Page 77 - DCOM203_DMGT204_QUANTITATIVE_TECHNIQUES_I

Quantitative Techniques – I

Notes 4.5 Summary

The diagrammatic presentation of data provides a quick and an easier way to understand
the broad nature and trends of the given data.

Diagrams are capable of being understood easily even by a common man. In addition to
this, they facilitate the process of comparison of data in two or more situations.
While using diagrams, their limitations must always be kept in mind.

Diagrams give only a vague idea of the problem and therefore, cannot be used as a
substitute for classification and tabulation.
The diagrams can portray only a limited number of characteristics and are no longer
useful when the number of characteristics become large.
The main limitation of the diagrams being that these cannot be used as a tool of analysis.
Various types of diagrams can be divided into five broad categories, viz. one-dimensional,
two-dimensional, three-dimensional, pictograms and cartograms.
Some important one-dimensional diagrams are line diagram, bar diagram, multiple bar
diagram, component bar diagram, etc.
Rectangular, square and circular diagrams are examples of two-dimensional diagrams.
Cubes sphere and cylinder, etc., are three-dimensional diagrams.
The diagrams can also be constructed by using relevant pictures or maps.

4.6 Keywords

Bar diagrams: One-dimensional diagrams are also known as bar diagrams.
Broken-Scale Bar Diagram: When there are one or more figures of unusually high magnitude
while the majority of the figures are of low magnitude, the diagrammatic representation is done
by using a broken scale.
Cartograms: Cartograms are used to represent data relating to a particular country or to a
geographical area. Such a diagram can be used to represent various types of characteristics like
density of population, yield of a crop, amount of rainfall, etc.

Deviation Bar Diagram: This diagram represents net quantities like profit and loss, positive and
negative balance of trade, surplus and deficit, etc. Positive quantities are shown above X-axis
and negative quantities are shown below it.

Duo-Directional Bar Diagram: This diagram is used to show an aggregate of two components.
One of the components is shown above X-axis and the other below it. Both the components
added together give total value.
Line Diagram: In case of a line diagram, different values are represented by the length of the
lines, drawn vertically or horizontally.
Multiple Bar Diagram: This type of diagram, also known as compound bar diagram, is used
when comparisons are to be shown between two or more sets of data. A set of bars for a period
or a related phenomena are drawn side by side without gaps.
One-dimensional diagrams: In case of one-dimensional diagrams, the magnitude of the
characteristics is shown by the length or height of the bar. The width of a bar is chosen arbitrarily
so that the constructed diagram looks more elegant and attractive.

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