Introduction to Statistics
UNIT 1 INTRODUCTION TO STATISTICS
Structure
1.0 Introduction
1.1 Objectives
1.2 Meaning of Statistics
1.2.1 Statistics in Singular Sense
1.2.2 Statistics in Plural Sense
1.2.3 Definition of Statistics
1.3 Types of Statistics
1.3.1 On the Basis of Function
1.3.2 On the Basis of Distribution of Data
1.4 Scope and Use of Statistics
1.5 Limitations of Statistics
1.6 Distrust and Misuse of Statistics
1.7 Let Us Sum Up
1.8 Unit End Questions
1.9 Glossary
1.10 Suggested Readings
1.0 INTRODUCTION
The word statistics has different meaning to different persons. Knowledge of
statistics is applicable in day to day life in different ways. In daily life it means
general calculation of items, in railway statistics means the number of trains
operating, number of passenger’s freight etc. and so on. Thus statistics is used by
people to take decision about the problems on the basis of different type of
quantitative and qualitative information available to them.
However, in behavioural sciences, the word ‘statistics’ means something different
from the common concern of it. Prime function of statistic is to draw statistical
inference about population on the basis of available quantitative information.
Overall, statistical methods deal with reduction of data to convenient descriptive
terms and drawing some inferences from them. This unit focuses on the above
aspects of statistics.
1.1 OBJECTIVES
After going through this unit, you will be able to:
Define the term statistics;
Explain the status of statistics;
Describe the nature of statistics;
State basic concepts used in statistics; and
Analyse the uses and misuses of statistics.
5
, Introduction to Statistics
1.2 MEANING OF STATISTICS
The word statistics has been derived from Latin word ‘status’ or Italian ‘Statista’
meaning statesman. Professor Gott Fried Achenwall used it in the 18th century.
During early period, these words were used for political state of the region. The
word ‘Statista’ was used to keep the records of census or data related to wealth
of a state. Gradually, its meaning and usage extended and thereonwards its nature
also changed.
The word statistics is used to convey different meanings in singular and plural
sense. Therefore it can be defined in two different ways.
1.2.1 Statistics in Singular Sense
In singular sense, ‘Statistics’ refers to what is called statistical methods. It deals
with the collection of data, their classification, analysis and interpretations of
statistical data. Therefore, it is described as a branch of science which deals with
classification, tabulation and analysis of numerical facts and make decision as
well. Every statistical inquiry should pass through these stages.
1.2.2 Statistics in Plural Sense
‘Statistics’ used in plural sense means that quantitative information is available
called ‘data’. For example, information on population or demographic features,
enrolment of students in Psychology programmes of IGNOU, and the like.
According to Websters “Statistics are the classified facts representing the
conditions of the people in a State specifically those facts which can be stated in
number or in tables of number or classified arrangement”.
Horace Secrist describes statistics in plural sense as follows : “ By Statistics we
mean aggregates of facts affected to a marked extent by multiplicity of causes
numerically expressed, enumerated or estimated according to reasonable standard
of accuracy , collected in a systematic manner for a pre-determined purpose and
placed in relation to each other.” Thus Secrist’s definition highlights following
features of statistics:
i) Statistics are aggregate of facts: Single or unrelated items are not considered
as statistics.
ii) Statistics are affected by multiplicity of causes: In statistics the collected
information are greatly influenced by a number of factors and forces working
together.
iii) Statistics are numerical facts: Only numerical data constitute statistics.
iv) Statistics are enumerated or estimated with a reasonable standard of
accuracy: While enumerating or estimating data, a reasonable degree of
accuracy must be achieved.
v) Statistics are collected in a systematic manner: Data should be collected by
proper planning by utilising tool/s developed by trained personnel.
vi) Statistics are collected for a predetermined purpose : It is necessary to define
the objective of enquiry, before collecting the statistics. The objective of
enquiry must be specific and well defined.
