Introducing Thematic Maps in the Primary Grades

Karen M. Trifonoff
When it comes to mapping activities for the early elementary grades, teachers often rely on the materials provided in workbooks accompanying the text. Most of these are very simple exercises dealing with navigation and way-finding. However, there is research indicating that children can understand and learn from much more sophisticated map presentations. This article introduces some recent research on mapping in the primary grades, and suggests alternatives to the typical location map exercises that will better challenge a child's expanding sense of space.
Maps are used in many forms by young children. Creating mental, or cognitive, maps is a natural ability and children carry around many cartographic images that reflect their experiences with the environment. Mapping behaviors are exhibited by children in such play activities as constructing roads in sand or creating neighborhoods with blocks and navigating through these settings. Such behaviors occur before the teaching of formal map skills.

It seems logical, then, that the first maps encountered in school should build on these early childhood experiences involving navigation and wayfinding. These maps typically show local areas and contain such landmarks as a school, parks, and homes: students have to identify specific features or navigate from one place to another. Most research on children and mapping focuses on these navigation and wayfinding maps, and all report very positive findings: children have the ability to understand and work with navigation maps.

But why should research stop with these mapping skills? If children exhibit good spatial skills in navigation and wayfinding, they may be able to work equally well with other types of maps. The reason that navigation maps are used almost exclusively is because many early geographic educators believed children to have a poorly-developed sense of space. Most modern studies suggest the opposite. Students do have well developed spatial understanding and they continue to astound researchers with their advanced mapping behaviors.1 Forsythe summarizes much of the modern research in his annotated bibliography, Learning Geography: An Annotated Bibliography of Research Paths.2

Geographic Education and Mapping
The research supporting children's advanced spatial abilities is particularly relevant in light of geography's changing role in the classroom. In geographic education today, the focus is on expanding the view of geography from a location and place name discipline to one that emphasizes a more holistic view of the physical and cultural elements of our planet. The Guidelines for Geographic Education outline five fundamental themes of geography: location, place, relations within places, movement, and regions.3 These themes involve all geographic concepts, but emphasize detailed information about maps and mapping skills. As stated: "Reading, interpreting and making maps are skills integral to geographic education and to acquiring geographic knowledge."4
Another recent publication that has changed geographic education is Geography for Life: National Geography Standards.5 It establishes benchmarks to aid in the selection of themes and topics suitable for each grade level. In order to implement the standards and meet the goals of the five themes effectively, map use in the primary grades should go beyond simple location maps to include maps that are more appropriate to students' spatial abilities.

One type of map that is ideal for exploring all five themes of geography is the thematic, or special purpose, map. A thematic map illustrates a single idea, distribution, or relationship. Thematic maps start with a base map (for example, a blank outline map of the United States), and add to it the data layer, or special information, to be portrayed. This data layer can take two forms: qualitative or quantitative.

Qualitative data is categorical information and does not involve the use of numbers. An example of a qualitative thematic map is shown in Figure 1, Landforms of the United States. It uses colors (abstract or pictorial symbols would also be possible) to illustrate four categories of landforms: mountains, highlands, plateaus, and plains.

A second type of thematic map is quantitative, meaning that it illustrates numerical data. A quantitative thematic map (designed for use in an experiment described later in this article) is shown in Figure 2, Trees Climbed During the Summer. It uses a gray scale, with tones moving from light to dark, to distinguish different numbers of trees climbed.

Thematic maps pose a strong contrast to the general location maps typically found in elementary texts (see Figure 3); these have been called "contrived maps" because of the artificial way they look at the world.6 A comparison of the trees climbed map and the general location map reveals important differences in levels of graphic design and intellectual complexity. The location map can be categorized as simple at both levels; the information students are asked to obtain from it requires no more than basic location and matching skills. The trees climbed map has a more complex design, causing the intellectual tasks to change somewhat. Its use of a gray scale allows students to link changes in tone to the map key and the values it represents. In general, the level of graphic complexity in a map leads to more intellectually challenging questions that demand children use critical thinking skills.7

The key to using thematic maps effectively involves the kind of data included. This information can come from any source or subject area, making thematic map activities ideal for integration with other disciplines. For example, the historical sequence of settlement in a region could be shown with a series of dot maps illustrating the growth of population over time. Movement or increased traffic flows could be illustrated with flow line maps.

