Can a questionnaire be reliable but not valid?
A measure can be reliable but not valid, if it is measuring something very consistently but is consistently measuring the wrong construct. Likewise, a measure can be valid but not reliable if it is measuring the right construct, but not doing so in a consistent manner.
What makes a questionnaire reliable and valid?
Validity looks at the extent to which a survey instrument measures what we want to measure. Reliability considers the extent to which the questions used in a survey instrument consistently elicit the same results each time it is asked in the same situation on repeated occasions.
How do you know if a questionnaire is reliable?
How do we assess reliability? One estimate of reliability is test-retest reliability. This involves administering the survey with a group of respondents and repeating the survey with the same group at a later point in time. We then compare the responses at the two timepoints.
Which is more important reliability or validity?
Validity is harder to assess than reliability, but it is even more important. To obtain useful results, the methods you use to collect your data must be valid: the research must be measuring what it claims to measure. This ensures that your discussion of the data and the conclusions you draw are also valid.
How do you validate a self made questionnaire?
Questionnaire Validation in a Nutshell
- Generally speaking the first step in validating a survey is to establish face validity.
- The second step is to pilot test the survey on a subset of your intended population.
- After collecting pilot data, enter the responses into a spreadsheet and clean the data.
How do you develop and validate a questionnaire?
Developing a Questionnaire
- Identify the dimensionality of the construct.
- Determine the format in which the questionnaire will be administered.
- Determine the item format.
- Item development.
- Determine the intended length of questionnaire.
- Review and revise initial pool of items.
- Preliminary pilot testing.
- Summary.
What is the difference between reliability and validity?
Reliability and validity are concepts used to evaluate the quality of research. They indicate how well a method, technique or test measures something. Reliability is about the consistency of a measure, and validity is about the accuracy of a measure.
How do you test validity?
Test validity can itself be tested/validated using tests of inter-rater reliability, intra-rater reliability, repeatability (test-retest reliability), and other traits, usually via multiple runs of the test whose results are compared.
What is the reliability of the 4 th questionnaire?
The 4 th questionnaire item (Q4) has the weakest correlation with the other items, and removing this questionnaire item from the scale would improve the reliability, increasing Cronbach’s alpha to 0.893. In this blog we have discussed various approaches to assessing reliability. Reliability and validity are interconnected.
How is the validity of a questionnaire checked?
Concurrent validity As the name implies, this validity check is the degree to which the scores on a questionnaire correlates with the test on another already established questionnaire distributed during the same period, or another valid test available at the same time.
Which is more important, reliability or validity?
Despite being very different, both reliability and validity are important in research. As the saying goes ‘a valid test is always reliable but a reliable test is not necessarily valid’, but it is important to ensure that both reliability and validity are demonstrated. Like Loading… 3 bloggers like this. This entry was posted in Uncategorized.
How is the reliability of a survey assessed?
In this blog we have discussed various approaches to assessing reliability. Reliability and validity are interconnected. If a survey has poor reliability it will have poor validity. However, good reliability does not necessarily mean a survey will have good validity. Soon we’ll post another blog considering validity.
