class 11-12 Flashcards
data collection process
goal: produce good data
-maintain controls of treatment, measurement methods, & setting
-maintain consistency in data collection process
-gather essential data - demographics & measurements of study variable
-data collection & analysis often overlap
biophysiologic measures - in vivo:
performed directly in or on living thing (e.g., bp, pulse, temperature)
biophysiologic measures -in vitro:
extracting material for analysis (e.g. biopsy, blood values)
biophysiologic measures -anthrometric:
measure body terms of composition (e.g. BMI, % body fat)
observations - unstructured
-researcher makes general notes about observed behaviours/phenomena
observations - structured
-category systems
-checklists
-rating scales
self-reports: interviews
-verbal interaction between researcher & participant
-structured or unstructured
-interviewer records data
self-reports: questionnaires
-printed/written/electronic from
-structured
-usually completed by participant
interviews (structured)
-developed interview protocol (interview schedule)
-closed and open ended questions
-interviewers trained
-standardized recording procedures
interviews (unsturctured/semi-structured):
-limited interview guide - content controlled by partipants
-greater reliance an open ended questions/cues
rating scales
rate a variable on a numerical scale
likert scales
measure opinions or attitudes on a scale (e.g. strongly agree - strongly disagree)
visual analogue scales:
plot response on a 100mm line with descriptors on each end
response set bias
-the measurement error resulting from the tendency of some individuals to respond to items in characteristics ways independently of the item content
social desirability bias
-when participants have the tendency to misrepresent their opinion in the direction of answers consistent with prevailing social norms
extreme response
-when participants select extreme response options (e.g. strongly agree) independent of the item’s content
acquiescence response
also known as the agreement bias, is the tendency for participants to agree with research statements, without the action being a true reflection of their own position or the question itself
directness of measurement
degree to which object, element, characteristic can be measured objectively
direct measurement examples
temperture, weight, o2 saturation
indirect measurement examples
e.g. depression, self-care, coping pain
measurement error (error variance)
difference between what exists in reality and what is measured by research instrument
random error
difference between the obtained measure and the actual true value, no pattern
systematic error
-measurement error that occurs consistently in the same direction
reliability
how consistently does the measurement technique measure the concept of interest
range: 0-1.00
good: 0.80
acceptable: generally 0.70
test-retest reliability (stability or reproducibility)
-degree to which retesting with the same instrument with yield the same result
-assumes the factor being tested remains the same at both testing times (e.g. IQ, Knowledge, weight)
interrater reliability (inter-observer reliability or equivalence)
-degree to which measurements remain consistent between observers
-tool used collecting data should be specific enough so that two observers would get the same results
internal consistency (homogeneity)
-degree to which all items in an instrument consistently measure the concept
-internal consistency is usually measured with Cronbach’s Alpha
measurement validity
degree to which an instrument measures the construct it is meant to measure
face validity
-degree to which the instrument looks like it is measuring the target construct
-not strong evidence validity, but may influence subjects’ attitudes towards the data measurement process
-is important when other types of validity have been established
content validity
-degree to which the content of an instrument adequately captures the construct being measured
-usually assessed by expert panel
-may measure/reported as content validity index (CVI)
criterion validity
-degree to which the scores on a measure are a replication of a “gold standard”
concurrent criterion validity
degree of correlation of two measures of the same concept at the same time
predictive criterion validity
degree of correlation between the measure of the concept and some future measure of the concept
-usually assessed by expert panel
construct validity
degree to which scores represent the construct being measured
-usually involves hypothesis testing (e.g. known-groups validity)
nominal level of measurement
-lowest of 4 levels
-attributes are only names
-categories are not more or less but different in some way
-categories mutually exclusive and exhaustive
ordinal level of measurement
-order/ranking imposed on categories
-intervals not equal
-number must preserve order
interval level of measurement
-equal distances between intervals, this distance has meaning
-absence of a zero point
ratio level of measurement
-highest of four levels
-continuum of values - ratio of two values has a meaningful interpretation (e.g. 4cm is 2x as long as 2cm)
-absolute zero point
