02 data collection

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Statistical DataCollection &

Sampling

Techniques


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2

It is a capital mistake to theorize

before one has data.

-Sir Arthur Conan Doyle as SherlockHolmes


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How important is it?

Data collection is an extremely importantpart of any research because the

conclusions of a study are based on whatthe data reveal.

There are several ways of collecting data.The choice of procedures usually dependson the objectives and design of the studyand the availability of time, money andpersonnel.


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Examples of data

Demographic information such as age,sex, household size, civil status orreligion.

Social and economic information such aseducational attainment, health status,extent of participants in socialorganizations, occupation, income,

housing condition and the like.

Scores in exams, grades, etc.


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Types of Research Data

Generally classified as:1. quantitative or

2. qualitative

Types based on their source:

1. Primary

2. Secondary


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Quantitative and Qualitative Data

1. Quantitative Data

- are information which can becounted or expressed in numericalvalues.

Ex: age, grades, income, test score,number of children, level ofsatisfaction, amount of sales, lengthof service, etc.


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2. Qualitative Data

These are descriptive information which hasno numerical values.

Ex: attitude or perception towards something,

process used in accomplishing an activity, apersons experiences, ones idea about

certain concepts, situation, or phenomenonlike drug abuse , family planning,

immunization, etc.


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Primary and Secondary data

According to source, data mayalso be classified as Primary or

secondary. Two importantquestions to be considered are:Who will provide that data?

Where will the data be collected?


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Primary Data

These are informationcollected directly from thesubjects being studied,such are people, areas, or

objects


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Primary Data - Examples

o Surveys

o Focus groups

o Questionnaireso Personal interviews

o Experiments and observational

study


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Secondary Data

These are information collected

from other available sources, like

recent censuses, or data collectedby large scale national or worldwide surveys, such as agriculture

and industry surveys, demographicand health surveys, data ofcompleted studies.


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Secondary DataExamples of

Sources

o City/municipal health offices

o Vital Statistics birth, death certificates

o

Hospital, clinic, school nurse recordso Private and foundation databases

o City and government records

o Surveillance data from governmentprograms

o Census, NSO, etc.


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Techniques of Collecting Data

The choice of the best way to collect datadepends largely on the type of data to becollected and the source of data. Before

starting to collect data, a researchershould decide:

A. What data to collect,

B. Where or from whom the data will beobtain,

C. What instrument/s or device/s to use incollecting the data.


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METHODS OF COLLECTING DATA:

1. Surveys

a. Interview method

b. Indirect/questionnaire method2. Registration method3. Observation method


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Survey Types

Surveys can be

descriptive or explanatory

involve entire populations or samplesof populations

capture a moment or map trends

can be administered in a number ofways


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Survey Construction

Survey construction involves

formulating questions and response

categorieswriting up background information

and instruction

working through organization andlength

determining layout and design


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less expensive than an interview.

Less time - consuming

Can cover greater number of respondents

Can easily gather data.

Can give confidential response since theycan answer them in private.

Answers obtained are free from anyinfluence from the interviewer.


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Yield limited responses. Cannot ask morequestions

Mailed questionnaire -less turn-out/ High

proportion of non-return Can be influenced by coaching.

Tends to yield wrong information since it givesincomplete information

Questionnaires cannot be used on illiteraterespondents.


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a face to face interaction between thedata collector (the interviewer), andthe source of information (the

respondent).The interviewer directly asks the

respondent questions from a

prepared instrument, which is calledan Interview Schedule.


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involves asking respondents a series ofopen-endedquestions

can generate both standardized

quantifiable data, and more in-depthqualitative data

However, the complexities of people

and the complexities of communicationcan create many opportunities formiscommunication andmisinterpretation


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Interview Types

Interviews can range from

formal to informal

structured to unstructuredcan be one on one or involve

groups


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The interviewer can observe thebody language of the respondent.

The interviewer can probe forclarification of ambiguousresponses.-raise as many questions

Interview is effective for semi-literateor illiterate respondents.

The expected response rate in aninterview is high.