Environmental topics are explored in science classes at all grade levels, and maps can be an effective tool in illustrating scientific issues. One of the benchmarks for fourth graders in the National Geography Standards is to "cite specific examples from anywhere in the world to illustrate environmental issues (e.g., deforestation and air and water pollution)."8 Take the issue of coal mining and its various environmental impacts. These could be shown with thematic maps of, for example, (1) the amount of coal removed from a mine or mine region in a specific period of time, (2) the number of people employed (including young children in some places on the globe), and (3) changes to the landscape, such as the alteration of topography and vegetation, as a result of mining activity. "How much of what is where" can also be determined by using thematic maps. As Mosenthal and Kirsch note, "Despite the frequency and importance of thematic maps in our lives, relatively little attention has been given to these maps from an instructional standpoint."9

An Experiment
The following describes an experiment we designed to evaluate the ability of first grade students to interpret thematic maps. The subjects were 14 students in the first grade (Table 1). The experiment began with a group instruction session that introduced several concepts used in thematic mapping, from the making of a base map to the addition of data, a legend, and a color scheme. This phase also allowed students to become familiar with the instructor and the computer format of the experiment.
In the second phase, students were tested individually on their ability to interpret eight different thematic maps of the United States (Table 2). In order to generate maps of interest to this age group, several first graders not involved in the experiment were asked for lists of things they liked or found interesting. Hypothetical data sets with either four or five classes were generated for these eight topics. The thematic maps had either clustered or random distributions. The clustered distributions had concentrations of high or low values in certain areas (Figure 4, Visitors to Disney Amusement Parks), while the random distributions had the values spread more evenly across the map (Figure 5, Hours Spent Playing Sega).

Two types of questions were used to evaluate student reactions to these maps. The first required students to select or click on the correct answer on a computer screen. For these questions, accuracy and reaction time were recorded. A typical question, this one based on the Sega map, was: "Click on a state where two to three hours are spent playing Sega." The second type of question was open-ended and required students to talk about the map. A typical question was, "Describe where the high and low values are located on this map."

Students responded favorably to both types of questions. Accuracies were high, indicating that students could match the legend colors or tones to those on the map. The maps that called for students to choose between two states had higher accuracies and faster times than those requiring a search of the entire map (Table 3).

The purpose of the open-ended questions was to determine whether students could understand geographic distributions and assign meaning to them. At first, the students who were unfamiliar with this type of question exhibited hesitancy in discussing the maps. But, after the first or second map, they grew more comfortable with the questions, and more able to respond to the spatial pattern on a map with some insight.

For example, for the map showing trees climbed during the summer, students were asked simply to describe the map. Answers such as, "The colors are switched around from the last map," "It's higher because it is a darker color," "Not much dark colors out here (west)," and "Colors are all scattered around," indicated that students understood the legend, including its use of the color scheme and what the values represented. Students could explain where the high and low values were located, point out the degree of clustering and dispersion of the phenomena, and even hypothesize as to reasons for the geographic distributions. These responses indicated that they understood the level of abstraction and the idea that the variable displayed on the map represented the characteristics of first grade students in the state (for sample responses to two other maps, see Table 4).

Thematic Map Exercise
Based on the success of this experiment, we developed a lesson to introduce students in the primary grades (one to three) to thematic maps. The following outline summarizes the steps in this thematic mapping lesson. While local scale is used in this example, regional or national scales would also be appropriate. First graders are comfortable with the national map, an image they see on television, in games, and while traveling. Young children also develop a national perspective (the idea of a nation called the United States) from indirect classroom activities such as reciting the Pledge of Allegiance.10
The lesson on thematic mapping is built around group discussion and interaction. The teacher uses each graphic to initiate the discussion and to lead on to the next graphic. After the instruction portion, the students can work individually or in groups on making their own thematic maps.

Steps in a Thematic Mapping Activity
1. Base Map

The activity begins with the use of a Base Map of a Neighborhood (Figure 6) to replace the type of contrived map shown in Figure 3. While the base map itself is over-simplified, it provides a model for introducing children to the concepts involved in thematic mapping.

2. Data Table
The next step is to introduce a thematic variable with a data table. The hypothetical data set used here is quantitative and involves the number of pets in households (Table 5).

A qualitative data set might be the types of pets in households.

3. Base Map and Data
The teacher now introduces the idea of the thematic map layer by placing the data on pets on the base map (Figure 7). The placing of these numbers on the map is an intermediate step that precedes the adoption of some color or symbol to make the geographic distribution stand out.11 Ask students if they can think of any other way to portray this data as a lead-in to creating a map legend.

4. Map Key or Legend
Creating the map key, or legend, is an essential step involving decisions about symbolization and classification that novice mapmakers may overlook. The two processes are related, and can be dealt with together or apart. A standard cartographic textbook will provide background in symbolization and classification.12

Symbolization involves the color or symbol used to represent the data. Student suggestions for quantitative variables may include such ideas as: "change the size of the house" or "change the color of the house." It is standard cartographic convention when showing numerical information to go from light to dark tones of one color (hue) to show the low to high values. For a qualitative variable, where no numbers are involved and names are the categories (e.g., types of pet), it is best to use a change of color to indicate these differences.

