divides the range of attribute values into equal sized sub ranges, allowing one to
specify the number of intervals while the algorithm determines where the breaks
should beequal interval
emphasizes the amount of an attribute value relative to other values
equal interval
best applied to familiar data ranges such as percentages and temperature
equal interval
GOOD: presenting information to a non-technical audience
easier to interpret especially for familiar values like percentages
equal interval
DISADVANTAGE: values may cluster in the histogram, may have many
features in one class and none in anotherequal interval
each class contains an equal number of features
quantile
well suited to linearly (i.e. evenly) distributed data
quantile
similar features can be placed in adjacent classes, or features with widely different
values can be put in the same classquantile
distortion can be minimized by increasing the number of classes
quantile
GOOD: emphasizing relative position (e.g. which countries are in the top 20% for
income)quantile
DISADVANTAGE: features with similar values may end up in different classes,
exaggerating their Differences reverse can also happen: wide range of values can end
up in the same classes, minimizing differencesquantile
classes are based on natural groupings inherent in the datanatural breaks
identifies break points by picking the class breaks that best group similar values and
maximizes differences between classesnatural breaks
boundaries are set where there are relatively big jumps in the data values
natural breaks
GOOD: mapping values that are not evenly distributed in the histogramnatural breaks
DISADVANTAGE: class ranges are tailored to one data set, so difficult to compare maps
can be difficult to choose optimum number of classes especially if data are
evenly distributednatural breaks
creates class breaks based on class intervals that have geometric seriesgeometric int
the algorithm minimizes the sum of squares of the number of elements in each class
geometric int
ensures that each class range has approximately the same number of values with each
class and the change between intervals is fairly consistentgeometric int
GOOD: designed to accommodate continuous data creates a balance between
highlighting changes in the middle values and the extreme values, thereby visually
appealing and cartographically comprehensivegeometric int
DISADVANTAGE: especially if data are evenly distributedgeometric int
shows how much a feature’s attribute value varies from the mean
standard dev
class breaks are created based on the calculated mean and the standard deviations
from the mean
standard dev
two-color ramp helps emphasize values above (shown in blue) and below (shown in red)
the meanstandard dev
GOOD: seeing which features are above or below an average value data has a normal
distributionstandard dev
DISADVANTAGE: map doesn’t show actual values, only how far values are from the
mean very high or low values can skew the meanstandard dev
divides the range of attribute values into equal sized sub ranges, allowing one to
specify the number of intervals while the algorithm determines where the breaks
should beequal interval
emphasizes the amount of an attribute value relative to other values
equal interval
best applied to familiar data ranges such as percentages and temperature
equal interval
GOOD: presenting information to a non-technical audience
easier to interpret especially for familiar values like percentages
equal interval
DISADVANTAGE: values may cluster in the histogram, may have many
features in one class and none in anotherequal interval
each class contains an equal number of features
quantile
well suited to linearly (i.e. evenly) distributed data
quantile
similar features can be placed in adjacent classes, or features with widely different
values can be put in the same classquantile
distortion can be minimized by increasing the number of classes
quantile
GOOD: emphasizing relative position (e.g. which countries are in the top 20% for
income)quantile
DISADVANTAGE: features with similar values may end up in different classes,
exaggerating their Differences reverse can also happen: wide range of values can end
up in the same classes, minimizing differencesquantile
classes are based on natural groupings inherent in the datanatural breaks
identifies break points by picking the class breaks that best group similar values and
maximizes differences between classesnatural breaks
boundaries are set where there are relatively big jumps in the data values
natural breaks
GOOD: mapping values that are not evenly distributed in the histogramnatural breaks
DISADVANTAGE: class ranges are tailored to one data set, so difficult to compare maps
can be difficult to choose optimum number of classes especially if data are
evenly distributednatural breaks
creates class breaks based on class intervals that have geometric seriesgeometric int
the algorithm minimizes the sum of squares of the number of elements in each class
geometric int
ensures that each class range has approximately the same number of values with each
class and the change between intervals is fairly consistentgeometric int
GOOD: designed to accommodate continuous data creates a balance between
highlighting changes in the middle values and the extreme values, thereby visually
appealing and cartographically comprehensivegeometric int
DISADVANTAGE: especially if data are evenly distributedgeometric int
shows how much a feature’s attribute value varies from the mean
standard dev
class breaks are created based on the calculated mean and the standard deviations
from the mean
standard dev
two-color ramp helps emphasize values above (shown in blue) and below (shown in red)
the meanstandard dev
GOOD: seeing which features are above or below an average value data has a normal
distributionstandard dev
DISADVANTAGE: map doesn’t show actual values, only how far values are from the
mean very high or low values can skew the meanstandard dev