Practical reseaerch 1 lesson 1 quarter four

1. PRACTICAL RESEARCH 1

2. Lesson Objectives:
Define Population
1
Define Sample and Sampling.
2
Identify the difference of population and
sample.
3

3. Sampling Procedure and
Sample

4.  refers to the totality of objects, elements,
person and characteristics under a given
condition. In other words, population
refers to the entire group that you want
to draw conclusions about
 the larger group from which individuals
are selected to participate in a study
POPULATION

5.  is the specific group that you will col
lect data from which also refers as t
he subset in a population.
 is “a smaller (but hopefully represen
tative) collection of units from a pop
ulation used to determine truths abo
ut that population” (Field, 2005)
Sample

6. is the process of technique
of choosing a sample from
a population to participate
in the study.
Sampling

7. Non-probability Sampling
Procedures

8. Convenience Sampling
is defined as a method adopted by researchers
where data is collected from a conveniently av
ailable pool of respondents. It is the most com
monly used sampling technique as it’s incredi
bly prompt, uncomplicated, and economical. In
many cases, members are readily approachabl
e to be a part of the sample.
the process of including whoever happens to
be available at the time …called “accidental”
or “haphazard” sampling

9. • Easiest, cheapest and least
time consuming.
• In pilots study we use this
sampling technique
ADVANTAGES

10. • Sample is not representative
of entire population
• Result cannot be generalized
for entire population.
DISADVANTAGES

11.  is defined as a non-probability sampling method in
which researchers create a sample involving indivi
duals that represent a population. Researchers cho
ose these individuals according to specific traits or
qualities. These samples can be generalized to the
entire population. The final subset will be decided
only according to the interviewer’s or
researcher’s knowledge of the population.
 the bases of the quota are usually age, gender, edu
cation, race, religion, & socio-economic status.
Quota Sampling

12. For example,
if the basis of the quota is college level & t
he research needs equal representation, wit
h a sample size of 100, he must select 25 firs
t- year students, another 25 second year stu
dents,49 25 third-year, & 25 fourth-year stud
ents.

13. • Economically cheap, as there is no
need to approach all the
candidates.
• Suitable for studies where the field
work has to be carried out, like
studies related to market & public
opinion polls.
ADVANTAGES

14. DISADVANTAGES
• Not represent the entire population.
• In the process of sampling these su
bgroups, other traits in the sample
may be overrepresented.
• Bias is possible, as investigator/int
erviewer can select persons known
to him.

15. Snowball Sampling
or chain-referral sampling is defined a
s a nonprobability sampling technique
in which the samples have traits that
are rare to find. This is a sampling
technique, in which existing subjects
provide referrals to recruit samples
required for a research study.

16. It is a nonprobability sampling technique that
is used by researchers to identify potential
subjects in studies where subjects are hard
to locate such as commercial sex workers,
drug abusers, etc.
 For example, a researcher wants to conduct
a study on the prevalence of HIV/AIDS among
commercial sex workers.
Snowball Sampling

17. • The chain referral process allows the r
esearcher to reach populations that ar
e difficult to sample when using other
sampling methods.
• The process is cheap, simple, & cost-
efficient.
• Need little planning & lesser workforce
ADVANTAGES

18. • Researcher has little control over
the sampling method.
• Representativeness of the
sample is not guaranteed.
• Sampling bias is also a fear of
researchers when using this
sampling technique.
DISADVANTAGES