• Title/Summary/Keyword: sample representativeness

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From Reflection to Self-assessment: Methods of Developing Critical Thinking in Students

  • Olha I. Dienichieva;Maryna I. Komogorova;Svitlana F. Lukianchuk;Liudmyla I. Teletska;Inna M. Yankovska
    • International Journal of Computer Science & Network Security
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    • v.24 no.7
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    • pp.148-156
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    • 2024
  • The research paper presents the results of an experimental research of the development of critical thinking in third-year students majoring in 013 "Primary Education" in studying a special course "From Reflection to Self-Assessment: Critical Thinking Skills" (based on Lauren Starkey methodology). The research was conducted during the first half of 2019-2020 academic year. The sample representativeness was ensured by the method of random selection, the strategy of randomization according to the criteria of age, gender, level of academic performance was described. Given the confidence interval p=95% and the confidence interval of the error Δ=±0.05, the sample size was 94 people, including of the experimental group and 49 students of the control group. The peculiarities of the development of such critical thinking skills as reflective thinking, self-analysis, awareness of one's own achievements and shortcomings, choice of problem-solving strategy, use of cognitive models of learning are revealed. It was found that the development of critical thinking was achieved through a comprehensive combination of self-assessment and reflection, performing exercises to develop the ability to clearly articulate the problem, find, analyse and interpret relevant information, draw the right conclusions and explanations.

Duration to First Job of Korean Young Graduates: Before and After the Economic Crisis (청년층의 첫 일자리 진입 : 경제위기 전후의 비교)

  • Ahn, Joyup;Hong, Seo Yeon
    • Journal of Labour Economics
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    • v.25 no.1
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    • pp.47-74
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    • 2002
  • Since the Economic Crisis at the end of 1997, unemployment rate soared up to the record-high 8.6% (February 1999) and, for youth aged 15~29, it was 14.6% (27.8% for aged 15~19). In spite of economic recovery after the crisis, new participants in labor market at the school-to-work transition have faced with difficulties in finding their first jobs and, even further, the ratio of youth at out-of the labor force but not in school has remained at a higher level. It is important to calibrate the negative effects of nonemployment in the short-run as well as in the long-run, but there has been few study on the school-to-work transition in Korea. This study focus on the nonemployment duration to first job after formal education and comparison of its pattern before and after the crisis. A proportional hazard model, considering job prenaration before graduation (21.4% of the sample), with the semi-parametric baseline hazard is applied to the sample from the Korean Labor and Income Panel Survey(1998~2000) and its Youth Supplemental survey(2000). Interview of the Survey is conducted, by the Korea Labor Institute, to the same 5,000 household and 13,738 individual sample, guaranteeing nationwide representativeness. The Supplemental Survey consists of 3,302 young individuals aged 15 to 29 at the time of survey and 1,615 of them who are not in school and provide appropriate information is used for the analysis. The empirical results show that there exists negative duration dependence at the first three or for months at the transition period and no duration dependence since a turning point of the baseline hazard rate and that unemployment rate reflecting labor demand conditions has a positive effect on exiting the nonemployment state, which is inconsistent with a theoretical conclusion. Estimation with samples separated by the date of graduation before and after the crisis shows that the effect of unemployment rate on the hazard was negative for the pre-crisis sample but positive for the post-crisis sample.

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Study on the Levels of Informal Statistical Inference of the Middle and High School Students (중·고등학생들의 비형식적 통계적 추리의 수준 연구)

  • Lee, Jung Yeon;Lee, Kyeong Hwa
    • School Mathematics
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    • v.19 no.3
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    • pp.533-551
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    • 2017
  • The statistical education researchers advise instructors to educate informal statistical inference and they are paying close attention to the progress of the statistical inference in general. This study was conducted by analyzing the levels and the traits of each levels of the informal statistical inference of the middle and high school students for comparing the samples of data and estimating the graph of a population. Research has shown that five levels of the informal statistical inference were identified for comparing the samples of data: responses that are distracted or misled by an irrelevant aspect, responses that focus on frequencies of individual data points and hold a local view of the sample data sets, responses that the student's view of the data is transitioning from local to global, responses that hold a global view but do not clearly integrate multiple aspects of the distribution, and responses that integrate multiple aspects of the distribution. Another five levels of the informal statistical inference were identified for estimating the graph of a population: responses that are distracted or misled by an irrelevant aspect, responses that focus only on representativeness, responses that consider both representativeness and variability and focus on one particular aspect of the distribution, responses that focus on multiple aspects of distribution but do not clearly integrate them, and responses that integrate multiple aspects of the distribution.

