5060 Flashcards
research hypothesis
statement that claims a relationship exists between the independent and dependent variable
usually what the researcher is trying to prove
null hypothesis
statement that claims that NO relationship exists between the independent and dependent variable
independent variable
manipulated variable
usually the intervention being researched
dependent variable
affected by the independent variable
extraneous variables
variables that are not being studied that can affect outcome of research
experimental group
group that is being experimented on
control group
group that is not experimented on
provides a baseline for comparison
control
measures that are taken to reduce the influence of extraneous variables on the dataset
examples of control
homogenous sample
consistent data-collection procedures
manipulation of independent variable
randomization
types of research design
experimental
quasi-experimental (no randomization)
non-experimental
what type of research design is most common in nursing?
quasi-experimental
types of experiment designs
true or classic
solomon four group
after only
nonequivalent control group
after-only nonequivalent control group
one group pretest-posttest
time series
types of nonexperimental designs
correlational studies
developmental (cross-sectional, longitudinal/prospective, retrospective ex facto)
correlational study
examine relationship between 2+ variables
cross-sectional study
outcome among individuals at one point in time
longituindal/prospective
changes in individuals over time
retrospective/ex post facto
variable x is related to variable y, but x can’t be randomized or measured
find a group without x and compare to a group with x and see if there is a difference in y
threats to internal validity
history
maturation
testing
instrumentation
mortality
selection bias
threats to external validity
selection
reactive
measurement
3 characteristics of a good research question
well-defined population
well-defined variables
testability
3 types of research questions
correlational
comparative
experimental
directional hypothesis
hypothesis states a relationship exists and in what way the data will trend
non-directional hypothesis
hypothesis states a relationship exists but does not predict how the data will trend
descriptive statistics
summarize or describe features of the data set
re: central tendency or dispersion
not the actual results of the data itself
usually displayed in visuals (table, graph, histogram)
inferential statistics
make generalizations about the population based on sample statistics and hypothesis testing
p value
probability
represents how likely x is to happen
evaluates how well the data supports the null hypothesis
high p value
data supports null hypothesis
>0.5
low p value
data does not support null hypothesis
<0.5
confidence interval
value that sample is believed to lie within
normally measured at 95%
CI <95% considered not statistically significant
correlation coefficient
measures strength and direction of relationship between 2 variables
range of values for correlation coefficient
-1.0 - 1.0
-1.0 = strong negative (inverse) relationship
+1.0 = strong positive relationship
0.0 = no relationship