Classification of data
The method of arranging data into homogenous classes according to some common features present in the data is called classification.
A planned data analysis system makes fundamental data easy to find and recover. This can be of particular interest for legal discovery, risk management and compliance. Written methods and set of guidelines for data classification should determine what levels and measures the company will use to organise data and define the roles of employees within the business regarding input stewardship. Once a dataclassification scheme has been designed, security standards that stipulate proper approaching practices for each division and storage criteria that determine the data’s lifecycle demands should be discussed.
Objectives of Data Classification
The primary objectives of data classification are:
 To consolidate the volume of data in such a way that similarities and differences can be quickly understood. Figures can consequently be ordered in a few sections holding common traits.
 To aid comparison.
 To point out the important characteristics of the data at a flash.
 To give importance to the prominent data collected while separating the optional elements.
 To allow a statistical method of the material gathered.
Theory Questions:
Q.1 GIVE THE MEANING/DEFINITION OF CLASSIFICATION OF DATA.  
ANSWER:  
(A) MEANING OF CLASSIFICATION OF DATA 

(B) DEFINITION OF CLASSIFICATION GIVEN BY PROF. SECRIST  “Classification is the process of arranging data into sequences according to their common characteristics or Separating them into different related parts.” 
Q.2 WHAT ARE THE OBJECTIVES OR FUNCTIONS OF CLASSIFICATION?  
ANSWER:  
OBJECTIVES / FUNCTIONS OF CLASSIFICATION 

Q.3 WHAT IS MEANT BY VARIABLE? BRIEFLY EXPLAIN ITS TWO KINDS.  
ANSWER:  
(A) MEANING OF VARIABLE 

(B) KINDS OF VARIABLE:  
(i) DISCRETE VARIABLE 

(ii) CONTINUOUS VARIABLE 

METHODS OF CLASSIFICATION
Q.1 BRIEFLY EXPLAIN THE BASIS OR METHODS OF CLASSIFICATION.  
ANSWER:
FOLLOWING ARE THE BASIS OF CLASSIFICATION: 

(1) GEOGRAPHICAL CLASSIFICATION 

(2) CHRONOLOGICAL CLASSIFICATION 

(3) QUALITATIVE CLASSIFICATION 

(4) QUANTITATIVE CLASSIFICATION 

STATISTICAL SERIES
Q.1 WHAT IS A STATISTICAL SERIES? BRIEFLY DISCUSS THE VARIOUS KINDS OF
STATISTICAL SERIES. 

ANSWER:  
(A) STATISTICAL SERIES 


(B) STATISTICAL SERIES CAN BE DIVIDED AS:  
(a) ON THE BASIS OF GENERAL CHARACTERISTICS  On the basis of general characteristics, statistical series are of three kinds:
(i) Time Series (Chronological Series) If the different values that a variable has taken in a period of time are arranged in chronological order, the series so obtained is called a time series. (ii) Spatial Series (Geographical Series) The data arranged according to location or geographical considerations form a spatial series. (iii) Condition Series In this series, data are classified according to the changes occurring in variable according to a condition, such as Height, Weight, Age, Marks, Income etc. 

(b) ON THE BASIS OF CONSTRUCTION  According to construction, statistical series can be categorized as :
(i) INDIVIDUAL SERIES Individual series refers to that series in which items are listed singly, i.e. each item is given a separate value of measurement. Example: 

MARKS (Out of 50)  20  30  10  30  40  50  45  40  42  40  
(ii) DISCRETE SERIES
A discrete series is that series where individual values differ from each other by definite amount. Example: 

MARKS  12  25  35  45  49  
NO. OF STUDENTS  3  5  2  2  1  
(iii) CONTINUOUS SERIES
A continuous series is that series which represents continuous variables, showing a range of values of different items of the series. Example: 

MARKS  0 – 10  10 – 20  20 – 30  30 – 40  40 – 50  
NO. OF STUDENTS  1  4  5  6  4  
TYPES OF CONTINUOUS SERIES & THEIR CONVERSION
Q.1 BRIEFLY DISCUSS THE VARIOUS TYPES OF CONTINUOUS SERIES.  
ANSWER:  
(A) EXCLUSIVE SERIES  Age (in Years)  No. of Students 

0 – 10  3  
10 – 20  5  
20 – 30  12  
30 – 40  6  
40 – 50  4  
In the above example,
– There are 5 Class. – Class Size = l_{2}– l_{1}=10 (for all) 

