Ch. 10 Exam 2 Flashcards
(concrete things, such as O2 stat, temp, BP, weight demographic variables)
direct measurement
(abstract concepts such as pain, depression, coping, self-care, and self-esteem, anxiety level, feelings)
indirect measurement
Difference between the true measurement and what is actually measured.
measurement error
Variation in measurement is in the same direction.
systematic random error
Systematic Error Examples: A paper and pencil rating scale designed to measure hope may actually also be measuring perceived support. When measuring subjects’ weight, a scale that shows weights that are 2 pounds over the true weights.
Random Error Examples: The person completing a paper and pencil scale may accidentally mark the wrong column. The person entering the data into a computer may punch the wrong key.
concerned with how consistently the measurement technique measures the concept of interest. If expressed as a correlational coefficient, 1.00 is perfect reliability, whereas 0.00 is no reliability. The lowest acceptable coefficient for a well-developed measurement tool is 0.80 or greater. Validate —> reliability has to be reliable (0.80 —> greater).
reliability
Types of Reliability:
stability
equivalence
homogeneity
concerned with the consistency of repeated measures or test-retest reliability. Test-retest.
stability
focused on comparing 2 versions of the same instrument (alternate forms reliability) or 2 observers (interrupter reliability (data collectors)) measuring the same event.
Inter-rater reliability
Parallel forms reliability
Equivalence
addresses the correction of various items within the instrument or internal consistency. Determined by split-half reliability or Cronbach’s Alpha Coefficient. Stronger correlation —> more reliable to scale. Look at test in itself. Internal consistency.
homogeneity
This of an instrument is a determination of how well the instrument reflects the abstract concept being examined. Example: The CES-D was developed to measure the depression of patients in mental health setting. Will the same scale be valid as a measure of the depression of cancer patients? Researcher determine this by pilot-testing the scale to examine the validity of the instrument in a new population.
validity
is comparable to validity in that it addresses the extent to which the instrument measures what is supposed to in a study.
accuracy
comparable to reliability, is the degree of consistency or reproducibility of measurements made with physiological instruments.
precision
is the proportion of pts with a disease who have a + screening test.
sensitivity
is the proportion of pts without a disease who have a neg screening test.
specificity
is the % of true + who test +.
Pos predictive value
is the % of true neg who test neg.
neg predictive value
Measurement strategies in nursing:
physiological
observational
interviews
questionare
physical measurement, microbiological measurement
physiological
Unstructured observation
Structural observation: category system, checklist, and rating scales.
observational measurements
verbal comm
interviews
self-repeat form
Unstructured interview
Structured interview is similar to questionnaire (checklist)
questionnaire
What is the data collection process?
Data collection is the process of acquiring subjects and collecting study data. The steps of data collection are specific to each study and depend on the research design and measurement techniques. During the data collection process, researchers train the data collectors, recruit study participants, implement the study intervention, collect data in a consistent way, and protect the integrity of the study. The study design determines the method of selecting participants. Recruiting the number of subjects planned is critical because data analysis and interpretation depend on having an adequate sample size.
named variables
lowest of the four levels of measurement. Categories that are not more or less but different from one another in some way. Mutually exclusive and exhaustive categories. Named categories. Ex: color, race, ethnicity, marital status, medical diagnosis.
Nominal-level measurement
named + ordered variables
order/ranking imposed on categories. Numbers must preserve order. 1= tallest, 2 = next tallest, 3 = thirst tallest. Ex: pain, mobility, dyspnea, and self-care.
Ordinal-level measurement
named + ordered+ proportionate interval between variables
numerical distance between intervals. Absence of a 0 point. Likert scale. Same have to apply; has = intervals. Concepts: depression scale.
Interval-level measurement
named + order + proportionate interval between variables + can accommodate absolute zero. Highest for measurements. Continuum of values and absolute 0 point. Ex: LBS, length, volume.
ratio