2. 2.1 Collecting Data
Primary sources of statistical data are government institutions,
business agencies, and other organizations
Secondary sources are books, encyclopedia, journals,
magazines, and research or studies conducted by other
individuals.
1. The Direct or Interview Method
In this method, the researcher has a direct contact with the
interviewee.
3. 2. The Indirect or Questionnaire Method
This method makes use of a written questionnaire. The researcher
gives or distributes the questionnaire to the respondents either
by personal delivery or by mail.
3. The Registration Method
This method of collecting data is governed by laws.
4. The Experimental Method
This method is usually used to find out cause and effect
relationship. Scientific researchers often use this method.
4. 2.2 Determining the Sample Size
To determine the sample size, the Slovin’s formula is used.
𝑛 =
𝑁
1 + 𝑁𝑒2
where n = sample size
N = population size
e = margin of error
5. N = 10 000
e = 10% or 0.10
𝑛 =
𝑁
1 + 𝑁𝑒2
𝑛 =
10 000
1 + (10 000)(0.10)2
n = 99.01 or 99
6. N = 10 000
e = 5% or 0.05
𝑛 =
𝑁
1 + 𝑁𝑒2
𝑛 =
10 000
1 + (10 000)(0.05)2
n = 384.62 or 385
7. 2.2.1 Sampling Techniques
Sampling technique is a procedure used to determine the
individuals or members of a sample.
2.2.2 Probability Sampling
Probability Sampling is a sampling technique wherein each
member or element of the population has an equal chance of
being selected as members of the sample.
9. 2.2.2.2 Systematic Random Sampling
taking the 𝑘 𝑡ℎ units from an ordered population, from the 1st unit
which is selected at random.
2.2.2.3 Stratified Random Sampling
The word stratified comes from the root word strata which means
groups or categories (singular is stratum). When we use this
method, we are actually dividing the elements of a population
into different categories or subpopulations and then the
members of the sample are drawn or selected proportionally
from each subpopulation.
10. 2.2.2.4 Cluster Sampling
Sampling wherein groups or clusters instead of individuals are
randomly chosen
2.2.2.5 Multi-Stage Sampling
2.2.3 Non-probability Sampling
Sample are drawn form the population based on the judgment of
the researchers. The results of a study using this sampling
technique are relatively biased. This technique lacks objectivity.
11. 2.2.3.1 Convenience Sampling
sample being drawn from that part of the population that is close
to hand.
2.2.3.2 Quota Sampling
non-probabilistic version of stratified sampling.
2.2.3.3 Purposive Sampling
sample is selected based on characteristics of a population and
the objective of the study.
2.2.3.4 Snowball Sampling
existing respondents recruit future subjects from among their
acquaintances.
