Exam 2 Flashcards
experimental research design
- used for the purpose of examining causality
- researchers actively manipulate the independent variable to determine its effect on the dependent variable
- involve randomization and control groups
nonexperimental research design
-used for the purpose of describing a phenomenon in detail, explaining relationships and differences among variables, and predicting relationships and differences among variables
causality
relationship between a cause and its effect
probability
likelihood or chance that an event will occur in a situation
control
ability to manipulate, regulate, or statistically adjust for the multitude of factors that can influence the dependent variable
extraneous variables
factors that interfere with the relationship between the independent and dependent variables; confounding variable; Z variable
bias
extraneous variables influence the relationship btwn the independent and dependent variables
randomization
the selection, assignment, or arrangement of elements by chance
random sampling
technique for selecting elements whereby each has the same chance of being selected
random assignment
assignment technique in which subjects have an equal chance of being in either the treatment or the control group
between-groups design
study design where two groups of subjects can be compared
within-groups design
comparisons are made about the same subjects at two or more points in time or on two or more measures
study validity
ability to accept results as logical, reasonable, and justifiable based on the evidence presented
internal validity
degree to which one can conclude that the independent variable produced changes in the dependent variable
selection bias
- threat to internal validity that occurs when the change in the DV is a result of differences in the characteristics of subjects before they entered a study rather than a result of the IV
- can be minimized somewhat by the use of random assignment to groups
threats
forces that can change the result of a study
history
- threat to internal validity
- occurs when the DV may have been influenced by some event other than the IV that occurred during the course of the study
maturation
- threat to internal validity
- when subects change by growing or maturing
testing
- threat to internal validity
- when a pretest influences the way subjects respond to a post test
instrumentation
- threat to internal validity
- when there are inconsistencies in data collection
mortality
- threat to internal validity
- when there is a loss of subjects before the study is completed; attrition rate
attrition rate
dropout rate; loss of subjects before the study is completed
statistical conclusion validity
the degree that the results of the statistical analysis reflect the true relationship among the independent and dependent variables
type II error
when researchers inaccurately conclude that there is no relationship among the independent and dependent variables when an actual relationship does exist; when the researcher accepts the null when it should have been rejected
external validity
the degree to which the results of a study can be generalized to other subjects, settings, and times
construct validity
- threat to external validity
- when the instrument does not accurately measure the theoretical concepts
confounding
- threat associated with construct validity
- means there is a possible error in interpretation of the results
- occurs when experiemental controls do not allow the researcher to eliminate possible alternative explanations for the relationship between the IV and the DV
reactivity
the influence of participating in a study on the responses of subjects; hawthorne effect
hawthorne effect
subject’s behaviors may be affected by personal values or desires to please the experimenter; reactivity
effects of selection
threats to external validity when the sample does not represent the popluation
interaction of treatment with selection of subjects
- threat to external validity
- the independent variable might not affect individuals the same way
interaction of treatment and setting
- threat to external validity
- an intervention conducted in one setting cannot be generalized to a different setting
interactions of treatment and history
- threat to external validity
- historical events affect the intervention
retrospective designs
research designs when researchers look back in time to determine possible causative factors; ex post facto
ex post facto
research design in which researchers look back in time to determine causative factors; retrospective design
case-control
retrospective study in which researchers begin with a group of people who already had the disease; studies that compare two groups: those who have a specific condition and those who do not have the condition
cross-sectional
nonexperiemental design used to gather data from a group of subjects at only one point in time; study design to measure exposure and disease as each exists in a population or representative sample at one specific point in time
cohort comparison
nonexperimental cross-sectional design in which more than one group is studied at the same time so that conclusions about a variable over time can be drawn without spending as much time
longitudinal designs
designs used to gather data about subjects at more than one point in time
prospective designs
studies over time with presumed causes that follow subjects to determine whether the hypothesized effects actually occur
panel designs
longitudinal design were the same subjects, drawn from the general population, provide data at multiple points in time
trend
longitudinal design to gather data from different samples across time
follow-up
longitudinal design used to follow subjects, selected for a specific characteristic or condition, into the future
crossover design
experimental designs that use two or more treatments; subjects receive treatments in random order
questionaires
printed instruments used to gather numerical data
scales
used to assign a numeric value or score a continuum
Likert scales
ordinal-level scales containing seven points on an agree or disagree continuum
visual analog scale
ratio-level scale of a 100-mm line anchored on each end with words or symbols (FACES)
