Data Collection biostats BJ revised 2021.ppt

maths

1. 1
Overview of Data
Collection Methods
Dr B Jokomo

2. 2
Learning Objectives
Describe various data collection techniques and
state their uses and limitations
Understand the benefits of using a combination of
different data collection techniques
State various sources of bias in data collection and
ways of preventing bias
Identify ethical issues involved in implementing
research and ways of ensuring that study
participants are not harmed

3. 3
Overview
Data collection techniques systematically collect
information about the subjects of study i.e. people,
objects, phenomena and about the settings in which
they occur.
Very important: If this is done in a haphazard way it
will be difficult to answer the research questions in
a conclusive way

4. Quantitative and Qualitative methods
•2 types of research methods
•Qualitative
•Quantitative
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5. Types of research
Quantitativeresearch is concerned with
questions about: how much? How many?
How often? To what extent? Etc
Quantitative –used to quantify the size,
distribution and association of variables
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6. Types of research
Qualitative is concerned with finding the answers
to questions which begin with: why? In what way?
How?
Why people behave the way they do
Opinions and attitudes
How people are affected by the events that go
on around them
Why certain occurrences have happened
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7. Qualitative
Qualitative -identify and explore variables that give
insight into the nature and causes of certain
problem
e.g through use of Focus Group Discussions,
Participant observation
In-depth interviews
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8. 8
Data Collection Methods
Using Available Information
Observing
Interviewing
Administering written Questionnaires

9. 9
Using Available Information
Thisinvolvesuseofinformationcollectedby
others,locatingsourcesandretrievingthe
information
•Serviceinformationsystemdata,
•Censusdata
•Unpublishedreports,
•Publications
Tool-checklisthastobedesignedpayingspecial
attentiontothelayoutofthesourcedocuments
fromwhichdataaretobeextracted

10. 10
Advantages and Disadvantages of Existing Data
Limitations
Access to the data may be difficult
Information may not always be
complete and precise.
Data from available source may be out
of date
Authenticity of information
Limited variables available
Variables inconsistently defined
&recorded by different people at
different times
Advantages
Inexpensive
Quick although time
often underestimated
Allows historical
comparison
Data not influenced
by project

11. 11
Observation
Involves systematically selecting, watching and recording
behavior and characteristics of humans, objects and
phenomena
Participant observationThe observer or researcher takes part in
the situation under investigation
Non Participant Observation The observer or researcher
watches the situation openly or concealed but does not
participate
NB Observation on objects e.g. measure weight, height,
blood pressure

12. 12
Advantages and disadvantages of using the
observation method
Advantages
Gives additional reliable
information on behavior of
people than interviews and
questionnaires
Checks on information
collected especially on
sensitive topics such as
alcohol or drug use
Can be a primary source of
data
Disadvantages
Time consuming therefore
useful in small scale studies
Can be subjective-bias
Participant observation –
ethics?

13. 13
Interviews
Involves oral questioning of respondents either individually
or as a group.
Can be
Face to face
Telephone
Answers obtained can be tape recorded and transcribed
•Key Informant interviews (understanding of problem –
exploratory)

14. 14
Advantages and Disadvantages of Interviews
Advantages
They have a high degree of
flexibility
Excellent way of discovering
subjective meanings and
interpretations that people give
to their expectations
People’s responses are less
influenced by their peers if
conducted individually.
They give access to events or
activities that cannot be
observed directly.
No need for respondents
literacy
Disadvantages
Social pressure on the
respondent
Time consuming & expensive
Respondent may be feel
inhibited on sensitive topics
Interpersonal factors/
suspicion of respondent
interfering with data collection
Infringes on privacy

15. 15
Questionnaires
Can be administered by the researcher or be self administered
Two types of questions
•Closed (Yes or NO)
•Open ended (Allows for further elaboration)

16. 16
Advantagesand Disadvantages of questionnaires
Advantages
Ensures privacy and
anonymity
Respondents are on their
own therefore likely to give
honest responses
Easy to administer, reduces
time and financial expenses
Can reach a large group in
short space of time
Disadvantages
No proportions of returns
No control over data
quality & form completion
Lack clarification and
further probing
Responses are short and
lack detail
Introduction of researcher
bias
Not suitable for illiterates

