Week 6: Quantitative Research Flashcards
how do we create a representative group in quantitative research
sampling
what is a sampling plan?
how the subjects will be selected
how can researchers determine eligibility in a sample
inclusion criteria
what is a representative sample
is one whose characteristics closely approximate those of the population. Example: gender or age group.
what does inclusion criteria mean
are the defined attributes of a target population. Example: diagnosis, age group, practice constraints of convenience, people’s ability/interest to participate, research design considerations (i.e. placebo vs drug), presence of symptoms (i.e. migraine aura).
what are characteristics that a population of people must not possess
exclusion criteria
what are the two goals in sampling plan
representativeness and adequate size
what is a subpopulation within the overall population (1 or more characteristics)
strata
what type of sampling is accomplished over multiple stages
staged sampling
what is the systemic overrepresentation or underrepresentation of a population subgroup on a characteristic relevant to the research question
bias
what there is a difference between sample value and population value what is seen
sampling error
what is a probability sampling strategy
random selection of elements = ensures greater confidence in representativeness
what is non-probability sampling
sampling that uses selection of non-random methods
in what type of sampling is the sample selected based on the researchers judgement
non-probability sampling
in which type of sampling does everyone have an equal chance of being selected
probability
which type of sampling is bias more a concern
non-probability sampling
when might it be good idea to use non-probability sampling
Useful in environment that shares similar traits
which population sampling method is useful when researchers need to ensure accuracy
probability
which type of sample makes finding the target population simple
non- probability
list 3 reasons why probability sampling would be choose
When you want to reduce the sampling bias
When the population is usually diverse
To create an accurate sample
what are the 4 types f probability samples
- simple random sample
- stratified random sample
- cluster sample
- systemic sample
which type of probability sample is entirely random
simple random sampling
which type of probability sample assigns numbers to all the individuals
simple random sample
which type of sample involves dividing people into smaller homogenous groups that don’t usually overlap
stratified random sampling
which type of sampling involves subgroups being organized
stratified random sample
in which group sampling does subgroups are organized, and then a random sample is drawn from each group separately
stratified random sampling
in what type of probability sampling are broad groups rather then individuals selected
clusters
what is an example of cluster sampling
hospitals, universities, country, state or region. Then the researcher creates smaller subunits: family, city, school programs and departments.
when every 6th individual or 10th case is select, what type of probability sampling is this called
systemic sampling
what are the different types of non-probability sampling researchers can use?
- convince
- consecutive
- purposive
- quota
- snowball
what is convince sampling
recruit from the most conveniently available participants.
what is a downside of convince sampling
Downside is that those who participate may be atypical of the population on the study outcomes.
how does consecutive sampling work
recruiting all the people from an accessible population who meet the eligibility criteria over a specific time interval or for a specified sample size
what is the downside of purposive sampling
Downside is that the preconceived notions of a researcher can influence the results
what is quota sampling
a sample is selected using quotas for certain subgroups based on population proportions to increase the representativeness of the sample
what is non probability susceptible to
decreased rigor and quality judgements about research designs
when do quantitative studies use a power analysis
When you need to define an effect of an intervention on a specific group of people with a defined trait or condition that is under study.
what is a power analysis
a mathematical procedure used to estimate sample size requirements
After establishing your RQ and study outcome variable, you must determine an adequate sample size for the study, which often requires a ___
power analysis
what is a type 1 error
rejecting H0 when it is true
false positive
type 2 error is when ______
accepting the H0 when it is false
false negative
a false positive is also known as
type 1 error
a false negative is also known as ___
type 2 error
p< 0.001 =
very strong evidence against the null hypothesis
what drives the type 1 errors
significance level (a)
0.05
good evidence against null hypothesis
H0 =
there are no mean differences between groups
Ha=
there are mean differences between groups
how do researchers control type 1 errors
by setting α at a level they are comfortable with
how do researchers control type 2 errors
by setting power (1-β) at 80% or 20% risk of committing a Type II error
the higher the number of observations (or participants)
the higher the power of the statistical test.
a nurse who conducts a study of teenage risk-taking by recruiting students from a local youth organization is relying on
convince sampling
what type of sample: studied the relationship between smoking in the home and lung cancer worry and perceived risk. They recruited a sample of 515 homeowners in Kentucky. They used______ sampling to ensure that half of the sample had a smoker in the home and half did not.
quota
example of a homogeneous strata
gender
