Tomioka Kei
Design Center, Toshiba Corporation, Tokyo, Japan.
J Physiol Anthropol. 2007 Mar;26(2):159-64. doi: 10.2114/jpa2.26.159.
It is more crucial than ever to consider the elderly when designing products. One of the important things to remember is the legibility of characters, since this influences the accessibility and usability of products. We studied the effects of character attributes on legibility using 70 subjects (60 aged 46-79 with no apparent ocular problems except presbyopia, and 10 aged 68-80 with cataracts). Thirty 10-key television remote control models were made. The characters on each were different, and were based on combinations of three attributes-height (5 levels), thickness (3 levels), and display mode (2 levels; positive: black characters on a white background, negative: white characters on a black background). Participants subjectively evaluated the legibility of the characters for each 10-key sample under two ambient illuminance conditions: 500 lx and 50 lx. They also performed paired comparisons on samples with the same height and thickness but different display modes. Subjective data were analyzed using a three-way factorial ANOVA for character height, thickness, and display mode. Legibility was significantly affected by all factors for those without cataracts under both illuminance conditions, and the interaction between thickness and display mode was significant. A two-way factorial ANOVA was performed for height and display mode for each thickness. Legibility was, in general, better for thinner characters in negative mode and was better in negative mode under dark illuminance for those with and without cataracts. This tendency was more pronounced in the elderly (over 65 years old). Paired comparisons showed that legibility was better in negative mode under both illuminance conditions, especially with medium and thin characters, for those with and without cataracts. Although there are few accounts of the effects of positive and negative modes in various existing guidelines, this finding would suggest that legibility can be enhanced by using the negative mode.
在设计产品时考虑老年人的因素比以往任何时候都更加关键。需要记住的重要一点是字符的易读性，因为这会影响产品的可达性和可用性。我们使用70名受试者（60名年龄在46 - 79岁之间，除老花眼外无明显眼部问题，10名年龄在68 - 80岁之间患有白内障）研究了字符属性对易读性的影响。制作了30种10键电视遥控器模型。每个模型上的字符都不同，基于三个属性的组合——高度（5个级别）、粗细（3个级别）和显示模式（2个级别；正模式：白色背景上的黑色字符，负模式：黑色背景上的白色字符）。参与者在两种环境照度条件下（500勒克斯和50勒克斯）对每个10键样本的字符易读性进行主观评估。他们还对高度和粗细相同但显示模式不同的样本进行配对比较。使用三因素方差分析对字符高度、粗细和显示模式的主观数据进行分析。在两种照度条件下，对于没有白内障的人，所有因素对易读性都有显著影响，并且粗细和显示模式之间的交互作用显著。对每个粗细的高度和显示模式进行双因素方差分析。总体而言，负模式下较细的字符易读性更好，在暗光条件下，无论有无白内障，负模式下的易读性都更好。这种趋势在老年人（65岁以上）中更为明显。配对比较表明，在两种照度条件下，负模式下的易读性更好，尤其是对于有和没有白内障的人来说，中等和细的字符更是如此。尽管在各种现有指南中很少提及正模式和负模式的影响，但这一发现表明使用负模式可以提高易读性。