Classification involves putting the data into groups. Younger students may require a simple classification scheme, with "low," "medium," and "high" making up the groups or classes. Another option is to have each class represent only one number. As math skills improve, a data range can be used for each class, such as: 1-5, 6-10, 11-15. It is important to note that the data ranges for each class should be mutually exclusive. For example, if the first class goes from 1-5, the second should start with the number 6. If 5 is repeated, it suggests that the number 5 could be in two classes, leading to confusion among students of any age.

The proper number of classes for children this age has not been established, although our experiment showed no significant difference in accuracy of responses between maps with four and five classes. A previous experiment found nearly perfect accuracies for second graders with an ordinal classification scheme of low, medium, and high; a recommendation of this research was to expand the number of classes to four or five and to use the actual numerical values as data.13 Another cartographic convention suggests a maximum of five to seven classes for adult map users in order to allow for proper response to the color or tones.

The final step here is to put symbols and data classes together in the map key. Figure 8 contains three alternative legends for mapping the number of pets in households.

5. Final Thematic Map
Add the legend to the base map with data, and use this final thematic map (Figure 9) to generate questions. The map legend is the guide to their answers. Some potential questions for this activity are: "Find a house with two pets" or "How many houses do not have any pets?" Open-ended questions might include: "Describe the location of pets on this map" or "Where do the people without pets live? What might explain this?"

Encourage discussion questions that deal with more than just location and that link the five themes of geography to help students discover "why things are where they are." For example, having a pet in the household might vary with living in rental vs owner-occupied property. Or, it might vary with the age of residents in more than one way. Maybe the number of pets is related to the number of children, either in direct or inverse proportions.

6. Option: Students Collect Data
This series of steps can be used for the instruction phase of the lesson on thematic mapping. Students could then move on to working with actual maps of their neighborhood and other data sets that interest them and for which they can collect information. For example, they might count the number of trees in front yards (quantitative) or types of trees (qualitative). Or, they might count the number of trash bags (quantitative) or the types of recycling exhibited by households (qualitative). Students could work individually or in groups and present their finished maps to the whole class for discussion.

The change from location to thematic maps will not occur overnight, and there will be periods of trial and error as educators search for the right combination of maps to present to primary students. Classroom teachers need to provide geographers and cartographers with feedback on what works best. When geographers and cartographers work with elementary teachers, more effective mapping activities can be developed. By improving the mapping abilities of primary students, we have a greater chance of seeing that improvement continue through all the school years and into adulthood-so helping to create a more map-literate society.

1. J.M. Blaut, "Natural Mapping," Transactions of the Institute of British Geographers 16 (1991): 55.
2. Alfred S. Forsythe, Jr., Learning Geography: An Annotated Bibliography of Research Paths, Pathways in Geography Series Title No. 11 (Indiana, PA: National Council for Geographic Education, 1995).
3. Joint Committee on Geographic Education, Guidelines for Geographic Education: Elementary and Secondary Schools (Washington, DC: National Council for Geographic Education and Association of American Geographers, 1984).
4. Ibid., 2.
5. Geographic Education Standards Project, Geography for Life: National Geography Standards (Washington, DC: National Geographic Society, 1994).
6. Joan Maier, "Map Reading Across the Curriculum: Linking Geography to Children's and Adolescent Literature" (Paper presented at NACIS XVI, North American Cartographic Information Society, 2-5 October 1996).
7. Henry W. Castner, Seeking New Horizons. A Perceptual Approach to Geographic Education (Montreal and Kingston: McGill-Queen's University Press, 1990), 12-24.
8. Geographic Education Standards Project, 239.
9. P. B. Mosenthal and I.B. Kirsch, "Understanding Thematic Maps," Journal of Reading 34 (1990): 136.
10. Yi-Fu Tuan, Space and Place: The Perspective of Experience (Minneapolis: The University of Minnesota Press, 1977).
11. Borden D. Dent, Cartography: Thematic Map Design, 4th ed. (Dubuque, IA: William C. Brown Publishers, 1996), 122-151.
12. Ibid.; Arthur H. Robinson, et al, Elements of Cartography, Sixth Edition (New York: John Wiley and Sons, Inc., 1995).
13. Karen M. Trifonoff, "Going Beyond Location: Thematic Maps in the Early Elementary Grades," Journal of Geography 94 (1995): 370.

Special thanks to Ms. Amy Willever for her assistance in generating the maps and data sets, and to Mrs. Kathy Lorelli and her first grade class at Beaver Main Elementary School in Bloomsburg, Pennsylvania, for their assistance in the map experiment.

About the Author
Karen M. Trifonoff is an associate professor in the Department of Geography and Earth Science, Bloomsburg University, Bloomsburg, Pennsylvania.