6
UNIT 1 INTRODUCTION TO STATISTICS
Structure
1.0 Introduction
1.1 Objectives
1.2 Meaning of Statistics
1.2.1 Statistics in Singular Sense
1.2.2 Statistics in Plural Sense
1.2.3 Definition of Statistics
1.3 Types of Statistics
1.3.1 On the Basis of Function
1.3.2 On the Basis of Distribution of Data
1.4 Scope and Use of Statistics
1.5 Limitations of Statistics
1.6 Distrust and Misuse of Statistics
1.7 Let Us Sum Up
1.8 Unit End Questions
1.9 Glossary
1.10 Suggested Readings
1.0 INTRODUCTION
The word statistics has different meaning to different persons. Knowledge of
statistics is applicable in day to day life in different ways. In daily life it means
general calculation of items, in railway statistics means the number of trains
operating, number of passenger’s freight etc. and so on. Thus statistics is used by
people to take decision about the problems on the basis of different type of
quantitative and qualitative information available to them.
However, in behavioural sciences, the word ‘statistics’ means something different
from the common concern of it. Prime function of statistic is to draw statistical
inference about population on the basis of available quantitative information.
Overall, statistical methods deal with reduction of data to convenient descriptive
terms and drawing some inferences from them. This unit focuses on the above
aspects of statistics.
1.1 OBJECTIVES
After going through this unit, you will be able to:
Define the term statistics;
Explain the status of statistics;
Describe the nature of statistics;
State basic concepts used in statistics; and
Analyse the uses and misuses of statistics.
5
, Introduction to Statistics
1.2 MEANING OF STATISTICS
The word statistics has been derived from Latin word ‘status’ or Italian ‘Statista’
meaning statesman. Professor Gott Fried Achenwall used it in the 18th century.
During early period, these words were used for political state of the region. The
word ‘Statista’ was used to keep the records of census or data related to wealth
of a state. Gradually, its meaning and usage extended and thereonwards its nature
also changed.
The word statistics is used to convey different meanings in singular and plural
sense. Therefore it can be defined in two different ways.
1.2.1 Statistics in Singular Sense
In singular sense, ‘Statistics’ refers to what is called statistical methods. It deals
with the collection of data, their classification, analysis and interpretations of
statistical data. Therefore, it is described as a branch of science which deals with
classification, tabulation and analysis of numerical facts and make decision as
well. Every statistical inquiry should pass through these stages.
1.2.2 Statistics in Plural Sense
‘Statistics’ used in plural sense means that quantitative information is available
called ‘data’. For example, information on population or demographic features,
enrolment of students in Psychology programmes of IGNOU, and the like.
According to Websters “Statistics are the classified facts representing the
conditions of the people in a State specifically those facts which can be stated in
number or in tables of number or classified arrangement”.
Horace Secrist describes statistics in plural sense as follows : “ By Statistics we
mean aggregates of facts affected to a marked extent by multiplicity of causes
numerically expressed, enumerated or estimated according to reasonable standard
of accuracy , collected in a systematic manner for a pre-determined purpose and
placed in relation to each other.” Thus Secrist’s definition highlights following
features of statistics:
i) Statistics are aggregate of facts: Single or unrelated items are not considered
as statistics.
ii) Statistics are affected by multiplicity of causes: In statistics the collected
information are greatly influenced by a number of factors and forces working
together.
iii) Statistics are numerical facts: Only numerical data constitute statistics.
iv) Statistics are enumerated or estimated with a reasonable standard of
accuracy: While enumerating or estimating data, a reasonable degree of
accuracy must be achieved.
v) Statistics are collected in a systematic manner: Data should be collected by
proper planning by utilising tool/s developed by trained personnel.
vi) Statistics are collected for a predetermined purpose : It is necessary to define
the objective of enquiry, before collecting the statistics. The objective of
enquiry must be specific and well defined.
6