(B) INCLUSIVE SERIES  Age (in Years)  No. of Students 

0 – 9  3  
10 – 19  5  
20 – 29  12  
30 – 39  6  
40 – 49  4  
(C) MID VALUE SERIES  Mid Values  (f) 

5  3  
15  5  
25  12  
35  6  
45  4  
(D) OPEN ENDED SERIES (DISTRIBUTION)  Age (in Years)  No. of Students 

BELOW 10  3  
10 – 20  5  
20 – 30  12  
30 – 40  6  
40 & ABOVE  4  
(E) CONTINUOUS SERIES WITH UNEQUAL INTERVAL  (X)  (f) 

0 – 10  3  
10 – 15  5  
15 – 30  12  
30 – 40  6  
40 – 45  4  
(F) CUMULATIVE FREQUENCY DISTRIBUTION
“LESS THAN CF DISTRIBUTION” 
Age (in Years)  No. of Students 

Less Than 10  3  
Less Than 20  8  
Less Than 30  20  
Less Than 40  26  
Less Than 50  30  
“MORE THAN CF DISTRIBUTION”  Age (in Years)  No. of Students  
More Than 10  30  
More Than 20  27  
More Than 30  22  
More Than 40  10  
More Than 50  4  
SHORT QUESTIONS: 
Q.1 WHAT IS MEANT BY CLASSIFICATION OF DATA? 
ANSWER:
Classification of data is the process of arranging data in groups or classes on the basis of certain properties. 
Q.2 WHAT IS MEANT BY GEOGRAPHICAL CLASSIFICATION? 
ANSWER:
When the data are classified according to geographical location or region, it is known as geographical classification. 
Q.3 WHAT IS QUANTITATIVE CLASSIFICATION? 
ANSWER:
When data is classified on the basis of characteristics which can be measured, it is known as quantitative classification. 
Q.4 DEFINE QUALITATIVE CLASSIFICATION. 
ANSWER:
When data is classified on the basis of attributes, it is known as qualitative classification. 
Q.5 GIVE THE NAMES OF STATISTICAL SERIES ON THE BASIS OF CONSTRUCTION. 
ANSWER:
(i) Time Series; 
Q.6 WHAT IS A CLASS? 
ANSWER:
‘Class’ means a group of numbers, in which items are placed such as 010, 1020, 2030, etc. 
Q.7 WHAT DO YOU UNDERSTAND BY THE CLASS LIMITS? 
ANSWER:

Q.8 WHAT IS MEANT BY MAGNITUDE OF A CLASS? 
ANSWER:

Q.9 WHICH SERIES EXCLUDE THE UPPER LIMIT OF THE CLASSINTERVAL? 
ANSWER: Exclusive Series. 
Q.10 WHAT IS MEANT BY MIDPOINT? 
ANSWER:

Q.11 WHICH METHOD INCLUDES BOTH THE CLASS LIMITS IN THE CLASS OF A CONTINUOUS SERIES? 
ANSWER: Inclusive Method. 
Q.12 WHAT IS MEANT BY THE TERM ‘FREQUENCY’? 
ANSWER:
Frequency refers to number of times a given value appears in a distribution. 
Q.13 WHAT IS A FREQUENCY DISTRIBUTION? 
ANSWER:
A table, in which the frequencies and the associated values of a variable are written side by side, is known as a frequency distribution. 
Q.14 WHAT DO YOU UNDERSTAND BY RAW DATA? 
ANSWER: A mass of data in its original form in known as raw data. 
Q.15 NAME THE SERIES, WHICH HAVE CLASSINTERVAL. 
ANSWER: Continuous Series. 
Multiple Choice Questions:
Q.1 Which of the following is the objective of classification 
a. To condense mass of data.
b. To present data in simple, logical and understandable form. c. To bring out points of similarity and dissimilarity among various groups. d. All of the above 
Q.2 Temperature, Height, Weight, Marks are example of 
a. Discrete Variable
b. Continuous Variable c. Both a and b d. None of the above 
ANSWER KEY 
1d, 2 b 
Q.NO  FILL IN THE BLANKS 
1  _________ of data is the process of arranging data into homogeneous groups according to their common characteristics. 
Q.NO  ANSWER KEY 
1  Classification 
The abovementioned concept is for CBSE class 11 Statistics for Economics – Meaning and Objectives of Classification of Data. For solutions and study materials for class 11 Statistics for Economics, visit BYJU’S or download the app for more information and the best learning experience.