62 terms

WGU
Pgs 63 to 68
Sampling (1, 2 of 2)

Two steps to producing data are _____ and ______.

sampling and study design

It is essential that the _______ be truly representative of the largest population

sample

The _____ for producing data must be considered carefully.

design

Studies should be designed to discover what we wan to know about the variables of interest for individuals in the ________.

sample

Association does ________ imply causation.

NOT

A sample that produces data that is not representative because of the systematic under- or over-estimations of the values of the variable of interest is called _____.

bias

_______ may result from either a poor sampling plan or from poor design for evaluation the variable of interest.

Bias

________ sample is where individuals have selected (volunteered) themselves to be included in the study.

Volunteer

A ________ sample is almost guaranteed to be biased because volunteers tend to be comprised of individual who have a particularly strong opinion about and issue and are looking for an opportunity to voice it.

volunteer

Data obtained from a ________ response sample is quite useless since the sampled individuals only provide information about themselves and we cannot generalize to any larger group at all.

voluntary

________ samples are sometimes the only ethical way to obtain a sample, example medical studies.

Volunteer

A _______ sample is where individuals happen to be at the right time and place to suit the schedule of the researcher.

convenience

Posting a music lover's survey on a university internet bulletin board and asking students to vote for their favorite type is called a ________ sample.

volunteer

Standing outside the student union and asking students passing by to respond to your questions about music preference is a _______ sample.

convenience

Depending on what ______ is being studied, it may be that a convenience sample provides a fairly representative group.

variable

A convenience sample may also be susceptible to _____ because certain types of individuals are more likely to be selected than others. In the extreme, some convenience samples are designed in such a way that certain individuals have no chance at all of being selected.

bias

Ask your professors for email rosters of all the students in your classes. Randomly sample some addresses, and email those students with your question about musical preference is an example of ________.

sampling frame

_________ lists potential individuals to be samples and does not match the populations of interest.

Sampling frame

Sampling frame can be _____ because the population of interest consists of only one type of person. It is always best to have the sampling frame match the population as closely as possible.

bias

Obtain a student directory with email addresses of all the university's students, and send the music poll to every 50th name on the list is an example of _______ sampling.

systematic

________ sampling may not or may be subject to any clear bias.

Systematic

The safest route with no bias is _______ sampling.

Random

______ sampling is when individuals are sampled completely at random, and without replacement, then each group of a given size is just as likely to be selected as all the other groups of that size.

simple random sample (SRS)

Obtain a student directory with email addresses of all the university's students, and send your music poll to a sistudents is an example of ________.

simple random sample (SRS)

As long as all of the students respond, then the sample is not subject to any _____ and should succeed in being representative of the population of interest.

bias

In an SRS (simple random sample), what if only 40% of people sent back their votes?

The results of this poll would not necessarily be representative of the population, because of the potential problems associated with volunteer response and no response.

A simple random sample is the _______ way to base a selection on randomness.

easiest

What are the 3 most common types of sampling plans?

SRS (simple random sampling), Cluster sampling, stratified sampling

______ is the simplest probability sampling plan, it is equivalent to selecting random names out of a hat, where each individual has the same chance of being selected.

Simple random sampling (SRS)

_______ is sampling technique is used when our population is naturally divided into groups.

Cluster sampling

In ________ sampling, we take a random sample of clusters, and use all the individuals within the selected clusters as our sample.

cluster

In order to get a sample of high-school seniors from a certain city, you choose 3 high schools at random from among all the high schools in that city, and use all the high school seniors in the three selected high schools as your sample, this is an example of _______ sampling

cluster

When our population is naturally divided into groups, the are called _______.

clusters

________ sampling is used when our population is naturally divided into sub-populations.

Stratified

When our population is naturally divided into sub-populations we called it _______.

stratum (strata, plural)

All the students in a certain college are divided by gender or by year in college; all the registered voters in a certain city are divided by race are examples of ______ samples.

stratified

In _______ sampling, we choose a simple random sample from each stratum, and our sample consists of all these simple random samples put together.

stratified

Iin order to get a random sample of high-school seniors from a certain city, we choose a random sample of 25 seniors from each of the high schools in that city. Our sample consists of all these samples put together. This is called a ______ sample.

Stratified

SRS is OR is not subject to any bias.

IS NOT

Cluster sampling is OR is not subject to any bias.

IS NOT

Stratified sampling is OR is not subject to any bias.

IS NOT

In ______ sampling, we take a random sample of whole groups of individuals.

cluster

In ______ sampling, we take a simple random sample (SRS) of each group.

stratified

______ sampling is a complex form of cluster sampling.

Multistage

_______ refers to individuals who do not go along with the researchers' intention to include them in a study.

Nonresponse

If there are too many nonrespondents, and they are different from respondents in an important way, the same may be _____.

biased

_______ sampling makes the sampling process more manageable by working down from a large population to successively smaller groups within the population, taking advantage of stratifying along the way, and sometimes finishing up with a cluster sample or a simple random sample.

Multistage

A _______ sampling plan (such as a simple random sample, cluster, or stratified sampling) will result in a nonbiased sample, which can be safely used to make inferences

probability

______ is the science of collecting,organizing, summarizing, and analyzing information to draw conclusions or answer questions; it allows a measure of confidence in any conclusion.

Statistics

The entire group of individuals to be studied is called a ______.

population

An _____ is a person/object that is a member of the population to be studied.

individual

A ____ is a subset of the population to be studied.

sample

_______ is a numerical summary of a sample.

Statistics

________ statistics consists of organizing and summarizing data.

Descriptive

_______ statistics describe data through numerical summaries, table, and graphs.

Descriptive

A ______ is a numerical summary of a population.

parameter

________ statistics uses methods that take a result from a sample, extend it to the population, and measures the reliability of the result.

inferential

What are the 4 steps in the process of statistics?

Identify the research objective, collect the data needed to answer the question posed, describe the data, perform inference

Every kth is an example of sampling.

systematic

______ determines the accuracy of the predictions we make based on the surveys.

Sample size

The ______ the sample size, the more accurate the survey.

larger

We must consider ______ and _____ issues when increasing our sample size.

logistical and cost