• Survey Research
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• v.8 no.1
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• pp.31-54
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• 2007

This paper examined the electoral polling methodologies such as sampling method, sampling frame and the classification of the don't-know responses. Quota sampling method seemed to be one of the major factors for the declining trust in the poll results. We suggested that new procedures for random sampling as well as the bad number screening procedures for RDD selection of phone numbers need to be developed. Also we reviewed how the KBS used the polls in defining voters' agenda and in communicating the public agenda to the candidates. In Korea, rates for the polls were based mainly on the number of interviews completed. It seemed to keep the polling companies from tim new and more time-demanding polling methods. Also various utilization of the polls are limited by the tendency to keep the questionnaire short.

• Journal of the Korean Society for Library and Information Science
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• v.40 no.2
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• pp.217-242
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• 2006

This Study reviewed 86 research articles using inferential statistics published in 2001-2004 in 4 korean core journals in the field of library and information science. Sampling methods, response rates and nonresponse bias, reliability test, and inferential statistic techniques used in the articles were critically reviewed and analyzed. Nonprobability sampling was mostly used. Average response rate was 74.47%. Parametric statistics were mostly used. Some misunderstandings in using each inferential statistics, especially Reliability Test, Multiple Regression, Factor Analysis, MDS, etc. were reported in this study.

• Survey Research
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• v.5 no.2
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• pp.3-30
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• 2004

In Korea, bellwether voting places were selected for exit poll based on the past voting results. Sometimes, voting place stratification were used to improve the exit poll performance. The sampled voting places are intended to mirror the general voters of the entire electoral district. But few studies have been done as to which sampling method works better. This study compared the four sampling methods-bellwether voting place sampling method, random sampling method, stratified bellwether sampling method and systematic sampling from ordered voting places method. When we applied the four methods to the 2004 general election data, the systematic sampling from ordered voting places method outperformed the other three sampling method. Also, we found that the additional sampling of voting places over nine contribute little to the accuracy of the estimation.

• Journal of Educational Research in Mathematics
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• v.21 no.1
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• pp.17-32
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• 2011

This study investigated pre-service teachers' understanding of statistical sampling. The researchers categorized major topics related to sampling into representativeness of samples, sampling variability, and sampling distribution, and selected concepts connected to each topic. Findings on this study are as follows: Even though most of the pre-service teachers considered the random sampling bringing unbiased outcomes as a proper sampling method, only 64% of them recognized that sample is a quasi-proportional, small-scale version of population; Few pre-service teachers understood that more important is the size of sample, not the portion of sample to population, and half of them appreciated that the number of sampling has a powerful effect on drawing of reliable results than the size of sample; Few pre-service teachers understood that sampling distribute is irrelevant to the shape of population and has a symmetrical bell-shape.

• Electronics and Telecommunications Trends
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• v.8 no.1
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• pp.77-84
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• 1993

본 연구는 ‘90년과 ’91년에 수행한 면접 및 우편을 이용한 전화서비스 품질에 관한 사용자의 만족도 평가조사의 단점 및 미비점을 보완하기 위한 방법으로, 운영시스팀인 SLMOS 와 LCR을 이용하여 전화수리 및 전화가설공사가 완료된 이용자를 빠르게 파악하여, 군락표집 및 비례층화표집방법으로 피험자를 선정, 전화로 설문조사를 수행함으로써 신뢰성 및 타당성을 지닌 설문조사를 수행하였다. 이렇게 조사된 데이터를 CCITT가 MOS 측정에 대하여 권고한 지침에 의하여 분석하여, 이용자가 인내할 수 있는 최저 품질의 한계치를 구해보았다. 이러한 방법을 이용하면 전화서비스품질의 기준값 작성이 가능하리라 본다.

• 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.

