N 580- Week 7 sampling
( chapter 12 & 13 )sampling &
Legal and ethical issues.
Questions and Complete
Solutions Graded A+
why do we sample ? - Answer: we sample because we need to get the representative sample of the
population.
why do we need inclusion and exclusion criteria in research? - Answer: -It is used to define attributes
that restrict the population to a homogeneous group of subjects.
-The inclusion criteria, as the sample should be congruent.
-it is also to control the extraneous variable bias, that would limit the strength of evidence.
- Both may have potential contaminating effect on the dependent variable
-This will increase the studies precision and strength of evidence , there by contributing to the accuracy
and generalization of the study.
recap - Answer: define the target population
determine the sampling frame
select the sampling technique
determine the sample size
execute the sampling process
Population - Answer: A population is a well-defined set that has specified properties and can be
composed of people, animals, objects, or events.
Target populations - Answer: target population is established via criteria (including inclusions and
exclusions), and is composed of the entire set of cases about which the research team would like to
make generalizations.
, sampling - Answer: Sampling is the process of selecting a representative subset of the targeted
population.
Sampling strategies are generally grouped into two categories: non-probability sampling (nonrandom
methods) and probability sampling (random selection)
Non-probability sampling
-convenience sampling ( weakest)
-quata sampling
-Purposeive sampling /judgement sampling - Answer: Non-probability sampling results are less
generalization due to the lack of randomization; thereby producing fewer representative samples.
used for exploratory research / hypothesis generation
-convenience sampling
-quata sampling
-Purposeive sampling /judgement sampling
-snowball sampling - Answer: 1. Convenience sample; use of most readily accessible sampling ( you want
to do a TB study and get the samples from the TB clinic)
2.**quota sampling: A quota sample identifies the strata and of the population and proportionately
represent the strata in the population. ( A- 2000( 30%), B- 1000( 20 % ) etc)
Advantage: It may be a representative sample but other characters may not be representative/
generalization will be an issue.
3. purposeful /judgement sample: Units are samples based on professional judgement
3.Snowball sampling ;
One member of the sample identify the other . like if you do a study on homless, one identified the
other.
** people you do not like may not be referred
( chapter 12 & 13 )sampling &
Legal and ethical issues.
Questions and Complete
Solutions Graded A+
why do we sample ? - Answer: we sample because we need to get the representative sample of the
population.
why do we need inclusion and exclusion criteria in research? - Answer: -It is used to define attributes
that restrict the population to a homogeneous group of subjects.
-The inclusion criteria, as the sample should be congruent.
-it is also to control the extraneous variable bias, that would limit the strength of evidence.
- Both may have potential contaminating effect on the dependent variable
-This will increase the studies precision and strength of evidence , there by contributing to the accuracy
and generalization of the study.
recap - Answer: define the target population
determine the sampling frame
select the sampling technique
determine the sample size
execute the sampling process
Population - Answer: A population is a well-defined set that has specified properties and can be
composed of people, animals, objects, or events.
Target populations - Answer: target population is established via criteria (including inclusions and
exclusions), and is composed of the entire set of cases about which the research team would like to
make generalizations.
, sampling - Answer: Sampling is the process of selecting a representative subset of the targeted
population.
Sampling strategies are generally grouped into two categories: non-probability sampling (nonrandom
methods) and probability sampling (random selection)
Non-probability sampling
-convenience sampling ( weakest)
-quata sampling
-Purposeive sampling /judgement sampling - Answer: Non-probability sampling results are less
generalization due to the lack of randomization; thereby producing fewer representative samples.
used for exploratory research / hypothesis generation
-convenience sampling
-quata sampling
-Purposeive sampling /judgement sampling
-snowball sampling - Answer: 1. Convenience sample; use of most readily accessible sampling ( you want
to do a TB study and get the samples from the TB clinic)
2.**quota sampling: A quota sample identifies the strata and of the population and proportionately
represent the strata in the population. ( A- 2000( 30%), B- 1000( 20 % ) etc)
Advantage: It may be a representative sample but other characters may not be representative/
generalization will be an issue.
3. purposeful /judgement sample: Units are samples based on professional judgement
3.Snowball sampling ;
One member of the sample identify the other . like if you do a study on homless, one identified the
other.
** people you do not like may not be referred
