1. Data Collection Bakr M. Bin Sadiq Pediatric Specialist
Senior Clinical and Field Epidemiologist
Certified in International Research Ethics

2. Objectives Kinds of data collection tools and techniques
The benefits of using a combination of different data collection techniques
Sources of bias in data collection, and ways to prevent bias

3. Where to start!
Before designing a method of data collection, the researcher should write:
Detailed information on the subject of data to be collected.
Concepts to be measured in the study

4. Selecting Study Variables
Define the keywords contained in the research questions
Operationalize these keywords
Concept
Indicator
Income
Monthly net salary
GP workload
Number of patients seen
Referral rate
Patients sent to outpatients
Elderly
Aged over 65

5. Data Collection Techniques vs. Data Collection Tools
Record Sources
Checklist, formats
Observing
Eyes, pen/paper, watch, scale, microscope, checklist
Interviewing
Interview schedule, checklist, tape recorder
Focus group discussion
FGD guide, tape recorder
Written questionnaire
Questionnaire

6. Data Collection Techniques
Recorded Sources
Observation
Interview
Focus group discussion
Written questionnaire

7. Recorded Sources
A data collection technique that involves locating and analyzing information that has already been collected (old data)
Advantage
Not expensive
Permits examination of trends over the past
Disadvantage
Difficulty in gaining access (privacy)
Information recorded may be biased

8. Observation
Observation is a technique which involves systematically selecting, watching and recording behavior and characteristics of living beings, objects or phenomena.

9. Observation Advantage Disadvantage Give more detailed information
Allow to collect information on facts not mentioned in the questionnaire
Allow to test reliability of responses to questionnaire
Disadvantage
Observation bias
Presence of researcher can influence the situation

10. Interview
An interview is a data collection technique that involves oral questioning of respondents, either individually or as a group

11. Interview Advantage Disadvantage Suitable for illiterates
Clarification of questions is possible
Higher response rate
Disadvantage
Presence of researcher can influence responses
Records of events may be less complete than with observations

12. Focused group discussion
A focused group discussion consists of a group discussion in which a small number of participants (usually 6 to 12 ) of similar status under the guidance of a moderator and with at least one additional observer talk about topics of relevance to particular study.

13. Focused group discussion
Advantage
Provides in-depth qualitative information
Disadvantage
Shy participants
Domineering participants

14. Written questionnaire
A written questionnaire (self-administered) is a data collection technique in which written questions are presented that are to be answered in written form by the respondents themselves.

15. Written questionnaire
Advantage
No need of research assistant to administer it
No bias in asking the questions differently
More honest responses
Disadvantage
Not possible to use illiterate respondents
Low rate of response
Questions may be misunderstood

16. Importance of Techniques Combination
They complement each other
Maximizes the quality
Reduces the chances for bias

17. Bias in Information Collected
A bias is distortion in the data collected such that the information is no longer representative of the true situation

18. Sources of Bias Defective instruments, such as:
pre-coded questionnaire – not enough is known about the topic
semi-structured questionnaire – no guidelines on how to ask or answer
weighing scales – not standardized

19. Sources of Bias Observer bias
researcher will only see or hear things in which he is interested
it’s preferable to have two persons
information has to be recorded and discussed immediately

20. Sources of Bias Effects of interviewer on informant
informant may mistrust the intention of the researcher – give misleading answers

21. Written Questionnaire Design

22. Construction of a questionnaire
A title should be short and clear.
An address.
An identifier
Instructions: tell about the study and how to complete the questionnaire.
The layout: the questionnaire should appear neat, and attractive

23. Construction of a questionnaire
The ending: it is useful to offer a very open question right at the end.
Example:
Do you have any further points to make about this questionnaire?
Thank you for helping with this study.
Testing for problems.

24. Wording The objective should be construct questions that are: Simple.
Free of ambiguity.
Encourage accurate and honest responses without embarrassing or offending the respondent.

25. Clarity Questions must be clear and specific as possible. Example:
How much exercise do you usually get?
During a typical week, how many hours do you spend exercising?

26. Simplicity
Questions should use simple, common words that convey the idea and avoid technical terms.
Example:
“Drugs you can buy without a doctor’s prescription”
“Over-the-counter medications”.

27. Neutrality
Avoid words that suggest that there is a most desirable answer.
Example:
During the last month, how often did you smoke too much cigarettes?
During the last month, how often did you smoke more than five cigarettes in one day?

28. Types of questions There are two basic types of questions:
Open-ended questions.
Closed-ended questions.

29. Open-ended questions
Open ended questions are particularly useful when it is important to hear what respondents have to say in their own words. Example: What habits do you believe increase a person’s chance of having a heart attack? ________________________________________________________________________________________________________

30. Open-ended questions Advantages Useful for exploring new areas.
Respondents can say their own words.
Disadvantages
Require qualitative methods to code and analyze the responses, which take time and subjective judgment.

31. Closed-ended questions
Closed-ended questions are more common, these questions ask respondents to choose from one or more possible answers. Example: Which one of the following do you think increase a person’s chance of having a heart attack the most?(check one.)
Smoking
Being overweight
Stress

32. Closed-ended questions
Advantages:
Quicker and easer to answer.
Answers are easier to be analyze.
Possible answers often help clarify the meaning of the question.
Disadvantages:
Lead respondents in certain directions.
The possible answers may not include an answer that is most appropriate.

33. A structured (standardized) questionnaire
A structured (standardized)questionnaire must be carefully set out and worded.
Example:
-Total family income per month in Saudi Riyals_____
-What is your height in meter?_____

34. A structured (standardized) questionnaire
A self-administered questionnaire -Useful for straight forward information. -For large sample, cheap and quickly. An interview-administered questionnaire -Useful for complicated information. -Produces a higher response rate. -Better quality of information. -More time consuming and expensive.

35. Interviewing Methods Personal interviews Telephone surveys
Mail Surveys
Computer Direct Interviews
Surveys
Internet/Intranet (Web Page) Surveys

36. Summary Objective Speed Cost
Your choice of data collection methods will depend on several factors:
Objective
Speed
Cost