Users' Evaluations of Four Electronic Travel Aids Aimed at Navigation for Persons Who Are Visually Impaired

Article excerpt

Abstract: Eighteen persons with visual impairments evaluated four systematically selected navigation systems. Their performance on 11 tasks, provided ratings, satisfaction on seven aspects of the assistive devices, and explanatory comments show generally valuable functionality and usability, as well as individual marked preferences for various features of different navigation systems.

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Various studies have reported that restrictions in outdoor mobility and independent travel are among the prominent areas of concern in the everyday lives of persons who are visually impaired (that is, those who are blind or have low vision) (Brouwer, Sadlo, Winding, & Hanneman, 2008; Douglas, Corcoran, & Pavey, 2006; Marston & Golledge, 2003). Their process of mobility was depicted by Leonard (1972), who identified two major components: the detection of objects and orientation. Leonard divided orientation into near orientation ("the traveller's ability to maintain his moment-to-moment relationship to the immediate environment") and far orientation ("the traveler's ability to follow a route") (p. 40). Bentzen

This study was funded by a grant from the InSight program of ZonMw. The authors thank all the participants and experts for their valuable contributions and the O&M specialists and employees of Royal Visio for their cooperation. They gratefully acknowledge HumanWare, Optelec, and Wayfinder for lending them the devices. (1997) listed three categories of orientation aids: models, maps, and verbal aids. She hypothesized: "Electronic technology makes it possible to randomly access verbal orientation information such as geographic information systems (GISs), which are electronic databases of spatial information. Coupled with position tracking technology, GISs could revolutionize the way some persons navigate the environment" (p. 284).

Since the introduction of the Global Positioning System (GPS), research projects have investigated its application in combination with geographic information systems for persons who are visually impaired. The Personal Guidance System (Golledge, Marston, Loomis, & Klatzky, 2004), MoBIC (Petrie et al., 1997), and Drishti (Helal, Moore, & Ramachandran, 2001) are apt examples. In 2000, GPSTalk, the first electronic travel aid aimed at navigation, became commercially available (May & LaPierre, 2007). GPS-based systems are widely used for civilian applications, but evidence of their effectiveness for persons who are visually impaired is sparse. In a systematic review, Roentgen, Gelderblom, Soede, & de Witte (2009) found only two such studies. In both studies (Ponchillia et al., 2007; Ponchillia, Rak, Freeland, & LaGrow, 2007), BrailleNote GPS was proved to be effective in locating a target, having time to reorient, and reaching a target location. In addition, Havik, Steyvers, van der Velde, Pinkster, and Kooijman (2010) found improvement in Trekker users' self-reported orientation and mobility (O&M) skills and a change in attitude toward feeling safer and more independent. The purpose of the study presented here was to investigate the functionality and usability of different navigation systems for persons who are visually impaired.

Methods

In fall 2009, we conducted a user evaluation of 4 electronic travel aids. A previous search had revealed 23 devices that persons who are visually impaired can use without environmental adaptations (Roentgen, Gelderblom, Soede, & de Witte, 2008). The devices were classified into two main categories: (1) those aimed at detecting obstacles and orientation (n = 13) and (2) navigation systems (n = 10).

We selected the four navigation devices for the 2009 study on the basis of their availability in the Netherlands, evidence of promising potential (Roentgen et al., 2009), advice from experts, and functionality (Roentgen & Gelderblom, 2008). As a result, we chose the Braille-Note GPS, Trekker, Trekker Breeze, and Wayfinder Access. …