6. questionnaire design and validation by dr bony (14 november 2013).pptx
TRANSCRIPT
BONY WIEM LESTARIEPIDEMIOLOGY AND BIOSTATISTICS DEPARTMENT
2012
QUESTIONNAIRE DESIGN AND VALIDATION
1. Distinguish between various stages in questionnaire design.
2. Demonstrate appropriate techniques for wording questions
3. Validity and Reliability of measurement tool
4. Identify appropriate delivery format of certain questionnaire
Learning Objectives:
What is Questionnaire
?
A TOOL FOR COLLECTING INFORMATION TO DESCRIBE, COMPARE, EXPLAIN, KNOWLEDGE, ATTITUDES, BEHAVIORS, AND/OR DEMOGRAPHIC CHARACTERISTICS ON A PARTICULAR TARGET GROUP
1. Self administered (mailed or personal contact)
2. In person (face-to-face) interviews
3. Telephone interviews
Questionnaire General Format:
Types of Questions:
1. Open-ended questions• Permit free response which should be
recorded in the respondents’ own words.
2. Closed questions• Have a list of possible options or
answers from which the respondents must choose.
Identify: (Self learning)
1. Advantages & disadvantages of open-ended questions
2. Advantages & disadvantages of closed questions
Steps in Designing A Questionnaire
1. Content Take your objectives and variables as a starting point
2. Formulating questions– Formulate one or more questions that will provide the
information needed for each variable– Check whether each question measures one thing at a time– Avoid leading questions– Avoid words with double or vaguely defined meanings or
that emotionally laden– Ask sensitive questions in a socially acceptable way
Steps in Designing A Questionnaire
3. Sequencing the questions– Design your interview schedule or questionnaire to
be ‘informant friendly’– Use simple, everyday language
4. Formatting the questionnaire5. Translation
If interviews will be conducted in one or more local languages, the questionnaire should be translated in order to standardise the way questions will be asked.
Steps in Questionnaire Development: (Cohen)
Conceptualization:abstract construct – conceptual definition – operationalization - indicator
Constructing
Testing
Analysis
Revising
Penting !!!
Questionnaire is a tool:
• The quality of a measurement: validity and reliability
Validity: • the extent to which a test measures what it is
intended to measure• Free of systematic error• Accuracy
Questionnaire is a tool:
Reliability:• The degree to which a variable has nearly the same
value when measured several times• Free of random error (chance)• Precision• Also called reproducibility, consistency• Assessing precision (reproducibility of repeated
measurement):– Within – between observer– Within – between instruments
Reliability:
• Reliability coefficient ~ correlation coefficient (0 – 1)• A questionnaire is reliable when the
minimum reliability coefficient is 0.7
Assessing Validity:
• Criterion validity (predictive and concurrent)depending on whether the criterion refers to a current or future assessment
• Construct validityassembly evidence to support or refute a complex scientific theory and to show under what circumstances it holds true
Assessing Validity:
• Content validity– refers to comprehensiveness– how adequate the sampling of questions reflects
the aims of the index that were specified in the conceptual definition of its scope
FINAL REMARKS:
• prior to using a questionnaire it has to be established that the instrument is valid and reproducible in the context (i.e. population, setting and study design) in which it is going to be employed.
• conceptually comparable (conceptual equivalence)• developing a new questionnaire is very time-
consuming• burden on respondents• practical aspects of the study
REFERENCES:
1. Measuring Health: A Guide to Rating Scales and Questionnaire. Ian McDowell and Claire Newell. 1996.
2. Psychological Testing: Design, Analysis and Use. Lisa Friedenberg. 1995.
3. Designing and Conducting Health System Research Projects. KIT Publishers. WHO. 2003
What’s Your Message?THANK YOU