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More expensive because of travel cost.

Skilled interviewer is required. Trainingis needed for those who lack experience

and/ or those who are not yet skilled inconducting interviews.

Time-consuming

May give bias response to theinterviewer which for him can satisfy theinterviewer.


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In-depth interview

To answer Howand Whyquestions

USE FGD OR KII.

1. Example: In a Study about domestic violence, with avictim as key informant, the interviewer may ask:

Some people believe that men have the right to

discipline their wives. Do you share the same belief?(Probe) Why or why not?

2. In a study on students attitude towards cheating inclass, with teachers as key informants, the interviewermay ask:

Why do you think student cheat? (Probe) Can youexplain what you mean by habit?

Is cheating rampant in your classes? How rampant it is?(Probe) Why is it so?

Focus Group Discussion (FGD)


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Observation - oldest

A. Participant Observation

B. Non-Participant Observation

Content Analysis


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Observation

relies on the researchers ability to gatherdata through their senses - and allowsresearchers to document actual behaviourrather than responses related to behaviour

However, the observed can act differentlywhen surveilled, and observations can betainted by a researchers worldview

Hawthorne's effect


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Observation Types

Observation can range from

non-participant to participant

candid to covertfrom structured to unstructured


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Experimentation explores causeand effect relationships by

manipulating independent variablesin order to see if there is acorresponding effect on a

dependent variable


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Experimentation

Pure experimentation requires both

a controlled environment and the

use of a randomly assigned controlgroup

This can be difficult to achieve in

human centred experimentsconducted in the real-world


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Data collection choice

What you must ask yourself:

Will the data answer my research

question?


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To answer that

You much first decide what your

research question isThen you need to decide what

data/variables are needed to

scientifically answer the question


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If that data exist in secondary form,

then use them to the extent you

can, keeping in mind limitations.But if it does not, and you are able

to fund primary collection, then it is

the method of choice.


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Main aim: to obtain a samplethat is representative of the

target population


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- attempt to select units such

that each has a definable

probability of being chosen.

- attempts to ensure that each

unit has the same chance ofbeing included as every other

unit in the sample frame.


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- are all sampling procedures in which theunits that make up the sample are

collected with no specific probability

structure in mind.Examples: volunteer respondents, most

easily accessible (in geographical terms,

payment for participation, considered by

the researcher as in some way typical ofthe target population, units are chosen

with no obvious design


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Methods of Sampling

Simple Random sampling

Systematic sampling

Convenience sampling Stratified sampling

Quota Sampling


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Simple Random Sampling Selection so that each individual member has an

equal chance of being selected (eg. Roll of dice,random number tables, fishbowl method)

Systematic Sampling Select some starting point and then select every

kth element in the population


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Convenience Sampling Use results that are easy to get


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Stratified Sampling First need to split the population into sub-populations Draw a sample from each stratum


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- interviews, mail surveys, telephone

surveys are some examples.

- is based on defining the distribution of

characteristics required in the sample,and selecting respondents until a quota

has been filled.

Example: 50 women, 50 men


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Assignment : by pair (1 yellow

paper)

Look for 5 theses (published orunpublished, local or international) at thelibrary or the internet.

Cite the title of the study and the authorsproperly.

Identify the IV and the DV of the study.

Identify the sampling method used in thestudy

NOTE: No Same Study Please


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Study:

Demographics vs. epidemiology

Latest Philippine Demographic profile

National Health Situation

Top ten leading cause of deaths

Formulas and computations on:

Mortality rate (infant & maternal)

Morbidity rate

Crude birth rate

Crude death rate

Incidence rate


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5 members per group

Submit a letter to the medical director ofany hospital in Midsayap (MDC,AMADO, COHESCO, Pesante) to allow

you to interview their billing and recordspersonnel.

Submit to me a copy of the letterapproved by the medical director.

Topics co ered


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Topics covered:

1. Population census

2. Percentage of occupancy3. Mortality/morbidity rates

4. Computation of bills (Length of

stay/discharge)5. Miscellaneous rates


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02 data collection

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