Chart Types and their Uses
Overview of Chart Types and their Uses  Area
Chart  Column/Bar Chart  Segmented
Column/Bar Chart  Frequency Polygon and Histograms  Line
Chart  Pie Chart  Scatterplot
Overview of Chart Types and their Uses
Chart Type 
PIG 
Typical Applications 
Variants, Remarks 
Area 
Yes 
Cumulated totals (numbers or percentages)
over time 
Percentage, Cumulative 
Column/Bar 
Yes 
Observations over time or under different
conditions; data sets must be small 
Vertical (columns), horizontal (bars);
multiple columns/bars, columns/bars centered at zero 
Segmented Column/Bar 
Yes 
Proportional relationships over time 
May be scaled to 100% 
Frequency Polygon 
No 
Discrete frequency distribution 

Histogram 
No 
Discrete frequency distribution 
Columns/bars without gaps 
Line, Curve 
Yes 
Trends, functional relations 
Data point connected by lines or higher
order curves 
Pie 
Yes 
Proportional relationships at a point
in time 
Segments may be pulled out of the the
pie for emphasis (exploded pie chart) 
Scatterplot 
No 
Distribution of data points along one
or two dimensions 
Onedimensional, twodimensional 
Map 
No 
Typically used for geographical data;
can also be used for parts of devices, human or animal bodies 
Useful, if an analog relation can be used
for representing data 
The column PIG indicates whether the respective charts types are available
as Portable Interactive Graphics.
Area Chart
Figure 1: Area chart
Use it to...
 Display over time (or any other dimension):
 How a set of data adds up to a whole (cumulated totals)
 Which part of the whole each element represents
Variants
 Percentage: The sum always represents 100% (relative scale)
 Cumulative: The sum can vary according to the elements (absolute
scale)
Column/Bar Chart
Use it to...
 Present few data over a nominal (e.g. countries, testing conditions, ...)
or interval scale (e.g. time); useful for comparisons of data
Do not Use it for...
 Comparisons: Better use onedimensional scatterplots, because these are
not dominated by bars or columns.
 Larger data sets: Use line charts.
Selecting Bars or Columns
 Use analogy as a selection criterion, if applicable; when in doubt, use
columns
 Use a horizontal bar chart if the labels are too long to fit under the
columns
Variants
 Multiple Column/Bar Chart: Use it to present data rows for several
variables
 SidebySide Chart: Use it to (1) show contrasting trends between
levels of an independent variable, (2) if comparisons between individual
pairs of values are most important; do not use for more than two independent
variables
Figure 2: Multiple column chart (left), sidebyside
chart (right)
Segmented Column/Bar Chart
Other Names: Divided or stacked column/bar chart
Figure 3: Segmented column chart (relative values)
Use it to...
 Present a partwhole relation over time (with accurate impression, see
below)
 Show proportional relationships over time
 Display wholes which are levels on a nominal scale
Segmented column/bar charts are more accurate than pie chart, because distances
can be more accurately estimated than areas.
Frequency Polygon, Histograms
Figure 4: Histogram as frequency distribution
Variants
 Polygon: Connects data points through straight lines or higher order
graphs
 Histogram: Columns/bars touch; useful for larger sets of data points,
typically used for frequency distributions
 Staircase Chart: Displays only the silhouette of the histogram;
useful for even larger sets of data points, typically used for frequency
distributions
 Step chart: Use it to illustrate trends among more than two members
of nominal or ordinal scales; do not use it for two or more variables
or levels of a single variable (hard to read)
 Pyramid histogram: Two mirror histograms; use it for comparisons
Line Chart
Figure 5: Line chart
Use it...
 To display long data rows
 To interpolate between data points
 To extrapolate beyond known data values (forecast)
 To compare different graphs
 To find and compare trends (changes over time)
 To recognize correlations and covariations between variables
 If the X axis requires an interval scale
 To display interactions over two levels on the X axis
 When convention defines meaningful patterns (e.g. a zigzag line)
Line graphs may consist of line or curved segments:
 Lines: Use straight lines to connect "real" data points
 Curves: Use curves to represent functional relations between data points
or to interpolate data
Do not Use it...
 If the X axis has nonnumeric values
Variants
 Graph with doublelogarithmic or halflogarithmic scale divisions
 Graph with variance bars, stock charts (High/Low/Close) etc.
Pie Chart
Figure 6: Pie chart
Use it to...
 convey approximate proportional relationships (relative amounts) at a point
in time
 compare part of a whole at a given point in time
 Exploded: emphasize a small proportion of parts
Do not Use it ...
 For exact comparisons of values, because estimating angles is difficult
for people.
 For rank data: Use column/bar charts in this case; use multiple column/bar
charts for grouped data
 If proportions vary greatly; do not use multiple pies to compare corresponding
parts.
Caution!
 Pie charts cannot represent values beyond 100%.
 Each pie chart is valid for one point in time only.
 Pie charts are only suited to presenting quite a few percentage values.
 Angles are harder to estimate for people than distances; perspective pie
charts are even harder to interpret.
Scatterplot
Figure 7: Onedimensional scatterplot (left), twodimensional
scatterplot (right)
Variants
 Onedimensional scatterplot: Data point are drawn above a baseline
(as in column/bar charts). Here the data points are not connected but remain
isolated data points.
 Twodimensional scatter plot: Shows correlation between two data
sets. This chart type has two dependent variables: One is plotted along the
X axis, the other along the Y axis; the independent variable is the intersection
of both dependent variables, realized as a data point in the diagram.
Use it to...
 Show measurements over time (onedimensional scatterplot)
 Convey an overall impression of the relation between two variables (Twodimensional
scatterplot)
Do not Use it for...
 Determining and comparing trends, interpolation, extrapolation, recognition
and comparison of change rates
 More than one independent variable: Avoid illustrating more than one independent
variable in a scatter plot
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Source: Recommendations
for Charts and Graphics
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