DESCRIBING A MAP
by
Alecia Fowler
A thesis submitted in conformity with the requirements
for the degree of Masters of Science
Graduate Department of ComputerScience
University of Toronto
©Copyright by Alecia Fowler2010
Describing a Map
Alecia Fowler
Masters of Science
Graduate Department of ComputerScience
University of Toronto
2010
Abstract
Acknowledgments (ifany)
« Use Body Text or Normal style for text in this section. »
Table of Contents
Acknowledgments (if any)
Table of Contents
List of Tables (if any)
List of Plates (if any)
List of Figures (if any)
List of Appendices (if any)
Chapter 1 Introduction
1Introduction
1.1« First level subheading uses style Heading 2 »
Chapter 2 Background
2Background
2.1Web Accessibility
2.2Web Mapping Accessibility
2.3Cartography and Visual Cognition
2.4Thematic Maps
3Approach
4Study Design and Execution
4.1Grounded Theory
4.2Previous Iterations
4.3Data Collection
4.3.1Survey
4.3.2Map Descriptions
5Results
5.1Analysis
5.2Description Results
5.3Participant Results
5.4Discussion
5.5Map Descriptions
5.6Visually Impaired Community
6Future Research
7Conclusion
References or Bibliography (if any)
Appendices (if any)
Copyright Acknowledgements (if any)
List of Tables (ifany)
List of Plates (ifany)
List of Figures (ifany)
List of Appendices (ifany)
1
1
Chapter 1
Introduction
1Introduction
1.1« First level subheading uses style Heading 2 »
Chapter 2Background
2Background
2.1Web Accessibility
Message: explain web accessibility and what it means forboth developers and users.
Accessibility refers to the extent which a tool or device can be utilized by an entire population. Web accessibility then refers to the way in which the World Wide Web and all of its content can be used by all people. Web Accessibility addresses people with all types of impediments whether it is physical, cognitive, sensory or developmental. Websites and web applications need to be designed with these impediments in mind, as well as the tools that are available to assist in the delivery of the site and applications. According to the United Nations Convention on the Rights of Persons with Disabilities and Optional Protocol @, Article 21 states it is a basic human right to have freedom of expressions and opinion, and access to information. It states the necessity of providing information intended for the general public to persons with disabilities in accessible formats and technologies appropriate to different kinds in a timely manner without additional cost. According to UN enable, they perceive the idea that a disability is not considered a medical condition, but rather a result of the interaction between negative attitudes or an unwelcoming environment with the condition of particular persons. Concluding sentence.
2.2Web Mapping Accessibility
Message: what web mapping means.
Web Mapping includes all types of maps that are placed online for use in both a static or interactive format. Sites and applications that utilize maps should follow the same guidelines made for general web content. However, maps are primarily a visual tool, and it is not yet clear how these rules should be interpreted in order to satisfy them.
Message: common research areas addressing the visually impaired and mapping
There has been an abundance of work done in the field of web mapping accessibility, in the area of navigation-based mapping and wayfinding. Since the widespread popularity of the Global Positioning System (GPS) there are now many assistive devices available to direct people with visual impairments such as the System for Wearable Audio Navigation (SWAN)@ and Talking Points@. Both are portable navigational systems that include context-awareness in order to assist people with visual impairments navigate their surroundings.
Message: how accessibility being addressed currently in popular web mapping applications
Companies such as Google have designed accessible interfaces for their web mapping applications. The interface is device independent that means all controls on the application can be accessed by multiple input devices.
Message: whataccessibility deficiencies exist in web mapping (Approach?)
Yet there is still a need for work done in accessibility that addresses the actual map image, specifically with thematic maps, where the spatial distribution is so important to the purpose of the map. This information is not provided in any other format aside from a visual image.
2.3Cartography and Visual Cognition
Message: Why maps are used to disseminate data and the theory behind how they are designed. The advantages and disadvantages of maps.
A map is a visual representation, commonly used to plot geographic data. Maps are able to convey information in a visual format that has not been achieved through the use of text, tables, or graphs. It is this implicit information that we are interested in translating into text. In order to do this, we need to understand what this information is and how it is created. The process of choosing what data will be available and how best to visually display it on a map is referred to as Cartography.
Message: the theory behind how maps are designed
When dealing with complex data from a specific space and time, mapping makes it possible to separate important factors and display them in a clear, concise manner. Cartographers rely on the process of generalization in order to design a map. This process requires them to select the relevant data from the mass of data available concerning the geographic area. The data then needs to be simplified as much as possible, while not taking any value away from the map. To further the generalization of the data it is classified and grouped. Symbolization is also used in order to apply a visual icon to the data that is easily recognized and disseminated. Each step in the process of generalization is influenced by various factors such as the purpose of the map, the scale level being used, the target audience, as well as the abilities of the cartographer.
