# Exploring the Use of Landmarks to Aid Pedestrian Wayfinding
## 2 Literature  
With the arrival of the smartphone variant of the mobile phone in 2007, pedestrian wayfinding was significantly transformed. Smartphones provide accurate detection and interpretation of users' movements and orientation in real-time by using their inbuilt sensor-based systems, such as the Global Positioning System (GPS), an accelerometer, a gyroscope, and a magnetometer. Nevertheless, GPS is not a perfect system--mobile maps can be drawn or labeled erroneously, so even if the above sensors perform correctly, an incorrect map can still be shown [4]. Aside from occasional map-making errors encountered in mobile maps, two key issues emerge when wayfinding with these systems, namely, (i) the keyhole problem [5,6] and (ii) problems with automated systems. The keyhole problem refers to when elements of interface design restrict the viewing of information on-screen--hindering interface usability. Web browser windows that show cropped portions of images that require a user to resize or scroll the page to display the entire image are an example of this problem. Another example is that some text fields on a website can only accommodate a small section of long words that exceed the field size. In the context of mobile maps, when viewing a map of a large geographic area on a small mobile device, only a small section of the larger map is readily viewable. That is, the user can only perceive a 'keyhole' view of the map. This is shown in Figure 1 below. There are three interrelated aspects to this problem with mobile maps: (i) the small size and the unstable nature of the map presented on-screen [11]; (ii) the high interaction cost of manipulating the interface to view the map proper; and the related (iii) view-change cost, where shifts between global and local views need to be understood [12]. Map instability occurs due to the GPS-based mobile maps moving to correspond with the user's position or viewing direction and the zoom-in, zoom-out aspect of mobile maps. Interaction cost refers to the number of screen-based interactions a person has to complete  
Figure 1: The keyhole problem demonstrated. Map data © 2015 Google. in order to complete a task within an interface. A high interaction cost complicates the task [13]. It is possible that contemporary mobile maps may have a lower interaction cost than earlier versions, such as what was used in earlier studies (e.g., [9; 11]). Before route directions zoomed-in to upcoming turns in turn-by-turn mode, users needed to zoom in and out of the map much more frequently to increase the details of the maps. The second key problem when using mobile maps for wayfinding is relying on the automated route directions. Automation is often described as a labor-saving process that can extend or aid human capability. However, automation can also be a \"thinking-saving\" process where users implicitly trust a system that may fail--with users lacking the ability to deal with the situation. In the case of automated mobile maps, should they malfunction, the wayfinder may not be aware of the current location and might become disoriented or lost. However, when using a paper map to plan a route, the user engages in several cognitive processes to make sense of the map in relation to the surroundings. [PERSON] [14] outlines several theories underlying those processes. Three of those are of interest here, namely map rotation, self-location, and visualization, all of which highlight the differences between using paper maps and mobile maps. With map rotation, cartographic tradition prescribes that a \"north-up\" orientation be used when creating paper maps. This means that in order to relate the map to the environment, the map is rotated, either physically or mentally, to align with the surroundings [15]. This transforms the map from being allocentric, where the spatial relations between objects in a region are described, to egocentric, where the spatial relations between the map user and objects are described [16].