17. Postal Questionnaires
Can cover wide
geographic region
Limited to respondents
with fixed contactable
addresses
Generally low response
rate (<30%)
Unsure who filled in the
questionnaires
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18. Telephone Surveys (Type of Individual interview)
Can cover a wide
area
Exclusion of people with unlisted
numbers or no phones (bias)
Non verbal cues absent-affects
communication
Questionnaire has to be short-
thereby limiting information
Suspicion aroused when call
received at home
Call being ignored-unfamiliar
number
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19. 19
Differentiation between Data Collection
Techniques and Tools
Datacollectiontechniques
•Using available
information
•Observation
•Interview
•Questionnaires
•FGD
Data collection tools
Checklist, data compilation
forms (Case Record
Forms)
•Eyes and other senses, pen
and paper, watches, scales
microscope
•Schedules,checklist,
questionnaires,taperecoder
•Questionnaires
•taperecorder,FGDGuide

20. Focus Group Discussion
Qualitative method of data collection
Group discussion of 6-12 people guided by a
facilitator
Group members talk freely and spontaneously about
a certain topic
More than a question and answer session or
interaction
Group members discuss the topic among
themselves
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21. Purposes of FGD
Obtainindepthinformationonconcepts,
perceptions,andideasofagroup
Develop relevant research hypotheses
To focus research
Exploring in greater depth the problem to be
investigated and its possible causes
Formulate appropriate questions
Explore controversial topics
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22. Strengths of FGDs
Learning not just what the participants think, but why
they think that way
More natural and more flexible , since the researcher
creates the discussion
Implementation of FGDs is an iterative process-
each FGD building on previous one-slighty
elaborated or better focussed set of themes and
discussions
Powerful research tool providing valuable
spontaneous information at a short time and low cost
Can complement surveys or other qualitative and
quantitative techniques
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23. Limitations of FGDs
Not to be used for quantitative purposes
Testing of hypothesis or generalisation of findings
which require more elaborate services
Not advisable to use FGDs as a single tool.-
combine with Key Informant Interviews and in depth
interviews
On very sensitive topics like sexual behaviour or
LWHIV people may feel inhibited to express
themselves openly
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24. Triangulation
Researchers often use combination of techniques
, loosely structured interviews using open ended ?s
-focus group discussions
-observations
These are termed qualitative research techniques.
They produce qualitative information which is often
recorded in narrative form.
Use of different data collection techniques is called
triangulation
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25. Triangulation cont..
Qualitative Research Technique
Involves the identification and exploration of a
number of often related variables that give
insight into the nature and causes of certain
problems and into the consequences of those
affected.
Quantitative Research Techniques
These are used to quantify the size, distribution,
and association of certain variables in the study
population.
Both techniques are often used within a single study-
(Mixed methods).
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26. 26
Bias in Information collection
Bias in information collection is a distortion that
results in the information not being representative
of the true situation
Possible Sources of bias during data collection
1.Defective instruments
Questionnaires with
-Fixed or closed questions on topics about
which too little is known

27. Bias cont..
-Open ended questions without guidelines on
how to ask or answer
-Vaguely phrased questions or
-Questions asked in illogical order
Weighing scales that are not standardised
Preventionby carefully planning the data
collection process and by pretesting the
data collection tools.
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28. 28
2. Observer Bias
Can easily occur during observation or loosely
structured interviews
Data collector seeing or only hearing what they are
interested in and missing information that is critical
to the research

29. Prevention of Observer bias
Prevention:
•prepare guidelines for conducting loosely
structured interviews
•train data collectors
•data collectors should work in pairs and discuss
findings after the observation
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30. 30
3. Effect of the Interview on the informant
Possible factor in all interview situations
Informant mistrusting intention of the interview, avoiding
certain questions or giving misleading answers

31. Prevention
-Adequately introduce the purpose of the
study to informants
-Take sufficient time to do the interview
-Assure respondents that data collected will
be confidential
Awareness of potential biases can enable
you to prevent them. If unsuccessful
report honestly ways in which your data
may be biased.
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32. 32
Ethical Considerations
Need to consider whether our research procedures
likely to cause any physical or emotional harm
Causes of harm
–Violating informants rights to privacy by posing
sensitive questions or by gaining access to
records that may contain personal data
–Observing the behaviour of informants without
their being aware
–Failing to observe or respect certain cultural
values, traditions, or taboos

33. Prevention
–Obtaining informed consent before the study or
interview begins
–Building rapport before discussing sensitive
issues
–Ensuring confidentiality of the data obtained
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