Question 1

If the researcher is expecting different responses between males and females in a study,which type of sample might be most useful?

Accepted Answer

A stratified random sample would be the most useful because it involves dividing the population into subgroups based on a certain characteristic (in this case, gender) and then randomly selecting participants from each subgroup. This ensures that the sample is representative of the population and allows for comparisons between the male and female groups.

Question 2

Which of the following sampling methods,if properly invoked,will produce projectable results?

Accepted Answer

C

Question 3

Which of the following sampling methods is the most statistically efficient (the most representative)?

Accepted Answer

Stratified random sampling is the most statistically efficient method because it ensures representation from all subgroups within the population. This is achieved by dividing the population into homogeneous subgroups (strata) based on a certain characteristic and randomly selecting a sample from each stratum. This reduces the sampling error and increases the precision of the estimate compared to other methods. Simple random sampling, systematic random sampling, and cluster sampling can all lead to biased or less representative samples if not done properly. Therefore, stratified random sampling is the best choice for obtaining the most accurate and representative sample.

Question 4

A researcher randomly selected 10 census tracts from a metropolitan area.Within each census tract,30 households were randomly selected.The sampling technique just described would be a ______________.

Accepted Answer

The described sampling technique is a cluster sampling method, specifically an area cluster, because entire census tracts (clusters) were randomly selected, and then within those tracts, households were sampled. This approach does not involve stratification by characteristics or systematic selection based on a list or sequence, distinguishing it from the other options.

Question 5

Stratified random samples are often confused with which of the following nonprobability sampling techniques?

Accepted Answer

Quota sampling also involves dividing the population into subgroups, but unlike stratified random sampling, the proportions of subgroups in the sample are not necessarily representative of the population. Instead, researchers use quotas to ensure that they include a certain number of participants from each subgroup, regardless of whether that subgroup is proportionally represented in the population. This can lead to bias in the sample selection process.

Question 6

The type of error which results from the fact that samples are not perfectly representative of the populations from which they are drawn is known as _______.

Accepted Answer

Sampling error results from the fact that samples are not perfectly representative of the populations from which they are drawn. Measurement error refers to errors in the actual measurement process. Systematic error results from consistent and predictable deviations from the true value. Nonsampling error refers to all other sources of error in a study, such as errors in data entry or processing. Selection error refers specifically to errors that arise from the process of selecting participants for a study, such as when the sample is not truly random.

Question 7

All other things equal,larger samples will have less ___________ than smaller samples.

Accepted Answer

Sampling error refers to the discrepancy that may occur between a sample and the population it represents. As sample size increases, the sample becomes more representative of the population, and therefore, the sampling error decreases.

Question 8

Which of the following sample types is often used as a substitute for simple random sampling?

Accepted Answer

Systematic sampling is often used as a substitute for simple random sampling because it involves selecting every nth item from a list, which can approximate the randomness of simple random sampling while being easier to implement.

Question 9

In order to compute a skip interval,the researcher needs to know the desired sample size and the __________.

Accepted Answer

The skip interval formula involves dividing the population size by the desired sample size, thus the researcher needs to know the population size to be able to calculate the skip interval.

Question 10

What do convenience,judgment,quota,and snowball samples have in common?

Accepted Answer

Convenience, judgment, quota, and snowball samples are all types of nonprobability samples. This means that they do not involve random selection of participants from a population, which can limit their representativeness and generalizability. However, they can still be useful in certain situations where probability sampling is not feasible or practical.

Question 11

The first step in the development of a sampling plan is to:

Accepted Answer

Defining the population of interest is the first step in developing a sampling plan because it is necessary to know who or what will be the focus of the study before deciding how to select a sample and what methods to use for data collection and analysis.

Question 12

Which of the following could serve as the basis for forming a stratum?

Accepted Answer

A stratum can be based on various factors such as usage rate, gender, and income level. Therefore, all of the options (A, B, and C) could serve as the basis for forming a stratum.

Question 13

The _____________ is a list of the members or elements from which units to be sampled are selected.

Accepted Answer

The sample frame is a list of the members or elements from which units to be sampled are selected. The population refers to the entire group of individuals or elements from which the sample is drawn. The sample source is the method or location from which the sample is obtained, while the universe is a broader term that can refer to all existing matter or a hypothetical concept. Therefore, the sample frame is the best option for describing the list of members or elements from which units to be sampled are selected.

Question 14

Which of the following types of samples enables the researcher to compute sampling error?

Accepted Answer

Probability samples are the only type of samples that allow for the calculation of sampling error. This is because probability samples are selected using a random method, which enables the researcher to make inferences about the population from the sample. Nonprobability and convenience samples do not involve random selection, so it is impossible to calculate sampling error. Therefore, only probability samples enable the researcher to compute sampling error.

Question 15

Under what kind of sampling procedure must the researcher adhere closely to precise selection procedures to ensure that the results are projectable to the population under study?

Accepted Answer

Probability sampling procedures involve random selection methods, which aim to ensure that every member of the population has an equal chance of being included in the sample. Thus, the results obtained from a probability sample can be generalized to the population with a known level of precision. However, to achieve this goal, the researcher must adhere strictly to the selection procedures to avoid bias and other sources of error that may compromise the representativeness of the sample. In contrast, nonprobability and non-random sampling procedures may not offer such guarantees and may be subject to various forms of selection bias and other limitations, which can affect the generalizability of the findings.

Question 16

Which of the following sampling techniques would give the researcher the most confidence in projecting the findings to the overall population?

Accepted Answer

Simple random sampling gives the researcher the most confidence in projecting the findings to the overall population as it ensures that every member of the population has an equal chance of being included in the sample. This eliminates any potential bias in the selection process and allows for generalizability of the findings to the entire population.

Question 17

________________ samples must be selected in such a way that every element of the population has a known and equal chance of being selected.

Accepted Answer

Simple random sampling ensures that every element in the population has an equal and known chance of being selected, making it the best choice for unbiased sampling.

Question 18

Which of the following is a correct statement regarding probability samples?

Accepted Answer

Option A is correct because probability sampling ensures that every member of the population has an equal chance of being included in the sample, thus providing a representative cross-section of the population.

Option B is correct because sampling errors can be estimated by using statistical methods, such as confidence intervals and margin of error.

Option C is correct because probability sampling enables researchers to make statistical inferences about the population from the sample data, thus allowing for accurate projections.

Therefore, all of the above statements are correct, and option D is the correct answer.

Question 19

The difference between the sample result and population value is known as __________.

Accepted Answer

The answer of The difference between the sample result and...

Question 20

_____________ is the total group of people from whom information is obtained.

Accepted Answer

The population of interest represents the total group of people from whom information will be gathered. The other choices are not as accurate; a sample refers to a portion of the population, a census is a complete count of everyone in the population, a subset is a smaller portion of the population, and the entire universe may not be relevant to the study.

Quiz 13: A: Basic Sampling Issues