• Journal of The Korean Association For Science Education
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• v.6 no.2
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• pp.53-62
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• 1986

본 연구의 목적은 한국 중 고등학교 학생들의 지적 발달의 특성을 조사 분석함으로써 교과서 및 교육과정의 개발에 필요한 기초자료를 얻으려는 것이다. 지역, 학년, 연령, 성 및 가정의 사회 경제적 지위에 따른 인지 발달 특성을 조사하였다. 연구의 대상은 전국을 대도시, 중 소도시, 농촌으로 유층화한 유층군집 표집방법에 의해 표집한 중학교 1학년부터 고등학교 2학년까지의 남 녀 학생이었다. 표집학생 수는 중학교가 18개교 54학급 3,164명이었고, 고등학교가 18개교 36학급 1,981명이었다. 가정의 사회 경제적 지위는 가정의 경제적 형편, 부의 직업, 부의 학력, 가정의 수입 정도를 고려하여 4계층으로 구분하였다. 사용된 도구는 지적 영역의 조사에 Piaget의 인지발달이론에 따른 논리발달 검사를 이용했다. 분석된 결과를 요약하면 다음과 같다. 첫째, 명제논리, 확률논리, 조합논리, 변인조작개념은 연령과 학년이 높아질수록, 대도시로 갈수록, 사회 경제적 지위가 높을수록 더욱 발달하는 경향이다. 둘째, 개념의 발달경향에 있어서 이원추리와 조합논리개념의 발달이 확률논리와 명제논리 개념의 발달보다 빠른 경향이다. 셋째, 한국의 중등학생 중에서 12세의 64.6%, 13세의 58.1%, 14세의 43.8%, 15세의 30.1%, 16세의 22.6%가 구체적 조작 후기에 도달해 있다. 넷째, 중등학생의 학년별 인지발달경향을 보면 중1의 69.8%, 중2의 51.1%, 중3의 47.4%, 고1의 21.6%, 고2의 21.7%가 구체적 후기의 발달수준이다.

• Proceedings of the KSRS Conference
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• 2009.03a
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• pp.22-25
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• 2009

본 논문은 기 구축된 환경부의 중분류 토지피복도를 올해 KOMPSAT-2 화상으로 갱신하기 위한 예비연구에서 분류결과의 정확도 평가를 중점적으로 나타낸다. KOMPSAT-2 화상기반의 중분류 토지피복도는 객체지향의 분류기법을 이용하였고, 경계선 수정의 경우 반자동 기법에 의해 제작되었다. 계통표집과 임의표집에 의한 Kappa 분석에서 계통 표집의 KHAT값은 0.81, 임의표집의 KHAT값은 0.89를 각각 가지므로 거의 완벽의 일치성을 표시한다. 따라서 전술한 지도화 방법을 통해 제작된 KOMPSAT-2 화상의 중분류 토지피복도는 이용자에게 토지피복정보의 신뢰성도 함께 제공한다.

• Journal of the Korean Data and Information Science Society
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• v.20 no.6
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• pp.1103-1118
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• 2009

When we wish to estimate the mean or total of a finite population, the numbering of the population units is of importance. In this paper, we have proposed two methods for estimating the mean or total of a population having a linear trend, for the case when the reciprocal of the sampling fraction is an even number and the sample size is an odd number. The first method involves drawing a sample by using a method which is a generalization of Singh et al's (1968) modified systematic sampling, and using interpolation in determining the estimator. The second method involves selecting a sample by modified systematic sampling, and estimating the population parameters by the regression estimation method. Under the criterion of the expected mean square error based on Cochran's (1946) infinite superpopulation model, the proposed methods have been compared with existing methods. We have also made a comparison between the two proposed methods.

• Journal of Engineering Education Research
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• v.10 no.2
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• pp.19-43
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• 2007

The Korean Society for Engineering Education (KSEE) was founded in 1994, and the Journal of Engineering Education Research has published since 1998. The purpose of the study was to analyze the research methodologies and contents for all 126 papers which were published from 1998 to 2005. A statistical package SPSS(ver. 15.0) was used to analyze the coding data of all papers. The research contents were as follows: (1) A classification of the number of papers published according to year and researcher features (gender, institution, major field, number of authors, etc) was performed, (2) The analysis of research methodologies and contents of the papers published was performed, (3) Strategies to improve the quality of the journal were suggested by discussion from the analysis results. The results showed that the development research method was used most frequently, most papers were mode by major scholars of electrical and electronic engineering and scholars of Yonsei University made the most papers. In order to use the survey research method, the sampling methods were mainly used by total number, purposive, convenience, stratified sampling method, etc, questionnaire was used of 89.5%, descriptive statistics of frequency/% was used of 50%. To conduct the experimental research method, the models of nonequivalent groups posttest-only design and one-group pretest-posttest design were adopted, respectively. Finally, research strategies and new direction for improving the engineering education journal's papers at the section of discussion and suggestion were suggested.