• Survey Research
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• v.7 no.2
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• pp.39-52
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• 2006

Most of Korean survey institutions adopt quota sampling for telephone surveys based on region, gender and age-band. In weekdays, it is well blown that there exist substantial differences in day time in-house rate by individual's socio-demographic attributes. So, quota sampling may induce systematic respondent selection bias. To solve the problem, we propose "time-balanced quota sampling" in which interviewer's call time-band is added as an quota variable. Furthermore, we propose "time-balanced quasi-quota sampling" which is derived by partially relaxing evening time quotas in time-balanced quota sampling. We compare the conventional and the newly proposed quota sampling schemes by drawing Monte Carlo samples from the hypothetical population for which the Korea 2004 time use survey data is assumed.

• Survey Research
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• v.12 no.2
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• pp.77-88
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• 2011

Korean telephone surveys have been based on telephone directory and thus criticized for considerable under-coverage. Now, Korean survey institutions progress to random digit dialing (RDD) very actively. But still most surveys are administered by quota sampling, prone to assign heavier weights to social classes with more hours staying indoor. As a practical remedy, time-balanced quota sampling scheme was proposed by Huh and Hwang (2006). This study compares two telephone surveys on TV audience environment in Korea: RDD with conventional quota sampling versus RDD with time-balanced quota sampling.

• Asian Journal for Public Opinion Research
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• v.3 no.4
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• pp.156-175
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• 2016

This paper considers whether random sampling always produces more accurate survey results in the case of South Korea. We compare information from the 2010 census to the demographic variables of three public opinion surveys from South Korea: Gallup Korea's Omnibus Survey (Survey A) is conducted every two months by Gallup Korea; the annual Social Survey (Survey B) is conducted by Statistics Korea (KOSTAT); the Korean General Social Survey (KGSS or Survey C) is conducted annually by the Survey Research Center (SRC) at Sungkyunkwan University (SKKU). Survey A uses quota sampling after randomly selecting the neighborhood and initial addresses; Survey B uses random sampling, but allows replacements in some situations; Survey C uses simple random sampling. Data from more than one year was used for each survey. Our analysis suggests that Survey B is the most representative in most respects, and, in some respects, Survey A may be more representative than Survey C. Data from Survey C was the least stable in terms of representativeness by geographical area and age. Single-person households were underrepresented in both Surveys A and C, but the problem was more severe in Survey A. Four-person households and married persons were both over-represented in Survey A. Less educated people were under-represented in both Survey A and Survey C. There were differences in income level between Survey A and Survey C, but income data was not available for Survey B or the census, so it is difficult to ascertain which survey was more representative in this case.

• The Korean Journal of Applied Statistics
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• v.16 no.2
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• pp.247-259
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• 2003

In Korea, quota sampling is mainly adopted in telephone surveys, instead of random sampling which requires call-back procedure and random selection of respondent within households. The contact mode based on the se $x^{*}$age quotas is economically more advantageous and less time-consuming. However, it lacks theoretical ground for valid statistical inference, so that it is hardly accepted in academic circles despite of widely spread practice. Subsequently, survey theoreticians argued that random sampling-based telephone surveys should be tried. In response, Research & Research (R&R), a private research company in Seoul, executed atelephone survey by random sampling mode for the prediction of 2002 Ulsan City Mayor Election. The aim of this case study is to find out various effects of the call-back rule with random selection of respondents by statistically re-analyzing R&R’s Ulsan Survey Data.s by statistically re-analyzing R&R’s Ulsan Survey Data.

• Proceedings of the Korean Association for Survey Research Conference
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• 2006.06a
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• pp.117-124
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• 2006

• Journal of Engineering Education Research
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• v.11 no.4
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• pp.58-63
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• 2008

This thesis investigated way of employment, education course of a training school of electrical company. And student more than. Faced a human power demand in an education demand and a field rehearsal student demand and and analyzed it. The sample extraction used industrial classification, work of scale, Assignment sample extraction way (quota Sampling). All data called at a silver phone and, and the investigated, The data parser analyzed the statistics that used Microsoft Excel.

