The document discusses the fundamental goals of questionnaire design, focusing on achieving maximal reliability and validity in data collection. It outlines the concepts of validity, including content, construct, and criterion validity, which address whether a test accurately measures its intended purpose. Additionally, the importance of reliability, defined as the consistency of measurement, is emphasized in ensuring the accuracy of research findings.

1. BY:
Vinu Arpitha K.S [16DM020]
Nida Khanam[16DM027]
Chandan[16DM028]

2. Contents
• Introduction
• Validity
• Types of validity
• Reliability
• Methods of reliability

3. Introduction
• There are two basic goals in questionnaire design.
• To obtain information relevant to the purposes of the survey.
• To collect this information with maximal reliability and validity.
• How can a researcher be sure that the data gathering instrument being
used will measure what it is supposed to measure and will do this in a
consistent manner?
• This can be answered using validity and reliability.
• The process of developing and validating an instrument is in large part
focused on reducing error in the measurement process.
• Reliability estimates evaluate the stability of measures, internal consistency
of measurement instruments.

4. Validity
• Validity can be defined as the degree to which a test measures what it is
supposed to measure
• Extent to which an empirical measure adequately reflects the real meaning
of the concept under consideration
• Validity is done mainly to answer the following questions:
• Is the research investigation providing answers to the research questions for which it
was undertaken?
• If so, is it providing these answers using appropriate methods and procedures?

5. Types of Validity

6. Content Validity
• It refers to the connections between the test items
and the subject-related tasks.
• The test should evaluate only the content related
to the field of study in a manner sufficiently representative,
relevant, and comprehensible.

7. Construct Validity
• It implies using the construct correctly (concepts, ideas, notions).
• Construct validity seeks agreement between a theoretical concept
and a specific measuring device or procedure.

8. Criterion Validity
• This approach is concerned with detecting the presence or absence of
one or more criteria considered to represent traits or constructs of
interest.
• One of the easiest ways to test for criterion-related validity is to
administer the instrument to a group that is known to exhibit the trait
to be measured. This group may be identified by a panel of experts.
Questions culled
after the control
group has taken the
test
Items should be omitted that
are drastically inconsistent