Czytelność kartogramów prostych i złożonych - badania eksperymentalne

• Autorzy: Leonowicz A.

Warianty tytułu

EN

Effectiveness of one-variable and two-variable choropleth maps - an experimental research

• Języki publikacji: PL

Abstrakty

PL

W artykule omówiony został eksperyment przeprowadzony z udziałem użytkowników map, którego celem było porównanie kartogramów prostych i złożonych pod względem czytelności informacji o rozmieszczeniu zjawisk oraz informacji o zależności zjawisk. Uzyskane wyniki świadczą o tym, że kartogramy złożone są dobrze czytelną formą prezentacji zależności zjawisk, co weryfikuje dotychczasowe poglądy kartografów.

EN

Two-variable choropleth method allows to present two different quantitative variables on the same map. The purpose of such mapping technique is to visualize geographic relationship. Readers' perception is considered to be an important limitation of two-variable choropleth maps. The negative opinion about the effectiveness of this form of presentation is based on maps published in the 1970s by the U. S. Bureau of the Census. Poor readability of Census maps results from an inappropriate graphic representation and it was evidenced experimentally (J. Olson 1981). In order to check improperly designed two-variable chorpleth maps can be well understood by their readers, an experimental test was conducted, in which the effectiveness of one-variable and two-variable solution was compared. It was checked if one-variable maps are more appropriate to show spatial distribution and if two-variable maps make the geographic relationship easier to interpret. The participants were 128 students of geography at Warsaw University. They performed different typical map-reading tasks on one-variable and two-variable choropleth maps. The students were divided into two groups. Each student performed the test twice, each time using a different type of maps - the first group worked with one-variable maps first, the second group worked with two-variable maps first. In order to design comprehensive two-variable maps a complementary color scheme, proposed by J.R. Eyton (1984), was used and number of classes was limited to 9 (3x3). The maps created for experiment looked like the actual census maps. The test consisted of six tasks. The students were asked to extract from maps information about distributions (tasks Rp1, Rp2, Rp3) and variables relationship (tasks Zp1, Zp2, Zp3). Questions were asked about specific as well as about general information; they referred to individual enumeration units, regions and whole maps. As a test result the percentage of correct responses was calculated. At the end of the experiment students expressed their opinions and preferences about both types of maps. The results of this experiment verify opinion about poor readability of two-variable choropleth maps. Students were more accurate in reading spatial distribution on one-variable maps (especially the general pattern) and in reading spatial relationship (at every level of perception) on two-variable maps. They found two-variable maps a little bit more difficult to interpret but this form of presentation seemed more unusual and interesting. They found also that one-variable solution is more appropriate to read distribution and two-variable solution - to read variables relationship. These results showed that two-variable maps, if properly designed, can be quite properly interpreted by map readers and can be useful in visual exploration of geographical data, especially when the relationship between phenomena is crucial.

Słowa kluczowe

PL

kartogram prosty; kartogram złożony; czytanie mapy; mapa; czytelność; zależność zjawisk geograficznych

EN

one-variable choropleth map; two--variable choropleth map; map reading; geographical relationship; effectiveness

• Wydawca: Polskie Towarzystwo Geograficzne. Oddział Kartograficzny
• Czasopismo: Polski Przegląd Kartograficzny
• Rocznik: 2006
• Tom: T. 38, nr 1
• Strony: 5--23
• Opis fizyczny: Bibliogr. 20 poz., rys., tab.

Twórcy

autor

Leonowicz A.

• Instytut Geografii i Przestrzennego Zagospodarowania PAN, Warszawa

Bibliografia

• Bertin J.,1967,Semiologie graphique:les diagrammes,les reseaux, les cartes. Paris: Gauthier-Villars.
• Boczarow M.K., 1966, Osnowy tieorii projektirowanija sistiem kartograficzeskich znakow. Moskwa: Izdatielstwo Niedra.
• Bonin S., 1989, Poziomy czytania mapy. ,,Polski Przegl. Kartogr." T. 21, nr 2, s. 49-62.
• Brewer C.A., 1994, Color use guidelines for mapping and visualization. W: A.M. MacEachren, D.R.F. Taylor (red.), Visualization in modern cartography, s. 123-147, Oxford: Elsevier.
• Brewer C.A., MacEachren A.M., Pickle L.W., Hermann D., 1997, Mapping mortality: evaluating color schemes for choropleth maps. ,,Annals of the Assoc. of American Geographers" Vol. 87, no. 3, s. 411-38.
• Brewer C.A., Hatchard G.W., Narrower MA, 2003, Color Brewer in print: a catalog of color schemes for maps. Cartography and Geogr. Inform. Science" Vol. 30, no. 1, s. 5-32.
• Brzeziński J., 2002, Metodologia badań psychologicznych. Warszawa: Wydawn. Naukowe PWN.
• Carstensen L.W., 1982, A continuous shading scheme for two-variable mapping. ,,Cartographica" Vol.19, no. 3/4, s. 53-70.
• Carstensen L.W., 1984, Perception of variable similaritvon bivariate choropleth maps. ,,Cartogr. J." Vol. 21, no. 1, s. 23-29.
• Carstensen L.W., 1986, Hypothesis testing using univariate and bivariate choropleth maps. ,,The American Cartographer" Vol.13, no. 3, s. 231-251.
• Eyton J.R., 1984, Complementary-color, two-variable maps. ,,Annals of the Assoc. of American Geographers" Vol. 74, no. 3, s. 477^490.
• Garmiz I.W., 1990 Kaczestwo kart. Leningrad: Izdat.Leningradskogo Uniwiersitieta.
• Leonowicz A., 2002 a, Z problematyki porównywalności kartogramów ,,Polski Przegl. Kartogr." T. 34, 2002, nr 1, s. 22-33.
• Leonowicz A., 2002 b, Prezentacja zależności zjawisk metody kartogramu złożonego. ,,Polski Przegl. Kartogr." T. 34, nr 4, s. 273-285.
• Mersey J.E., 1990, Colour and thematic map design: the role of colour scheme and map complexity in choropleth map communication. ,,Cartographica" Vol. 27, no. 3, s. 1-157.
• Olson J., 1975, The organization of color on two-variable maps. W: Proceedings of the International Symposium on Computer-assisted Cartography, Auto-Carto II, s. 289-294.
• Olson J., 1981, Spectrally encoded two-variable maps. Annals of the Assoc. of American Geographers" Vol. 71, no. 2,3.259-276.
• Robinson A.M., Sale R.D., Morrison J.L., 1988, Podstawy kartografii. Warszawa: PWN.
• Sulek A., 1979, Eksperyment w badaniach społecznych. Warszawa: PWN.
• Weiner H., Francolini C.M., 1980, An empirical inquiry concerning human understanding of two-variable map. ,,The American Statistician" Vol. 34, no. 2, s. 81-93.