relationship with both predicted noticing and predicted compliance. Table 2. Comparison of 20- and 17-point font sizes. 20 point 17 point Diff Paragraph Format Continuous Bulleted Continuous Bulleted Continuous Bulleted Continuous Bulleted Similar to the analyses for font size, style of paragraph formatting was significantly related to both predicted noticing

4 Four Four Four Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1645 and predicted compliance. More specifically, when all other variables are held constant, labels incorporating bulleted texts scored significantly higher on both predicted measures than labels using continuous text. Table 3 shows that these differences ranged from 3.5 to 5.3 percent. Regressions analysis showed that the binary variable of paragraph format (bulleted text = 1) had a positive and significant relationship with predictions for both noticing ( = 4.46, SE =.537, p<.001) and compliance ( = 4.40, SE =.486, p<.001). Table 3. Comparison of bulleted and continuous text. Warning Header Bullet Cont. Diff 17 point point point point point point point point The regression analysis showed that the binary variable of warning header (header present = 1) had a significant, positive relationship with both predicted noticing ( = 24.50, SE =.908, p<.001) and predicted compliance ( = 17.82, SE =.707, p<.001). Only one of the labels tested included the ANSI-style warning header with no pictogram (#5). To illustrate the effectiveness of this label, we compared it only to label #4, which included 17-pt font and bulleted text, but no header. Table 4 shows that for both the two and four drawer conditions, predicted noticing and compliance were significantly higher for label #5 than for #4. The presence of an ANSI-style warning header as compared to its absence appeared to produce greater differences in predicted noticing and compliance (ranging from 18.0 to 25.3 percent) than the previously discussed variables. Table 4. Comparison of orange warning header and no warning header. Warning Header No Header Diff Presence of Image To test the effect of the presence of a pictogram on predicted noticing and compliance, the regression analysis showed that the binary variable of pictogram (pictogram present = 1) had a significant and positive relationship with both predicted noticing ( = 9.23, SE =.488, p<.001) and predicted compliance ( = 9.97, SE =.483, p<.001). Additionally, we compared predicted outcomes for the text only label with an ANSI-style warning header (#5) to the three labels that also contained a pictogram (labels #6-8). In all cases, labels with a pictogram received higher predicted noticing and higher predicted compliance scores. Table 5 shows that the differences in predicted noticing and compliance scores ranged from 8.6 percent to 12.3 percent. These effects are not as large as the ones associated with manipulating the warning header, but they are greater than the effects of manipulating text size or paragraph format. Type of Pictogram Three different pictograms were evaluated in this study. The pictogram in label #6 depicted a filing cabinet falling and was presented in a manner consistent with the ANSI-Z535 guidelines. The pictogram used in label #8 used the same filing cabinet as #6, but it was presented within a yellow triangle, consistent with ISO guidelines. The pictogram used in label #7 included a person. noticing and compliance rates for these configurations are presented in Table 5. Table 5. Comparison of labels with an image to labels without images. No Image Type Image Image Diff vs. ANSI ANSI / ISO ANSI Modified ANSI ANSI / ISO ANSI Modified ANSI ANSI / ISO ANSI Modified ANSI ANSI / ISO ANSI Modified Overall, predicted rates of noticing were higher than predicted rates of compliance. The difference between these predicted rates, however, varied greatly as a function of label characteristics. For example, the difference between predicted noticing and predicted compliance for the continuous 17-point label in the two-drawer file cabinet condition was 6.9 percent. The difference between predicted outcomes for the ANSI pictogram label in the same experimental condition, by contrast, was 13.2 percent.

5 Proceedings of the Human Factors and Ergonomics Society 2016 Annual Meeting 1646 DISCUSSION Previous research by Shaver et al. (2006) concluded that noticing and compliance increase in a linear fashion along with the number of formatting elements. This study shows, however, that while most of the formatting elements tested were significantly related to predicted outcomes, the size of the effects was not consistent. The predicted effects of introducing an ANSI-style warning header, for instance, were greater than the predicted effects of using bulleted text or increased font size. The reported differences in predicted effects should be interpreted cautiously though, as not all variables were tested in the same conditions. For example, the effects associated with the presence of an ANSI-style header were only tested with a bulleted 17-pt font. The consistent use of ANSI-style headers in warning labeling is recommended in the ANSI-Z535 (2011) guidelines and our results clearly supported this recommendation. The guidelines also recommend the use of (properly designed and tested) pictograms whenever appropriate. Here too, our findings provide support for the use of pictograms in safety labeling, although, there was no clear advantage for any of the pictograms tested here. ANSI (2011) provides recommendations for the minimum and ideal font sizes used on warning labels. These recommendations clearly indicate that when practical, the use of a larger font size is generally preferable. The results of this research show that the larger letter size was associated with higher rates of predicted noticing and compliance. The effect size of manipulating this variable, however, was smaller than the effect size of manipulating the presence of a warning header. Consequently, in situations where space is limited, designers of warnings should carefully consider potential tradeoffs. The ANSI-Z535 (2011) guidelines recommend outline format, and even more specifically, bulleted outline format, over continuous font. In testing this recommendation, we found that the use of bulleted text led to higher predicted rates of noticing and compliance, but these differences, while statistically significant, actually accounted for a relatively small proportion of variance. Having said that, there are few tradeoffs associated with utilizing a bulleted outline format, so following this guideline likely has few drawbacks. Label design features are only some of the many factors that can influence compliance with safety warnings. Manufacturers, and other entities who bear responsibility for warning label design and placement, should also carefully consider other factors such as characteristics of the product, likely users, and context when making decisions about any design feature or combination of features for a warning label. CONCLUSION This study took an important step in expanding our knowledge regarding the perceived effects of different aspects of the ANSI-Z535 guidelines. While previous studies had looked at warning labels primarily as being compliant or not compliant, this study examined the perceived effects of a variety of ANSI recommendations as separable features of a safety labeling system. While Shaver et al. (2006) argue that people perceive ANSI labels as effective despite the fact that laboratory studies find conflicting results, we suggest that laboratory studies may not find evidence of the effectiveness of ANSIformatted warning labels because of inconsistent research design and measurement, as well as a tendency to view the ANSI-Z535 guidelines as a singular entity rather than an integrative system of separable design components. Consequently, future research should seek to resolve the conflicting findings in laboratory studies of warning effectiveness in the same way that we have clarified findings regarding the perceived effectiveness of ANSI-Z535 guidelines in this study. REFERENCES ANSI. (2011). ANSI Z American National Standard for Product Safety Signs and Labels. Barrett, M. J., & Kott, D. R. (1994). Warnings: Duty to Retrofit / Subsequent Duty to Warn. In J. L. McGoldrick & F. T. Smith (Eds.), New Jersey Product Liability Law (pp ). Newark: New Jersey Law Journal Books. 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