• Journal of Engineering Education Research
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• v.12 no.2
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• pp.89-95
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• 2009

This thesis investigated way of employment, education course of a training school of Programmable Logic Controller a Field. I inquired into a demand of an engineer and a necessary level of professional education. As a result, I have a purpose in what offer the information that cared for a beginning to work elevation and education training and boat development of a student more than. Faced a human power demand in an education demand and a field rehearsal student demand and analyzed it. The sample extraction used industrial classification, work of scale, Assignment sample extraction way (quota sampling). All data called at a silver phone and the investigated, The data parser analyzed the statistics that used Microsoft Excel.

• Journal of Engineering Education Research
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• v.11 no.3
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• pp.90-95
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• 2008

This thesis investigated way of employment, education course of a training school of electrical company. I inquired into a demand of an engineer and a necessary level of professional education. As a result, I have a purpose in what offer the information that cared for a beginning to work elevation and education training and boat development of a student more than. Faced a human power demand in an education demand and a field rehearsal student demand and analyzed it. The sample extraction used industrial classification, work of scale, Assignment sample extraction way (quota Sampling). All data called at a silver phone and the investigated, The data parser analyzed the statistics that used Microsoft Excel.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.375-385
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• 2009

For 2007 Korea presidential election, most polls by telephone surveys indicated Lee Myung-Bak led the second runner-up Jung Dong-Young by certain margin. The margin between two candidates can be estimated accurately by averaging individual poll results, provided there exists no systematic bias in telephone surveys. Most Korean telephone surveys via telephone directory are based on quota samples, with the region, the gender and the age-band as quota variables. Thus the surveys may result in certain systematic bias due to unbalanced factors inherent in quota sampling. The aim of this study is to answer the following questions by the analytic methods adopted in Huh et al. (2004): Question 1. Wasn't there systematic bias in estimates of support rates. Question 2. If yes, what was the source of the bias? To answer the questions, we collected eighteen surveys administered during the election campaign period and applied the iterated proportional weighting (the rim weighting) to the last eleven surveys to obtain the balance in five factors - region, gender, age, occupation and education level. We found that the support rate of Lee Myung-Bak was over-estimated consistently by 1.4%P and that of Jung Dong-Young was underestimated by 0.6%P, resulting in the over-estimation of the margin by 2.0%P. By investigating the Lee Myung-Bak bias with logistic regression models, we conclude that it originated from the under-representation of less educated class and/or the over-representation of house wives in telephone samples.

• Journal of Distribution Science
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• v.19 no.9
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• pp.41-52
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• 2021

Purpose: Virtual reality is a unique technology to distribute data and demonstrates user's understanding towards complex products. The objective of this research is to investigate the impact of virtual reality on real world purchase intention of automotive cutting tools in Thailand's exhibitions. Hence, the research framework was constructed by telepresence, perception narrative, authenticity, trustworthiness, functional value, aesthetics, and purchase intention. Research design, data and methodology: Samples were collected from 500 visitors who participated in the selected top two metalworking exhibitions. Mix sampling approach is applied by using non-probability sampling methods of purposive or judgmental sampling, quota sampling, and convenience sampling method, respectively to reach target samples. Confirmatory Factor Analysis (CFA) and Structural Equation Model (SEM) were used to analyze and confirm goodness-of-fit of the model and hypothesis testing. Results: The results indicate that authenticity, functional value, and trustworthiness induced higher experiential value towards purchase intention. Those variables are stimulated by telepresence and perception narrative towards VR experience. Conclusions: Consumer's purchase intention towards VR experience on engineering cutting tools rely on consumer's sense of authenticity, trustworthiness, and functional value. Hence, marketing practitioners in automotive companies are encouraged to develop VR which focusing on significant factors to enhance consumers purchase intention.