Question

Write explanatory notes on:

1) General principles for constructing diagram

2) Multiple bar diagram

3) Frequency curve.

Answer 1

1. The following principles should be followed while constructing a diagram:

i. Title: Every diagram should be assigned a short and brief title explaining the components of the diagram.
ii. Proportion: In the diagrammatic presentation, it is very important that the diagram maintains a proper proportion between the height and the width.
iii. Scale: Diagrams should be constructed with the help of a proper geometric instrument and scale.
iv. Footnote: In every diagram, a footnote concerning relevant information about the diagram should be provided below the diagram.
v. Index: An index should be given at the right-hand side of the diagram describing various kinds of shades, columns, etc.
vi. Simplicity: The diagram should be as simple as possible and should be easily understandable.
vii. Accuracy: The representation of the given set of data should be accurate and exact.
viii. Source: The source of the data should always be provided below the diagram.

2. Multiple bar diagrams are used to represent two or more sets of interdependent and interrelated data in a simple manner. In such diagrams, different colours and designs are used to represent bars and compare sets of data.

3. A frequency curve is a curve obtained by joining the top midpoints of all rectangles of a histogram using a free hand. A frequency curve must be drawn such that the total area under the curve is proportional to the total frequency. When a frequency polygon is smoothed out, it is known as a frequency curve.