Should Dr. Rhodes be concerned about using this sampling method?
Yes, because his sample will not be representative of people in general
. Yes, because external validity is very important for the type of claim he is making.
What kind of sample is best for external validity?
— In terms of external validity, the best sample is
a representative sample
— one in which every member of the population has an equal chance of being selected.
What is a specific method that the professor could use to ensure that the participants in his study are representative of the population he is studying?
Stratified random sampling
ensures that each subgroup of a given population is adequately represented within the whole sample population of a research study.
Which type of sampling method produces a sample that is most likely to generalize to the population?
With nonprobability sampling, there is no way of estimating the probability of an element’s being included in a sample. If the researcher’s interest is in generalizing the findings derived from the sample to the general population, then
probability sampling
is far more useful and precise.
Is Dr Lawrence collecting a representative sample?
Lawrence collecting a representative sample? –
Yes
, because the sample includes a representative proportion of men and women.
What type of sampling is the easiest to do because of its convenience?
Convenience sampling
means collecting a sample of whichever participants are easiest to reach. It’s a first come, first serve sample. Quota Sampling. This method is similar to stratified sampling: the population is divided into groups, based on certain characteristics.
Which sampling method is unscientific and unreliable?
A legitimate poll uses scientific sampling to learn about the opinions and behaviors of a population.
Pseudo-polls
include unscientific (and thus, unreliable) attempts to measure opinions and behaviors as well as other practices that look like polls but are designed for purposes other than legitimate research.
What is the difference between internal and external validity?
Internal validity refers to the degree of confidence that the causal relationship being tested is trustworthy and not influenced by other factors or variables. External validity refers to the
extent to which results from a study can be applied
(generalized) to other situations, groups or events.
Which of the following would be a threat to external validity?
What are threats to external validity? There are seven threats to external validity:
selection bias, history, experimenter effect, Hawthorne effect, testing effect, aptitude-treatment and situation effect
.
What improves external validity?
How can we improve external validity? One way, based on the sampling model, suggests that
you do a good job of drawing a sample from a population
. … That is, your external validity (ability to generalize) will be stronger the more you replicate your study.
What is the best way of choosing a sample to statistically represent a population?
Your
sampling frame should include the whole population
. To conduct this type of sampling, you can use tools like random number generators or other techniques that are based entirely on chance. A sample is biased if individuals or groups from the population are not represented in the sample.
How do you determine if a sample is representative of the population?
A representative sample should be
an unbiased reflection of what the population is like
. There are many ways to evaluate representativeness—gender, age, socioeconomic status, profession, education, chronic illness, even personality or pet ownership.
What is the importance of knowing how do you choose your sample?
If each observation is selected randomly, then the sample
will naturally reflect the qualities of the population
. Thanks to this quality of probability, researchers are able to understand large populations by sampling small groups from the population.
What is the major difference between stratified sampling and quota sampling?
Stratified sampling uses simple random sampling when the categories are generated; sampling of the quota
uses sampling of availability
. For stratified sampling, a sampling frame is necessary, but not needed for quota sampling.
What makes a good sample population?
What makes a good sample? A good sample should be
a representative subset of the population we are interested in studying
, therefore, with each participant having equal chance of being randomly selected into the study.
What sample size is representative of the population?
A good maximum sample size is usually
around 10% of the population
, as long as this does not exceed 1000. For example, in a population of 5000, 10% would be 500. In a population of 200,000, 10% would be 20,000.
