Graphical skills

7.1 Cartographic skills

Graphical skills

  1. Data representation

    1. A scattergraph shows the relationship between two variables using a sample of data points
    2. A line graph shows the relationship between two continuous variables as they change using data points connected with line segments
    3. A histogram shows the distribution of data using samples that are grouped into bars of proportional area
    4. A bar chart compares a categorical variable by using proportional-length bars that can be horizontal or vertical
    5. A grouped bar chart presents bars in groups according to different criteria
    6. A stacked bar chart divides bars into parts to show a cumulative effect
    7. A pie diagram is a circular chart that is divided into segments that show the proportion of the whole each part takes up
    8. A ternary graph shows the ratio of three variable that sum to a constant by a point in an equilateral triangle
  2. Data concepts

    1. A line of best fit is the line that most closely follows a sample of data
    2. An anomaly is a data point that does not follow the pattern established by the rest of the data set
  3. Thematic maps

    1. A thematic map is one designed to show a particular theme connected with a specific geographical area
    2. A choropleth map compares areas using colour: typically, differences in hue denote qualitative differences and differences in saturation or lightness denote quantitative differences
    3. An isoline map shows the variation of a continuous quantity over an area using contour lines
    4. A dot map plots occurrences of a phenomenon to show the variation in frequency over an area
    5. A proportional symbol map compares areas using symbols of proportional sizes
    6. A desire line map shows the movement of a population between points in an area using lines whose thickness is proportional to the frequency of movement
    7. A flow line map shows the route of movement of a population in an area using lines whose thickness is proportional to the frequency of movement
    8. A topological diagram preserves the connections between points on a map but not the shape, like the London Underground map