Showing papers in "Cartographic Journal in 1979"
TL;DR: This paper found that map-users often fail to obtain an accurate visual image of relief form from contour maps, though little is known about the specific problems experienced by the specific people.
Abstract: Map-users often fail to obtain an accurate visual image of relief form from contour maps, though little is known about the specific problems experienced. A multiple-choice questionnaire given to 701 subjects concentrated upon the ability to identify different types of slope on contour diagrams. Conceptual difficulty existed, but the failure to judge the relative steepness of slope along convex profiles was best explained by recourse to perceptual error. It is concluded that this may be related to Gibson's texture gradient effect.
24 citations
TL;DR: Hill shading and contouring were examined in relation to how they affected the performance of several tasks of map reading and map interpretation as discussed by the authors, and the experimental results revealed that elements which could be related to the terrain, or were aspects of it, could be located more rapidly when shading was present.
Abstract: Hill shading and contouring were examined in relation to how they affected the performance of several tasks of map reading and map interpretation. Evaluation of the experimental results revealed that elements which could be related to the terrain, or were aspects of it, could be located more rapidly when shading was present. Only when the target could not be perceived easily with peripheral vision, did the visual noise in the relief depiction appear to adversely affect performance scores. Thus, while the value of contours is recognised, the graphic continuity and imageability of shading may provide perceptual advantages to the map user in performing a wide variety of map reading tasks.
22 citations
TL;DR: Methods of improving contour maps are discussed and an experiment where conventional contours were compared with contour lines elaborated to produce a 'wedding cake' effect, but this elaboration did not improve performance.
Abstract: Map readers are generally faster and more accurate in interpreting relief from layer tint maps than from contour maps. This paper discusses methods of improving contour maps and reports an experiment where conventional contours were compared with contour lines elaborated to produce a 'wedding cake' effect, but this elaboration did not improve performance. The main problem for adults when reading contour maps may be a difficulty in integrating small areas of relief in order to visualise a larger area. If this is correct, no simple elaboration of contour lines will help the map reader unless it gives contours the conspicuity which layer tint colours have in peripheral vision.
16 citations
TL;DR: The numerous information processing activities thought to accompany this visually induced synthesis are examined from a cartographic point of view with particular attention paid to the roles of Brief Visual Storage, Short Term Memory and Visual Conspicuity.
Abstract: Visual communication of cartographic displays requires that the reader attend to and extract information from a display during visual examination. The reader must process these visual inputs into concepts and also blend these fixation based inputs into a composite of the original image in order to come to some conception of the displayed message. The numerous information processing activities thought to accompany this visually induced synthesis are examined from a cartographic point of view with particular attention paid to the roles of Brief Visual Storage, Short Term Memory and Visual Conspicuity. The processes that occur during visual search reduce the efficiency of sensory information and influence the ability of the reader to correctly interpret the mapped message. Many of the limitations on the reader's perceptual abilities appear to be organismic rather than of a cognitive nature and, therefore, may suggest absolute limitations on the ability to communicate visual information. Finally, the ...
16 citations
TL;DR: In this paper, the orthographic projection has been used for cartographic communication and it is suggested that the pocket calculator can be used to evaluate these to find sufficient co-ordinates for plotti.
Abstract: Throughout its history the principal function of cartography has been the supply of maps for navigational, engineering or cadastral purposes to a clientele interested tn the map primarily as a basis of mensuration. The interest of the map maker tended therefore to be restricted to projections whose properties facilitated accurate representation of direction, distance and area, to the neglect of other systems less well adapted to such purposes. The characteristics of the orthographic projection, formerly discounted, should now commend it for a greater role in cartographic communication especially in the space age. However, construction of the most frequently required oblique version by methods dependent on draughtsmanship, the camera or the computer may overtax either the patience or resources of the average cartographer. As an alternative, general mapping equations are derived and it is suggested that the pocket calculator can be used to evaluate these to provtde sufficient co-ordinates for plotti...
14 citations
TL;DR: In this article, the authors describe a process whereby contours may be derived directly from randomly distributed spot heights, by the use of an irregular triangular lattice of interpolation lines.
Abstract: Most techniques which derive contours from spot heights, require an intermediate procedure whereby a surface represented by an array of data points spaced on a regular grid pattern, is first fitted to groups of points before the contours are determined.This article describes a process whereby contours may be derived directly from randomly distributed spot heights, by the use of an irregular triangular lattice of interpolation lines.
11 citations
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TL;DR: A summary of land use mapping in Britain and overseas leads to a consideration of the role of the Second Lane Utilisation Survey of Britain which was established in 1960 as discussed by the authors, and additional research mapping in recent years has explored new techniques which could be applied to practical problems of urban mapping.
Abstract: A summary of land use mapping in Britain and overseas leads to a consideration of the role of the Second Lane Utilisation Survey of Britain which was established in 1960. Additional research mapping in recent years has explored new techniques which could be applied to practical problems of urban mapping.
11 citations
TL;DR: In this paper, three different selections of towns in England and Wales, at three scales (1:4 000 000, 1:8 000 000 and 1:16 000 000) are made using Topfer's Radical Law and, Moser and Scott's classification of towns.
Abstract: Three different selections of towns in England and Wales, at three scales (1:4 000 000, 1:8 000 000 and 1:16 000 000) are made using Topfer's Radical Law and, Moser and Scott's classification of towns. The results are compared with examples from atlases. Factors relevant to the selection of towns during the process of cartographic generalisation are considered.
2 citations
TL;DR: Rcaling grey-tone area symbols to compensate for visual under-estimation of data values does not address the problem of graphic stability, so graphs derived from simulation modelling can assist the map author in specifying an efficient, reduced range of grey tones so that visually indeterminate patterns are avoided.
Abstract: Rescaling grey-tone area symbols to compensate for visual under-estimation of data values does not address the problem of graphic stability Line growth is a common graphic distortion of grey tones that can occur during the photographic, plate-etching and printing stages of map reproduction A simulation model can be used to predict the effects of reproduction noise on various continuous-tone area symbols Graphs derived from simulation modelling can assist the map author in specifying an efficient, reduced range of grey tones so that visually indeterminate patterns are avoided
2 citations
2 citations
TL;DR: The authors discuss examples and suggest ways in which they may be overcome by the teacher, and discuss the importance of landscape and map studies in school geography, particularly as an introduction to the subject.
Abstract: Recent developments in academic geography have not diminished the importance of landscape and map studies in school geography, particularly as an introduction to the subject. The distinctive skills which geographers contribute to the school curriculum are those of landscape and map interpretation. Such interpretation presents the learner with conceptual difficulties, which are not always diagnosed. This paper discusses examples and suggests ways in which they may be overcome by the teacher.
TL;DR: A detailed account of the methods used in compiling a dot map of population in 1971 in the Portsmouth area, as a supplement to the Atlas of Portsmouth, is given in this article.
Abstract: The dot map is a long-established method for representing population distribution. The preparation of dot maps by both manual and computer-assisted means is examined; together with the availability of suitable Census data for the compilation of a dot map at medium scale. A more detailed account is given of the methods used in compiling a dot map of population in 1971 in the Portsmouth area, as a supplement to the Atlas of Portsmouth. Some possibilities for using the dot map as a basis for computer-drawn density maps are considered.