Branches, sources of data, merits and demerits of statistics

Basic Statistics

We can understand the meaning of statistics from the following definitions :

According to Prof. Horace Secrist  “ Statistics is an aggregate of facts affected to a marked extent by the multiplicity of causes, numerically expressed, enumerated or estimated according to a reasonable standard of accuracy, collected in a systematic manner for a predetermined purpose and placed in relation to each other ".

According to Croxton and Cowden  " Statistics may be defined as the collection , presentation ,analysis and interpretation of numerical data ". 

Branches of statistics:

1. Descriptive statistics
It relates to the collection and presentation of data in different forms such as graphs, tables and diagrams to describe or represent the data in a simpler way. Companies use this branch of statistics to prepare annual reports, financial accounts, etc.

2. Inferential statistics
It is about the techniques used for the analysis of data, computing estimations and drawing conclusions from them. These estimations are drawn from the sampling and its testing. Future events forecasts are predicted and made from this type of statistics.  

Statistics deals with the collection of data.

Sources of data:

1. Primary source
They are also known as statistical source. They are obtained directly in the field. Census and surveys are used to obtain data here.

2. Secondary source
Also known as non-statistical source, are obtained from the already existing records(data collected primarily) from different governmental and non governmental organisations.

Now let's look into the merits and demerits of statistics :

Merits:

1.Allows to present facts in a definite form .
2.Facilitates comparison .
3.Facilitates predictions/forecasts .
4.Formulation of suitable policies .
5.Simplifies the data .

Demerits:

1.Does not deal with individual measurement.

2.Excludes qualitative information.

3.Result is only an average. We ignore the bigger picture .

4.Bias is possible.

Now let’s learn about averages, also known as the measures of central tendency.

First let’s know the meaning of average ;It is a value to represent a series of data.

Its functions are similar to the merits of statistics.

Essentials of a good average:

1. Should be simple to calculate.

2. Should be easy to understand.

3. Should be rigidly defined.

4.Should be based on all items of observations.

These are the main types of averages:

1.Mean

2.Median

3.Mode