Getting the sample size and Sampling techniques

1. Data Gathering
Techniques
CHAPTER 2

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.

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07819 44085 87246 47378 98338
 2.2.2.1 Simple Random Sampling
 1. Lottery Method
 2. Table of Random Numbers

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.