2. ◤
BIASED SAMPLING ERROR
Biased sampling error, as the name suggests, may arise due
to certain preferences at the time of collection of samples.
3. ◤
UNBIASED SAMPLING ERROR
In some cases, collection of samples is to be done keeping a set of
conditions in mind. However, it is also required that such conditions
do not bring about a bias in the process of sample collection, failing
which, an error arising out of such bias is termed as ‘Unbiased
sampling error
4. ◤
CAUSES OF SAMPLING ERRORS
1) Faulty Selection, Process :
In some cases, a certain kind of samples may be selected that will
help reach a desired result. This bias in selection of a sample can
cause sampling errors.
2) Substitution :
There may be cases where a collected sample may not be able to
enumerate the results that are desired. In such cases, the
surveyors may substitute a particular sample member for another
similar member that may lead to inaccurate results.
5. ◤
3) Faulty Demarcation of Sampling Units :
A faulty method of separation of sampling units may also lead to
such an error
6. ◤
TYPES OF NON SAMPLING ERRORS
▪ FRAME ERROR
▪ NON RESPONSE ERROR
▪ MEASUREMENT ERROR
▪ DATA PROCESSING ERROR
▪ DATA ANALYSIS ERROR
7. 1) Frame Error :
All the elements of the target population, which can be selected to form
a sample are called sampling frame. An error arising due to an
incomplete or inaccurate sample frame may be defined as a frame
error.
2) Non-Response Error :
It is almost impossible to obtain data from each and every respondent
covered in the same. There are always some respondents who refuse
to give any information. Thus, non-response error occurs when
respondents refuse to cooperate with the interviewer by Sampling
errors may arise due to the following not answering his questions
8. 3) Measurement Error :
At the time of data collection, a respondent may not necessarily give a
true picture, due to innumerable reasons. This leads to an inaccurate
result as the information that is collected is not based on fact
4) Data Processing Error :
Data processing refers to the process of systematic categorization of
data to make the process of analysis easier and more accurate.
However, errors may occur at the time of categorizing data, such as,
drawing up of tables, coding responses, etc.
9. 5) Data Analysis Error :
Data analysis errors may be defined as those errors that arise due to
the application of incorrect statistical techniques or formulas that give
the wrong result. These errors may be simple as well as complex.
10. ◤
CAUSES FOR NON SAMPLING
ERRORS
1) Faulty Planning and Definitions :
Non sampling errors arise due to improper definition of samples,
lack of trained surveyors, improper definition of target population,
etc.
2) Response Errors :
Response errors may be defined as errors that arise due to
variations in responses of participants from actual facts.
11. ◤
3) Non-Response Errors :
Following may be the reasons for non-response errors :The respondent is
unavailable even after repeated efforts to get in touch with the same.
The respondent is not willing to answer some or all of the questions.
The respondent is unable to respond to all questions or provide
information pertaining to the same.
12. ◤
4) Errors in Coverage :
Lack of ability to cover all sampling units gives rise to such errors.
5) Compiling Errors :
Compiling errors are those that arise due to erroneous editing and
coding of data by the researcher.
