This document discusses data collection methods. It defines data collection as gathering numerical measurements or information on variables of interest in an established systematic way. There are two main sources of data: documentary sources like published reports and field sources like individuals with knowledge of the study topic. Common data collection methods include direct interviews, indirect questionnaires, registration of existing data, observation, and experiments. The document also outlines how to plan a study, including determining sample size, selecting sampling techniques, and creating structured versus open-ended questions. It discusses probability and non-probability sampling methods.

1. COLLECTION OF DATA

2. A process of obtaining
numerical
measurements

3. process of gathering and measuring
information on variables of interest, in an
established systematic fashion that enables
one to answer stated research questions,
test hypotheses, and evaluate outcomes

4. TWO SOURCES OF DATA

5. 1. Documentary Sources
Published or unpublished
reports, statistics, Internet,
letters, magazines,
newspapers, diaries, etc

6. a. Primary Data
Data gathered are original

7. b. Secondary Data
Data is taken from an original
source which is computed and
compiled.

8. 2. Field Sources
Individuals who have sufficient
knowledge and experience
regarding the study under
investigation.

9. METHODS USED IN
DATA COLLECTION

10. 1. The Direct Method
referred as interview method
face to face encounter

11. 2. The Indirect Method
questionnaire method
questionnaire-lists of questions

12. 3. The Registration Method
utilizing the existing
data/fact/info which is kept
systemized by the office
concerned

13. 4. The Observation Method
used to collect data pertaining
attitudes, behaviour, values, and
cultural patterns of the samples
under investigation

14. 5. The Experiment Method
cause and effect relationship
used in making a scientific
inquiry

15. PLANNING THE STUDY

16. 1. Estimate the
number of items
in the population.

17. 2. Assess resources
such as time and
money

18. 3. Determine the
sample size using
the Slovin’s formula

19. n = N
1 + Ne2
see table 1: Sample size for a Specified Margin of Error on page 21
n = sample size
N = population size
e = margin of error

20. 4. Pick the sample by
using the appropriate
sampling technique.

21. 5. Prepare the questions to
be asked in the
interview or in the
questionnaire.

22. TYPES OF QUESTIONS

23. 1. Structured Question
one way or few alternatives
clear, simple, objective and
easy to answer and tabulate

24. 2. Open-ended Questions
can be answered in many
ways-probing or questions
w/c elicit reasons

25. FEATURES OF A GOOD
QUESTIONNAIRE

26. short and clear
avoid leading questions
always state the precise units

27. can be answered y checking slots or stating
simple names or brands
arrangement of questions should e
carefully planned
limit questions to essential information

28. Two Major Ways of
Selecting Sample Units from
a Population

29. known as simple random
sampling
picking things at random means
picking things without bias or any
predetermined choice
A. Probability Sampling

30. Ways of Drawing Sample
Units at Random

31. numbers assigned to each
member of the population
1. Lottery Sampling

32. the selection of each member of
the population is left adequately
to chance, and every member of
the population has an equal
chance of being chosen
2. Table of Random Numbers

33. used when there are only few
sample units to be selected
a. Direct Selection Method

34. Two Ways of Conducting the
Remainder Method:
b. Remainder Method

35. 1. When the number taken from
the table of random numbers is
subtracted from the upper limit
within which this number falls, the
remainder is the sample unit.
b. Remainder Method

36. 2. When the upper limit of the set is
subtracted from the number taken
from the random tables and yields a
number equal or less than N, the
remainder is the sample unit.
b. Remainder Method

37. used when the population is too
large to handle
B. Restricted Random Sampling

38. TYPES OF RESTRICTED
RANDOM SAMPLING

39. units are obtained by drawing
every nth element of the
population
1. Systematic Sampling

40. nth = Total no. of elements in the population
Desired Sample Size
nth = N
n

41. ex: population 50,000; sample size 100; margin of
error 10%. Determine the nth term
nth = N
n
= 50,000/100
= 500

42. a. Stratified Sampling
 the population is divided into groups based on
homogeneity
 the distribution of units is proportional to the
total number of units in each stratum
Types of Systematic Sampling

43. 1) Identify N and its different strata
2) Divide the members of the population into
percent shares
3) multiply each percent share by n sample units
to get the actual number of sample units for
each stratum
steps:

44. Example
population is 50,000
sample units is 100
margin of error is 10 %
25,000 belong to high income group
10,000 belong to middle income group
15,000 belong to low income group
strata

45. STRATA NUMBER OF
POPULATION
High-income group 25,000
Middle-income group 10,000
Low-income group 15,000
TOTAL 50,000

46. STRATA NUMBER OF
POPULATION
PERCENT SHARE
(N/n)
High-income
group
25,000/50,000
Middle-income
group
10,000/50,000
Low-income
group
15,000/50,000
TOTAL 50,000
0.5 or 50%
0.2 or 20%
0.3 or 30%
100%

47. STRATA Sample size times the
percent share
Number of Sample Units
High-income
group
100 x 0.5
Middle-income
group
100 x 0.2
Low-income
group
100 x 0.3
TOTAL
50
20
30
100

48. b. Cluster Sampling
 an area sample: geographical basis
 districts or blocks
heterogeneous groups
Types of Systematic Sampling

49. c. Multi-Stage Sampling
 uses several stages in getting the samples
from the general population
 useful in conducting a nationwide survey
Types of Systematic Sampling

50. not all members of the population are given
equal chances: sample
non-probability sampling
chooses its sample
used in market research or employment
department
2. Non-Random Sampling

51. a. Purposive Sampling
 choosing samples based on a criteria and rules
by the researcher
Types of Non-Random Sampling

52. b. Quota Sampling
 the researcher limits the number of his
samples based on the required number of
subject under investigation
Types of Non-Random Sampling

53. c. Convenience Sampling
 the researcher conducts a study at his
convenient time, preferred place or venue
Types of Non-Random Sampling