A Case Study on the Construction of the Sampling Frame and Sampling Design for 2008 Seoul Survey (2008 서울서베이 표본추출틀 구축 및 표본추출 사례 연구)

  • Kang, Hyun-Cheol;Park, Seung-Yeol;Kim, Jee-Youn;Kim, In-Soo;Lee, Dong-Su;Hwang, Ja-Eil;Park, Min-Gue
    • Survey Research
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    • v.10 no.3
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    • pp.157-172
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    • 2009
  • For a survey research in which the characteristics of the population of interest are investigated from a sample, representativeness of the sampling frame is one of the most important part to be considered. If the sampling frame fails to represent the population properly, statistical procedures based on the even efficient sampling design result in significant nonsampling biases and thus the statistical validities of the results could be damaged. But the construction of the reliable sampling frame that covers the population properly costs money and time and thus the sampling frame based on a census or a large scale survey is often used in practice. For example, the sampling frame based on the population households census is used for many household surveys in Korea. But due to the time difference between the census and a survey of interest, the sampling frame constructed from the census is expected to fail to cover the population of interest. Especially, one could expect a large amount of population and household movement in a large city like Seoul. Thus in our research, we considered the construction of new sampling frame and the procedure of sample selection for 2008 Seoul survey. We analyzed the sampling frame based on 2005 population households census and found that it does not represent the population properly. Thus, we proposed a new sampling frame based on resident registration DB for 2008 Seoul survey. We also proposed the sampling weights and estimator of the population mean based on the sample selected from the newly constructed sampling frame.

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International Comparison of Satisfaction Surveys for Employment Services (고용서비스 만족도 조사 국제 비교)

  • Kim, Ho W.;Kim, Taewoo
    • Journal of Service Research and Studies
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    • v.5 no.1
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    • pp.17-33
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    • 2015
  • This study looked for employment services satisfaction surveys done in the UK, USA and Korea. And through which derived the following suggestions for improving Korea the employment service satisfaction survey. First, in terms of research design improvements to ensure the representativeness of the sample region for each center and branch-specific (job seekers and recruiters) requires the sampling design based on user scale. In addition, the sample design should be applied when considering specific user can be distributed. US is restricted to participants within 60 days for sampling and sample extraction once a month at least. Next in terms of survey improvements, it is necessary to apply a weighting part considering the regional characteristics. For this, the correct analysis of the employment center by the internal and external environment is required. And in the case of non-face-to-face service, complaints about worknet use is likely to be channeled into complaints about job centers provide services. It needs to improve on this. And for the improvements of business processes service by an in-depth study, it can be seen to review the possible introduction of a British mystery shopper.

Uncertainty of Online TOC Analyzer in Water Quality Monitoring System (수질자동측정시스템에서 온라인 TOC 자동측정장치의 불확도 산출)

  • Lee, Chung-Yul;Lee, Yong-Woon;Lee, Jun-Hung;Lim, Boung-Jin;Kwon, Young-Jin;Khang, Bum-Ju;Hong, Young-Min
    • Korean Journal of Ecology and Environment
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    • v.40 no.2
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    • pp.193-200
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    • 2007
  • The objective of this study was to estimate uncertainty of online TOC analyzer in water quality monitoring system. A procedure for the estimation of measurement uncertainty of total organic compounds (TOC) based on the ISO approach is presented. It is based on a mathematical model that involves 4 input parameters (standardization, sensitivity, solute effect and representativeness). In this study, a major problem in estimating the uncertainty of online TOC analyzer was the solute effect. It was strongly depends on organic materials. So homogeneity of the sample is the most important consideration. Modified concentration and combined standard uncertainty was $4.71{\pm}0.36$ mg $L^{-1}$ by model modified in this study.