Message: the role/influence of visual cognition in cartography
Cartography is strongly influenced by the field of visual cognition. Every step in the generalization process is tightly bound to research done in visual cognition. In cartography, the practice of projections, scale unification, and symbology has all been based on research in visual cognition. For example in relation to symbols, understanding how a person sees with their eyes variations of objects and how they convert that into mental understanding has highly influenced symbology in mapping. The human eye recognizes changes in relation to specific properties @:
Size – dimensions of an object
Value – the progression of black to white (grayscale) on an object
Texture – any pattern of marks on an object
Colour – the hue of an object
Orientation – any change to an abject without affecting its center position
Shape – the element of “similarity” associated with an object
Message: The advantages and disadvantages of maps.
Cartography draws upon research that has been done concerning these properties, and what variations of each allow for easier dissemination, as well as which properties can be paired in order to assist cognition.
2.4Thematic Maps
Message: what is a thematic map and when/why is it used.
A thematic map is a type of map that has a special purpose in order to convey a particular dataset. The intent is to understand the data in relation to the geographic area it is being overlaid upon. The dataset is layered on a base map that is more simplified than a general reference map. The advantage of thematic maps are their ability to illustrate spatial relationships.
3Approach
Message: What are the current web mapping deficiencies?
The W3C sets out standards which developers should meet in order to ensure their sites accessibility. Most checkpoints can be satisfied in a usable way for the appropriate audience when applied to web mapping applications, all except for one. According to @ every image should have a meaningful text description attached to it for the visually impaired. A map is an image that is very rich in data. There are many different maps, with varying layers of data as well as varying intents of purpose. Interactive maps on line are also changing as the user interacts with it. Each map needs a text description that is meaningful to the user but also includes an accurate description of the map. For direction-based maps, maps where the purpose is to allow a person to find a route from A to B, various solutions have been created @. (For radar maps…?) This study focuses on thematic maps specifically.
Message: What are the solutions to the above deficiencies?
In the past a popular solution to offering a text description to a thematic map has been to provide a text-based search or data tables. Thematic maps quite often have querying options in order to allow the user to find regions of interest. When returning results, instead of only showing them as visual points on a map, they also get returned in a data table. Where query options are not available, or sometimes when they are but time has not been taken for the development of a text-based search, data tables are used to dump all the data in one giant grid.
Message: How are we discerning between explicit and implicit information?
The advantage of using thematic maps is that a viewer can draw meaningful conclusions from the map through its use of spatial relationships and layout. This sort of information is not available in a text-based search. We identify Implicit Data to include:… and Explicit Data to include:….. To make a description that is comparable to the actual map image, it should take into account this implicit data.
Message: Would the visually impaired community benefit from the addition of implicit information?
Common techniques for teaching spatial relationships to the visually impaired are the use of tactile maps. @ …..
Message: What are we trying to answer in this study?
This leads us to our research question, How do sighted people (persons) describe a thematic map? When asking a sighted person to relay the information they interpret from viewing a thematic map is there a specific technique? Are there certain focal points or keywords used? How often is explicit data relied upon as opposed to implicit data? And can this help us to understand how to formulate a meaningful text description that would make a richer web-mapping experience for an accessible audience?
4Study Design and Execution
Message: what experiment design method did we follow and why
4.1Grounded Theory
The approach taken in this study is grounded theory. We wanted to generate as much data as realistically possible in order to have a database of descriptions with which to answer our research question with. Our research question is How do sighted people (persons) describe a thematic map? In order to address the lack of a map description, we wanted to find out how people who are accustomed to understanding and interpreting spatial data visually would choose to describe a thematic map. From these descriptions we hoped to be able to see differences in how explicit data as opposed to implicit data is used in the descriptions to see if they were richer than a table of search results. We also hoped to be able to create a vocabulary of commonly used words, as well as common techniques used when asked to describe a thematic map.
Message: What did we learn from testing out the study, and how we decided upon the design.
4.2Previous Iterations
We had originally designed the study to be a game much in the same way as **cite game**. We would ask participants play as partners, with one creating a description of a map, while the other one was presented with the description and the three possible maps it could represent. During paper prototypes of this study we found that participants were “gaming” their description in order to gain points and win the game quickly. We also found that they relied too heavily on the labels on the maps and used the labels as positioning devices, which did not assist in the comprehension of the map, but more so allowed them to win the game easier and quickly. This prompted us to redesign the study and take out labels on the map as well as take away the competitive aspect of the study. This may be something that can be developed once guidelines and a framework for map descriptions are available, but the game may have caused too many extra factors that were not helpful for map descriptions, but helpful in order to win the game. We instead asked the participants to describe the map as they would to another person. Each participant was given access to background information concerning the study as well as a scenario that helped explain the research problem, definitions of web accessibility, thematic maps and web mapping.