physiological measures
data obtained from biological, chemical, and microbiological phenomena
nominal
lowest level of measurement whereby data are categorized simply into groupes; categorical data
ordinal
continuum of numerical values where the intervals are meant to be equal
interval
continuum of numeric values with equal intervals that lacks an absolute zero value
measurement error
difference btwn the true store and the observed score
random error
error that occurs by chance during measurement
systematic error
error that occurs in the same way with each measurement
methodological
studies for the purpose of creating and testing new instruments
psychometrics
development of instruments to measure psychological attributes
validity
the degree that an instrument measures what it is supposed to meausure
population
the entire group of elements that meet study inclusion criteria
elements
basic unit of the population such as individuals, events experiences, or behaviors
subjects
individuals who participate in studies, typically studies using a quantitative design
sampling plan
plan to determine how the sample will be selected and recruited
sample
a select group of subjects that is representative of all eligible subjects
target population
all elements that meet the study inclusion criteria
accessible population
the group of elements to which the researcher has reasonable access
representativeness
the degree to which elements of the sample are like elements in the population
inclusion criteria
characteristics that each element must possess to be included in the sample
exclusion criteria
characteristics of elements that will not be included in the sample
sampling error
error resulting when elements in the sample do not adequately represent the population
sampling bias
a threat to external validity when a sample includes elements that over- or underrepresent characteristics when comparaed to elements in the target population
probability sampling
sampling method in which elements in the accessible population have an equal chance of being selected for inclusion in the study
sampling frame
a list of all possible elements in the accessible population
simple random sampling
randomly selecting elements from the accessible population
stratified random sampling
selecting elements from an accessible population that has been divided into groups or strata
cluster sampling
random sampling method of selecting elements from larger to smaller subsets of an accessible population; multistaging sampling
systematic random sampling
sampling method in which every k-th element is selected from a numbered list of all elements in the accessible population; the starting point on the list is randomly selected
sampling interval
the interval (k) between each element selected when using systematic random sampling
nonprobability sampling
sampling methods that do not require random selection of elements
convenience sampling
nonprobability sampling method in which elements are selected because they are easy to access
quota sampling
nonprobability sampling method used in qualitative studies to select a distinct group of individuals who either have lived the experience or have expertise in the event or experience being studied; sampling method to recruit specific persons who could provide inside information
snowball sampling
recruitment of participants based on word of mouth or referrals from other participants
network sampling
recruitment of participants based on word of mouth from other participants; snowball sampling
theoretical sampling
nonprobability sampling method used in grounded theory to collect data from an initial group of participants
homogenicity
the degree to which elements are similar or homogeneous
heterogeneous
the degree to which elements are diverse or not alike
attrition rate
dropout rate; loss of subjects before a study is completed; threat of mortality
power analysis
a statistical method to determine the acceptable sample size that will best detect the true effect of the independent variable
significance level
the alpha level established before the beginning of a study
effect size
estimate of how large a difference will be observed between the groups
data saturation
in qualitative research, the time when no new information is being obtained and repetition of information is consistently heard
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
anonymity
keeping the names of subjects separate from data so that no one, not even the researcher, knows the subjects’ identities
confidentiality
the protection of the subjects identity from everyone except the researcher
informed consent
ethical practice requiring researchers to obtain voluntary participation by subjects after subjects have been informed of possible risks and benefits
coercion
the threat of harm or the offer of an excessive reward with the intend to force an individual to participate in a research study
assent
permission given by children to participate in research
meta-analysis
a scholarly paper that combines results of studies, both published and unpublished, into a measurable format and statistically estimates the effects of proposed interventions
practice guidelines
systematically developed statements to assist healthcare providers with making appropriate decisions about health care for specific clinical circumstances
statistics
- the branch of mathematics that collects, analyzes, interprets, and presents numerical data in terms of samples and populations
- the numerical outcomes and probabilities derived from calculations on raw data
descriptive statistics
collection and presentation of data that explain characteristics of variables found in the sample
inferential statistics
analysis of data as the basis for prediction related to the phenomenon of interest
population parameters
characteristics of a population that are inferred from characteristics of a sample
sample characteristics
numerical data describing characteristics of the sample
univariate analysis
the use of statistical tests to provide information about one variable
bivariate analysis
the use of statistics to describe the relationship between two variables
multivariate analysis
the use of statistics to describe the relationships among three or more variables
