actual relationship does exist; when the researcher
accepts the null hypothesis when it should have
been rejected
uncertainty Degree to which alternatives are
perceived relative to the occurrence of an event
and the probability of these alternatives
unimodal A data set with one mode, such as a
normal distribution
univariate analysis The use of statistical tests to
provide information about one variable
unstructured observations A method of data
collection associated with qualitative research
in which phenomena of interest are allowed to
emerge over time as observations are made
validity The degree that an instrument mea-
sures what it is supposed to measure
visual analog scale Ratio-level scale of a 100-mm
line anchored on each end with words or symbols
vulnerable population A special group of
people needing protection because of members’
limited ability to provide informed consent or
because of their risk for coercion
wheel of professionalism in nursing A model
depicting behaviors of the professional nurse
wildcards Symbols substituted for one or more
letters in a search term
Willowbrook studies An unethical study involv-
ing coercion of parents to allow their children to
participate in the study in exchange for admission
to a long-term care facility
within-groups design Comparisons are made
about the same subjects at two or more points in
time or on two or more measures
z scores Standardized units used to compare
data gathered using different measurement
scales530 GLOSSARY