Organization, Tabulation and Presentation of Data
The collected data also known as raw data is always in an unorganized form and needs to be organized and presented in a meaningful and readily comprehensible form in order to facilitate further statistical analysis. We can present the collected data by classification, tabulation, diagrammatic and graphical presentation
Classification condenses data into an easily assimilable form, it removes unnecessary details, facilitates comparison and highlights significant aspects of data. Broadly, we can classify the data Chronologically, Geographically, Qualitatively Quantitatively.
The first step in the direction of putting observations in some ordered form is to arrange them in ascending or descending order of magnitude. The data are then said to be in an array. You can show the same data differently by condensing these data by pairing each value with its frequency.
Tabulation is the process of summarizing classified or grouped data in the form of a table so that it is easily understood and an investigator is quickly able to locate the desired information from the data arranged in columns and rows. Thus, a statistical table makes it possible for the investigator simplify and compare data. It also enables easy diagrammatic representation and computation of statistical measures for the purpose of analysis.
The diagrammatic or visual representation uses diagrams or graphs to represent data. A diagram is a direct or analogical representation. Diagrams make the reasoning process more natural and understandable to humans.
Graphs are used for many different reasons, and can be seen everywhere, because they help us to communicate information. Many different types of graphs exist, and each one is useful in a unique way. We shall have a look at a few graphs:
Line Graph: They are good at showing specific values of data. Given one variable the other can easily be determined. Trends in data are shown clearly, and this makes predictions easy.
Bar Graph: They make comparisons between the variables very easy to perceive.
Just like a line graph they clearly show trends in data.
Pie Charts: The circle of a pie graph represents 100%. Each portion that takes up space within the circle stands for a part of that 100%. An important point to be noted is that pie charts can be misleading if one or more of the parts of the whole are left out. If a part of the whole is left out, then it increases the percent values of the other parts that are displayed.
Some other forms of representing data graphically are:
- Frequency polygons
- Pareto Chart