Message: What form did the study take, and how was it delivered?
4.3Data Collection
A web application was chosen as the format for this study as a way to reach as many people as possible. The web application was developed using php and html while storing data in a mysql database. The participants contacted for this study were found through the University of Toronto, Environment Canada and the forwarding from contacted parties to those interested.
4.3.1Survey
Each participant was presented with a survey which was designed to review the participant’s background, and their level of expertise in fields related to this study.
4.3.2Map Descriptions
The participants were presented with a full explanation of the terms and purpose behind the study each participant was asked to describe a map. The maps included in the study were simple thematic maps showing sample point data. The maps were from various extents and locations across Canada. The layers shown on the maps varied; some showing landmarks and some without. The maps displayed were chosen from a group randomly. The participants had the option of describing the same map three times in case they wanted to take different approaches in their descriptions. The participants were asked to describe three different maps before they were thanked for their participation in the study and given the option of ending the study or continuing and describing three more maps.
The maps varied in extent level as well as symbology. We wanted to test against these factors, and find if they affected participant’s descriptions.
5Results
Message: How was the data disseminated and classified?
5.1Analysis
The data was cleaned and descriptions were then coded according to pre-defined classifications, keywords were found and grouped into their appropriate categories. There were some overlaps and similarities between categories. Once the keywords were tagged the context used for the keywords were analyzed in order to identify techniques used for describing a map.
Format? Location? Add descriptions/explanations for each category:
The following categories and sub-categories were used to code the descriptions:
- Direction
- Cardinal
- Placement
- Movement
- Division
- Geometric
- Topography
- Water Body
- Land Mass
- Thoroughfare
- Broad
- Quantitative
- Rank
- Grouping
- Unit
- Division
- Shapes
- Literal: circle, square, diamond etc.
- Implied: jagged, smile-shaped, meandering etc.
- Landmarks
- Airports, parks, ferries etc
- Query Data
- Facilities Reporting Pollutant Releases, 2008, Substances etc.
- Thematic
- General: points, dot etc.
- Specific: polluting sites, facilities etc.
- Size
- Small, large, tiny etc.
- Jurisdiction
- Extent: province, city, town, etc.
- Community: neighbourhood, industrial, residential etc.
- Colour
- Blue, orange etc.
- Distance
- Km, cm, inch etc
- Location (Specific)
- Montreal, St. John, Charlottetown etc.
5.2Description Results
Message: What general techniques were followed when formulating a description?
The most common technique used when describing a map is to refer to “North”, “South”, “East” and “West” to situate the description of the thematic data
This is then followed by the second most common technique, referring to the base map, many people will choose a body of water (river, lake, etc.) or a road/street first, to give their description context
There were also two noticeably dominant techniques when describing the map. To choose a specific target (i.e. river, lake, city center) and then describe everything on the map in relation to the target. If there was no obvious target available, participants chose to divide up the map (into quadrants, top-down, left-right) and progressively describe the maps in smaller pieces.
Message: What were the trends when utilizing explicit vs. implicit information?
Statistics of technique usage
Implicit vs. Explicit Data:
Implicit data refers to parts of the description that has at this point in time, only been available though viewing the thematic map. Whereas explicit data: to refer to parts of the description that could easily become available through a text-based search.
Of the categories, three use predominantly implicit data (Direction, Geography, and Shapes) and exist within the top 4 rankings, while the rest are explicit (Quantitative, Landmarks, Query Data, and Thematic).
Message: What effect did extent level have on the descriptions?
The Effect of Extent Level:
When describing a rural setting (an area where there is not a lot of variety to the map design) a person will focus on a landmark (airport, park, etc.) in order to give their description some context
When describing an urban setting the last five categories seem less crucial, this could be because there is already many features in an urban map in order to give a description context. In a rural setting, there is less variety and people are forced to reach and get creative.
Message: How was context taken into account in the analysis?
Context:
When reviewing the context of the keywords and categories, we took the top 5 occurring keywords from each category and viewed them within the context of their descriptions
Table?
- Direction
- north
- south
- east
- west
- bottom
- Topography
- river
- water
- lake
- road
- ports
- Landmarks
- airport
- park
- airplane
- symbols
- rail
- Quantitative
- third
- second
- number
- Query
- pollutant
- facilities
- release
- Canada
- Shapes
- cluster
- long
- tree
- scattered
- concentration/ed
- Thematic
- points
- facilities
- dots
- sites
- diamonds
- Size
- Jurisdiction
- Colour
- Distance
- Location
5.3Participant Results
Message: What effect did the participants backgrounds have on the map descriptions?