Design of pictograms: a comparison between iterative and non-iterative design methodologies Duarte, M. E. C. 1;2 ; Rosa, C. 2 ; Rebelo, F. 1 & Duarte, C. 2 1. Ergonomics Laboratory. FMH | Technical University of Lisbon. Estrada da Costa. 1499-002 Cruz Quebrada – Dafundo. Portugal 2. IADE | UNIDCOM – Research Unit of Design and Communication / Design School of IADE. Av. D. Carlos I, nº 4. 1200-649 Lisbon. Portugal In this paper we investigate the extent to which iterative and non-iterative design procedures, when conducted by designers without expertise in Ergonomics, are able to generate meaningful pictograms. For this purpose 2 methodologies, used to design pictograms, were compared according to productivity and efficacy. This research had used data from a real project that had the aim to design 24 pictograms for forestal context. The iterative design condition was referred to as Production Group (PG) and the non-iterative was labeled as Individual Production (IP). The pictograms were then evaluated according to their comprehensibility through a Comprehensibility Judgment Test. Results showed that the PG condition had produced the top ranking pictograms (regarding the comprehensibility estimation) 9 times (37.50%) against 5 times (20.83%) of the IP condition and a tied result had occurred 10 times (41.66%). The estimated comprehensibility average of the PG was 37.14% and the IP was 35.42%. According to the t-Student test the difference between the 2 groups’ means was not statistically significant (p-value = 0.491). The results suggest that an iterative procedure to design pictograms could not be cost-effective if the team lacks expertise in Ergonomics and User-Centered-Design methodologies and is not prepared to take advantage of the participant’s contribution. INTRODUCTION Pictograms Pictograms, or pictorial symbols, are warning components that can be used to convey information and to attract attention. Well-designed pictograms have the ability to communicate large amounts of information at a glance and they are a space saving method of displaying information. They can be useful to convey information to persons who cannot read a text, either because of low vision acuity, low verbal skills or insufficient knowledge of the language being used (e.g. Boersema & Zwaga, 1989; Lerner & Collins, 1980). In safety or information/navigation related situations a clear communication is critical, because the lack of understanding, or misinterpretation, could lead to injury, errors and users complaints. Given pictograms important role they should be tested with users for effectiveness (salience, comprehension, etc.). Despite the existence of standards, that describe how to evaluate pictograms comprehensibility, there is no standardized procedure to develop pictograms. Moreover, very little research has evaluated the most used design methods. Ergonomics suggest the User-Centered-Design (UCD) as a project approach to put the intended users at the center of the design. The UCD is characterized mainly by its iterative process of development, where samples of potential users are asked to participate, through specific techniques, directly at key points of the project to make sure that their needs, preferences and abilities are considered. The iterative cycle is composed by activities of analysis, design and evaluation repeated until the intended objectives are attained. The present study aimed to examine to what extent iterative and non-iterative design procedures, when conducted by designers without expertise in Ergonomics, are able to generate meaningful pictograms. For this purpose two methodologies used to design pictograms - Production Group (PG) and Individual Production (IP) - were compared according to productivity and efficiency. In this study, productivity is the quantity of variants produced by each methodology during the given period of time, and effectiveness is operationally defined as the quality of a symbol (as evaluated by subjects in the evaluation stage of the study). The iterative symbol design process There are strong evidences recommending the iterative design process for designing pictograms. In graphical computer interfaces this approach has a great success. The evaluation procedures can be considered to be part of an ongoing, iterative design process, rather than a final testing procedure (Nielson, 1993). Several methods could be used to design pictograms in an