# B.Com 1st Year Diagrammatic & Graphic Presentation Short Notes

B.Com 1st Year Diagrammatic & Graphic Presentation Short Notes :- In this post You will Find B.com Notes Study material Unit Wise Chapter Wise Topic Wise division of the content. This Post is very useful for all the Student B.A., B.Sc., B.Com., M.A., M.Com.

Q.1. What do you mean by diagrammatic representation of data?

Ans. Diagrams play an important role in the presentation of statistical data. They are interesting and attractive and convey the message to a layman rather easily as compared to the other ways of data presentation. Diagrammatic presentation of data enables a person to grasp the entire information at a glance. Such diagrams are comparable and appealing.

Inadiagrammatic presentation of statistical data, the geometric figures like bars, squares, rectangles, circles, etc. are used. In it, data is classified according to some chronological order, geographical region or attributes. Maps are generally used for geographical presentation of statistical data.

Diagrams do not add any new meaning to the statistical facts but they exhibit the results more clearly. They are easy to understand as compared to the figures and occupy an important place because they provide simple and intelligible presentation of data and save time and labour.

Q.2. What are the characteristics of a good diagram? Give the general rules for constructing diagrams.

Ans. Characteristics: Following are the characteristics of a good diagram:

1. It should be as simple as possible.

2. It must represent the data accurately.

3. It should be neat and clean and according to the size of paper.

4. The units must be clearly stated in it.

5. The diagram should have a clear and complete title.

6. Original data for diagram should be given.

7. A proper scale must be selected to prepare a diagram.

General Rules: Following are the rules that must be observed in the construction of diagrams:

1. The title should be given on the top in bold letters and should be self-explanatory.

2. Selection of a proper scale is important. The diagrams should neither be too small nor too large and should suit the size of the paper.

3. The dimensions of a diagram should be related to the ease of construction, reading, suitable for presentation.

4. Various colours, shades and designs should be used to different parts of the diagram.

5. Selection of proper diagram is significant. There are various diagrams each having its special characteristic.

Q.3. What is graphic presentation? What are the rules for constructing a graph?

Ans. Graph is the simplest aid to the numerical reading that gives a picture of numbers in such a way that the relations between the two series can be compared easily. Graphic presentation of data is becoming popular now-a-days.

General Rules: Following rules are followed while graphing statistical data:

1. There should be a proper, concise and clear title on the top of every graph paper so as to indicate the facts presented by the graph.

2. Its framework must be such that independent variable is placed on the horizontal axis and the dependent variable on the axis. form of presentation of data.)

3. Both of horizontal and vertical lines should be carefully located so as to provide the best possible appearance for the graph.

4. The scale must be selected such that it can accommodate the whole data.

5. The scale selected should be mentioned on the top right hand side of the graph paper.

6. The principle of drawing graph is that the vertical scale must start from zero. False base line is used for effective presentation of fluctuation in data if the minimum of the values of dependent variable are very small related to their magnitude.

7. If more than one variable is plotted on the same graph, it is necessary to distinguish them by different lines.

8. An index should be used to explain the meaning of different types of lines or curves.

9. The ratio or logarithmic scale should be used to show proportional changes.

10. Source of data and necessary notes should be given so as to estimate the accuracy and reliability of data.

11. It is necessary to make the graph effective and attractive to have neatness and simplicity.

12. Original data should be mentioned to maintain the accuracy of graphical presentation if needed.

Q.4. What are the basic differences between diagrams and graphs?

Ans. Difference between Diagrams and Graphs: Though there is no clear-cut line of demarcation between the two, yet following points of difference may be noted:

1. For constructing a graph we generally make use of graph paper whereas a diagram is generally constructed on a plain paper. In other words, a graph represents mathematical relationship (though not necessarily functional) between two variables whereas a diagram does not.

2. Diagrams are more attractive to the eye and as such are better suited for publicity and propaganda. They do not add anything to the meaning of the data and therefore from the point of view of a statistician or research worker they are not helpful in analysis. On the other hand, graphs are very much used by the statistician and the research worker in analysis.

3. For representing frequency distributions and time series, graphs are more appropriate than diagrams. In fact, for presenting frequency distributions, diagrams are rarely used.

Q.5. Write a note on graphs of time series/Historigrams.’

Ans. Time series stands for the numerical record of the changes in a variable during a given period of time. Time units are placed on the OX-axis and the values of variables are measured on the OY-axis. The data is plotted by placing the points that are connected by a continued smoothed line called as curve that show the probable changes at all possible time intervals to which the data relate. Such a curve is known as ‘Historigram’.

They can be constructed in two ways:

1. Historigrams on Natural Scale: A natural scale graph is used to show the absolute values of a time series. Such graphs can be absolute historigrams or index historigrams.

(a) Absolute historigrams are graphs when original data or actual values of the time series areplotted on it. They can be absolute historigrams of one dependent variable where only one factor is shown on the OY-axis and time is measured on OX-axis and absolute historigrams of two or more dependent variable where two or more variables can be represented on the same graph.