## Chapter : 1

## What Are Data-its Source And Compilation ?

## Part C - Practical Geography

- It is easy to see that there is a large amount of data available today worldwide. However, if the data is in its raw form, it might be difficult to draw logical inferences from it. As a result, it’s critical to guarantee that the measured data is algorithmically produced, logically reasoned, and statistically estimated from a variety of

sources.

- The data are collected in the following ways. These are: (i) Primary Sources (ii) Secondary Sources.

- Secondary sources are data acquired from any public or unpublished source.

**Percentage/Ratio:**Data is sometimes summarised as a ratio or proportion based on common criteria, such as literacy rate or population growth rate, percentage of agricultural or industrial output, and so on.

**Inclusive Method:**The higher limit of one class is not the lower limit of the following class in this procedure.

In the class interval, it comprises both the bottom and upper limits.

**Simple Frequencies:**It is denoted by the letter ‘f’ and represents the number of people who belong to each category.

**Exclusive Method:**In this method, a class’s higher limit is the lower limit of the following class. The class interval does not include an upper limit.

**Cumulative Frequencies:**This is denoted by the letter’ Cf, and it is calculated by summing the sums of successive simple frequencies in each group.

**Frequency Polygon:**The frequency polygon is a graph showing frequency distribution. It aids in the comparison of two or more frequency distributions. A bar diagram and a line graph are used to depict the two frequencies.

**Ogive:**Cumulative frequencies are created when frequencies are put together, and they’re listed in a table called the cumulative frequency table. An Ogive is a curve created by cumulative graphing frequencies. It may be built using either the less than or more than technique.