extent to which a measurement instrument (e.g. tool, test or
questionnaire) is dependable, stable and consistent when
repeated under identical conditions.
refers to the ability of the scale to provide consistent,
stable information across time and across respondents.
about the consistency and trustworthiness of research findings and it
is often considered in relation to the issue of whether a finding is
reproducible
reliability of a specific scale or measurement tool/instrument is assessed statistically
enhanced by a range of measures that are set
out in the study protocol
Training
Calibration
Monitoring and conducting tests
test at different times or by different researchers
extent to which an instrument or scale (e.g. laboratory
test, questionnaire) measures what it is supposed to
measure (e.g. do IQ tests validly measure the construct
of IQ?).
most published research where an instrument is used, the
researchers usually compare their instrument with a 'gold
standard' measure.
maintained in quantitative research when studies are
conducted using the strict rules and standards
appropriate for the study design and the measurement
instruments.
rules of quantitative validity should NOT be applied to qualitative research.
not inherent to the measurement tool or instrument
but should be evaluated within the context of how the
test or instrument is to be used and the specific
population from which the study sample has been
drawn.
evidence for the tool's validity is not quickly or easily
assessed but is gathered over time
Responsiveness
ability of the instrument to measure change following an intervention over time.