While performing any statistical investigation, we need to collect the raw data. But the data that we collect in the original form is so huge and endless that we cannot come to any conclusions and predictions just by looking at it at a glance. We need to process it, arrange it in some desired order and use them for certain analysis. So we can say that we use the statistical techniques to collect, summarize, analyze, compare and interoperate the data to come to certain conclusions. This data arrangement can be in frequency table form, tally table form, in form of class mark or sometimes in form of graphical representation.
These days’ people spend lots of money in advertisement and publishing pictures. Most of the time we come across the data presented in form of graphs which gives the pictorial presentation to attract the customers to go for their particular product. These pictures show the benefits of buying a particular brand of car or scooter in compare to other brands, to use a particular brand of cosmetics in compare to other brands and even some times this graphic representation attract us to eat any particular brand products in comparison to other brands. Besides this we also see the graphical representation of data showing us to attract to buy any particular brand of the newspaper. These graphs are also used to view the election results time to time showing the status of different political parties in different regions.
The reason behind the graphical presentation of data is to look at the glance and come at certain conclusions and predictions instantly. We observe that common people do not take Interest in the numerical form of data or the predictions which come as the conclusion of that data. Person is instantly attracted towards the graphical presentation of the same data which is in form of different pictures for immediate analyzing of data. It helps in comparative study of the given data which is in Numbers. So with the purpose to convey the correct meaning, the Data Analysis chart must be properly titled and properly labeled. Different types of graphs can be drawn by which different types of data can be analyzed and give certain predictions. Some of the common methods of representing data through graphs are Bar charts, Histograms, polygons, pie charts, frequency curves and even plotting different graphs like temperature graph, sales of the week and other such data are presented by the graphs. There are many advantages of presenting the data in form of graphs.
If a graph is properly constructed, then graphs always show readily information which may be lost otherwise if the data is shown in form of the numerical data only.
It helps us to predict the trend in which the changes are occurring and the effects of these changes are observed and then further steps are taken which is the main aim of the Statistics, yes we do agree that the same data is also available in the form of table and can be used to come to certain conclusions, but every time, everyone is not so analytic to analyze the data and predict the right result from the available data.
The objectives of presenting the graphical presentation are as follows:
1. It helps us to view the complex data in the simpler form.
2. Graphs always help us to have an attractive, interesting and impressive view in compare to a table. All the special features of the data are visible at a glance and it becomes easy to view the rise and the down fall. It makes easy to look at the trends and the fluctuations that exist in the raw data which is rather impossible to look at, when the data is in the raw or even the tabular form.
3. It saves the time and the efforts of the statisticians as well as the observer to predict the results from the given graphs which are drawn with the help of data once collected.
4. The job of comparison becomes easy and simple by us of graphical presentation of data.
5. Every data conveys a message which becomes easy to understand with the help of the graph. A person who looks at the graph does not require any special knowledge of mathematics to understand it.
While drawing a simple graph following general rules must be remembered:
a. Proper title of the graph must be mentioned.
b. All independent variables must be represented on ‘X’ and ‘Y’ axis, which must always begin from (zero, zero) i.e. the origin of the graph.
c. Proper scale caption must be mentioned on ‘x’ and ‘y’ axis.
d. Suitable scale must be taken to draw the graph and then it should be mentioned on the top right corner of the graph.
e. Graph must be plotted neatly.