112 câu trắc nghiệm Kinh tế lượng – Phần 1

4. Sampling

KTL_003_C4_1: In what of the following situations sampling plays an important role:
○ In identifying, developing, and understanding new marketing concepts that need to be investigated
○ In designing questionnaires
○ In reducing the time and money it will take to conduct a survey
○ In developing scale measurements used to collect primary data
● All of the above

KTL_003_C4_2: We use sampling many times during our daily lives.
● True
○ False

KTL_003_C4_3: The studies which cover all the members of ______________ are called ‘census’.
○ Elements
● Population
○ Sample
○ Sampling frame
○ All of the above

KTL_003_C4_4: A ___________________ is a representation of the elements of the target population.
○ Population
● Sampling frame
○ Sample
○ Element
○ All of the above

KTL_003_C4_5: Non-sampling errors represent any type of bias that is attributable to mistakes in either drawing a sample or demining the sample size.
○ True
● False

KTL_003_C4_6: Which of the following is a not a probability sampling technique
○ Systematic random sampling
○ Cluster sampling
● Quota sampling
○ Stratified sampling

KTL_003_C4_7: In which sampling technique a random number table is employed.
○ Snowball sampling
● Simple random sampling
○ Systematic random sampling
○ Convenience sampling
Sampling

KTL_003_C4_8: In which technique selection of sample is left entirely to the researcher.
● Convenience sampling
○ Simple random sampling
○ Stratified sampling
○ Cluster sampling

KTL_003_C4_9: Which nonprobability sampling technique is called as the most refined nonprobability technique?
○ Convenience sampling
○ Simple random sampling
○ Judgement sampling
○ Quota sampling
● Snowball sampling

KTL_003_C4_10: In which of the sampling techniques each sampling unit has a known, nonzero chance of selection.
● Probability sampling technique
○ Nonprobability sampling technique

KTL_003_C4_11: When determining the sample size what qualitative and quantitative issues should be taken into consideration by researcher?

The qualitative issues considered may include factors such as:
– Nature of research and expected outcome
– Importance of the decision to organization
– Number of variables being studied
– Sample size in similar studies
– Nature of analysis
– Resource constraints
Various quantitative measures are also considered when determining sample size such as:
– Variability of the population characteristics (greater the variability, larger the sample required)
– Level of confidence desired (higher the confidence desired, larger the sample required);
– Degree of precision desired in estimating population characteristics (more precise the study, larger the sample required).

KTL_003_C4_12: Provide a brief note highlighting major differences between probability and nonprobability sampling techniques?

Probability sampling is more robust in comparison as in this technique each sampling unit has a known, nonzero chance of getting selected in the final sample.

Nonprobability techniques on the other hand, do not use chance selection procedure. Rather, they rely on the personal judgement of the researcher. The results obtained by using probability sampling can be generalized to the target population within a specified margin of error through the use of statistical methods. Put simply, probability sampling allows researchers to judge the reliability and validity of the findings in comparison to the defined target population. In case of nonprobability sampling, the selection of each sampling unit is unknown and therefore, the potential error between the sample and target population cannot be computed. Thus, generalizability of findings generated through nonprobability sampling is limited. While probability sampling techniques are robust in comparison one of the major disadvantages of such techniques is the difficulty in obtaining a complete, current and accurate listing of target population elements.

KTL_003_C4_13: Discuss stratified sampling in details.

Stratified sampling is a probability sampling technique which is distinguished by the two-step procedure it involves. In the first step the population is divided into mutually exclusive and collectively exhaustive sub-populations, which are called strata. In the second step, a simple random sample of elements is chosen independently from each group or strata. This technique is used when there is considerable diversity among the population elements. The major aim of this technique is to reduce cost without lose in precision. There are two types of stratified random sampling; (a) proportionate stratified sampling and (b) disproportionate stratified sampling. In proportionate stratified sampling, the sample size from each stratum is dependent on that stratum’s size relative to the defined target population. Therefore, the larger strata are sampled more heavily using this method as they make up a larger percentage of the target population. On the other hand, in disproportionate stratified sampling, the sample selected from each stratum is independent of that stratum’s proportion of the total defined target population. There are several advantages of stratified sampling including the assurance of representativeness, comparison between strata and understanding of each stratum as well as its unique characteristics. One of the major difficulty however, is to identify the correct stratifying variable.

KTL_003_C4_14: Explain quota sampling and its advantages as well as disadvantages.

Quota sampling restricts the selection of the sample by controlling the number of respondents by one or more criterion. The restriction generally involves quotas regarding respondents’ demographic characteristics (e.g. age, race, income), specific attitudes (e.g. satisfaction level, quality consciousness), or specific behaviours (e.g. frequency of purchase, usage patterns). These quotas are assigned in a way that there remains similarity between quotas and populations with respect to the characteristics of interest. Quota sampling is also viewed as a two-stage restricted judgement sampling. In the first stage restricted categories are built as discussed above and in the second stage respondents are selected on the basis of convenience of judgement of the researcher. This procedure is used quite frequently in marketing research as it is easier to manage in comparison to stratified random or cluster sampling. Quota sampling is often called as the most refined form of nonprobability sampling. It also reduces or eliminates selection bias on the part of field workers which is strongly present in convenience sampling. However, being a nonprobability method it has disadvantages in terms of representativeness and generalizability of findings to a larger population.