techniques of data collection

1. PRESENTATION BY
MANOJ KUMAR SUNUWAR
NIMS COLLEGE, LAGANKHEL
LALITPUR, NEPAL
Date: 2069-08-12

2. CENSUS METHOD OF DATA COLLECTION
 In census method of data collection, all the
elements or cases of the field of study area are
enumerated.
 The information is collected from all the possible
units in the universe in the census method.
 In this method of data collection, we have to apply
the technique of total counting of possible units.
 For example: if the average daily expenditure of
students of NIMS college is to be calculated, then
daily expenditure figures would be obtained from
each and every student of NIMS college. Then
total expenditure is divided by total number of
students and we get average expenditure.

3. Merits:
1. Complete information can be obtained about
the whole populations.
2. Data obtained from this method are more
accurate, reliable and representatives.
3. In census method, no item is left out. So, the
data will be adequate.
4. This method is quite useful when the field of
study is not big and intensive (lot of work to be
done in a short time) survey is to be made.
5. Data obtained from the complete enumeration
can be used in various investigations.

4. Demerits:
1. It is more expensive, labour and time
consuming method of data collection.
2. It is not applicable if the population size is
infinite or very large in size.
3. It contains errors due to non-response,
biasness of respondents.
4. Some errors or wrong information may enter
in an inquiry due to less efficiency of
enumerator.
5. It is not reliable if it destroys each and every
item at the time of testing.

5. SAMPLING METHOD OF DATA COLLECTION
 The representative parts of the population is
called sample. If the investigation is done by
using the representative parts of the population
then it is known as sampling method of data
collection.
 Based on this sample, inference is drawn for the
entire population.
 In this method, a part is selected from the
population and examined, then it is called
sample enumeration or sample survey.
 Sample survey will usually be less expensive
than a census survey and the desired
information will be obtained in less time.

6.  Less expensive does not imply that economy is
the consideration in conducting sample survey. It
is most important that a degree of accuracy is
also maintained.
 Occasionally, the techniques of sampling survey
is applied to verify the result obtained from
census survey.
 It has been well established fact that in many
situations a well conducted sample survey can
provide much more precise result than from
census survey.
 In this method only selected sample represents
the whole population.

7.  For example: if we are going to study about the
spending behaviour of the students who are
studying management in Kathmandu. Then,
among all students studying management in
Kathmandu we select only 500 students under
study. This 500 students are the sample of
whole possible number of students studying
management in Kathmandu. On the basis of
spending behaviour of this 500 students, we
can draw conclusion for whole population.
 The main objectives of this method is to draw
conclusion about whole population by taking
small units of population.

8.  Examples of sampling which we can face in our
daily life are:
 A cook tastes some pieces of rice or pulse
whether it is properly cooked or not.
 A pathologist or doctor examines few drops of
blood to draw the conclusion about the blood
constitution of the whole body.
 A business man gives order for the commodities
by examining only small sample of the same
commodity.
Merits:
1. Reduce cost, manpower and time of the survey.
2. Greater speed of getting result.

9. 3. More trained and skilled manpower can be
used so there is chances of getting greater
accurate result.
4. This method is very useful to check the
reliability of census survey.
5. If population size is very large, then this is
the only appropriate method of data
collection and taking correct result.
Demerits:
1. The sample should be collected by experts.
Otherwise, the result provides wrong
conclusion.

10. 2. If the investigator is biased in the process of
data collection. Then, it does not provide
reliable and accurate result.
3. If the sample selected from the population is
not the representative one, then it may yield
wrong conclusion.
4. Selection of sample units and sample size is
difficult task.
5. If there is lack of full co-operation between
enumerator and informants, at that situation
we can get wrong information. Which, affects
the result of the investigation.

11. METHODS OF SAMPLING
 On the basis of objective of investigation,
nature of the available data, time and cost,
we have to select actual method of sampling.
 There are various methods of sampling used
in practice, which should be known before
taking the sample.
 The sampling procedures that are commonly
used may be broadly classified under two
headings:
A. Probability Sampling
B. Non-Probability Sampling

12. A. Probability Sampling
 Probability sampling is a scientific method of
selecting samples from the population based
on some laws of chance, in which each unit in
population has some probability of being
selected in the sample. It can be categorized
under following categories:
a. Simple Random Sampling.
b. Stratified Random Sampling.
c. Systematic Sampling.
d. Cluster Sampling.
e. Multi-Stage Sampling.

13. B. Non-Probability Sampling
 The selection of samples without any
probability rule is called non-probability
sampling. In this method investigator selects
sample from the population by using his own
experience and judgement.
 Some of the non-probability samplings are:
a) Judgement or Purposive Sampling.
b) Accidental Sampling.
c) Convenient Sampling.
d) Quota Sampling.
e) Snowball Sampling.