Comparison of somatotypes from various classification methods - Between 18 and 24 years old Korean Women - (체형분류 방법에 따른 체형 유형 간 비교 - 18~24세 여성을 대상으로 -)

  • Lee, Jeong-Yim;Nam, Yun-Ja
    • Fashion & Textile Research Journal
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    • v.6 no.2
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    • pp.221-228
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    • 2004
  • The purpose of this study was to compare somatotypes from various classification methods, to analyze the interrelation among each somatotype or each high frequency type, and to suggest the basis to interpret body size and shape more accurately. As a sample, the subjects were 97 Korean females between 18 and 24 years old. They were measured both anthropometric and photographic measuring in November, 1999. Their somatotypes were classified by three kinds of classification methods. The first method was based on the lateral view of body, the second involved Factor and Cluster analysis with the photographic measurements of anterior and lateral body, and the third involved Factor and Cluster analysis with the anthropometric measurements of whole body. The upper body was classified into three types, and the lower body was classified into 6 types from the lateral view of body. The bend-forward/q-2 was found to be the 'High-frequency type from the lateral view of body', and the Straight/n-1 was found to be the 'Straight type from the lateral view of body'. From the classification by the analysis of photographic measurements, the anterior body was classified into three types, the lateral was classified into 4 types. The X/${\varepsilon}$ type was found to be the 'High-frequency type from the analysis of photographic measurements of anterior and lateral body'. From the classification by the analysis of anthropometric measurements, the whole body was classified into three types. The i type was found to be the 'High-frequency type from the analysis of anthropometric measurements of whole body'. The significant interrelation was certified among some somatotypes or some High-frequency types. We found that both the view of body and the statistical analysis would make the clear definition of each somatotype possible. In order to certify the representativeness of High-frequency type, further analysis would be required of subjects who were in the High-frequency type and their body parts were in the High-frequency range.

A Total Survey Error Analysis of the Exit Polling for General Election 2008 in Korea (2008 총선 출구조사의 총조사오차 분석)

  • Kim, Young-Won;Kwak, Eun-Sun
    • Survey Research
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    • v.11 no.3
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    • pp.33-55
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    • 2010
  • In this study, we newly define the Total Survey Error(TSE) in exit poll and investigate the TSEs of the exit poll survey for the 18th general election of 2008 to analyse the cause of the exit poll prediction error. To explore the main cause and effect of the total survey error, the total survey error was divided by the sampling error which comes from sampling process of poll stations and the non-sampling error which comes from selecting voter and collecting responses from sampled voters in each electoral district. We consider the relationship between non-response rates and total survey error as well as non-sampling error. Also, we study the representativeness of the exit poll sample by comparing the sex/age distribution of the exit poll data and the National Election Commission poll data.

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Quantitative Comparison of Activity Calculation Methods for the Selection of Most Reliable Radionuclide Inventory Estimation

  • Hwang, Ki-Ha;Lee, Sang-Chul;Lee, Kun-Jai;Jeong, Chan-Woo;Ahn, Sang-Myeon;Kim, Tae-Wook;Kim, Kyoung-Doek;Herr, Y.H.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2003.11a
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    • pp.322-327
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    • 2003
  • It is important to know the accurate radionuclide inventory of radioactive waste for the reliable management. However, estimation of radionuclide concentrations in drummed radioactive waste is difficult and unreliable because of difficulties of direct detection, high cost, and radiation exposure of sampling personnel. In order to overcome these difficulties, scaling factors (SFs) have been used to assess the activities of radionuclides that could not be directly analyzed. A radionuclide assay system has been operated at KORI site since 1996 and consolidated scaling factor method has played a dominant role in determination of radionuclides concentrations. However, some problems are still remained such as uncertainty of estimated scaling factor values, inaccuracy of analyzed sample values, and disparity between the actual and ideal correlation pairs and the others. Therefore, it needs to improve the accuracy of scaling factor values. The scope of this paper is focused on the improvement of accuracy and representativeness of calculated scaling factor values based on statistical techniques. For the selection of reliable activity determination method, the accuracy of estimated SF values for each activity determination method is compared. From the comparison of each activity determination methods, it is recommended that SF determination method should be changed from the arithmetic mean to the geometrical mean for more reliable estimation of radionuclide activity. Arithmetic mean method and geometric mean method are compared based on the data set in KORI system.

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The Validity and Reliability of the Second Korean Working Conditions Survey

  • Kim, Young Sun;Rhee, Kyung Yong;Oh, Min Jung;Park, Jungsun
    • Safety and Health at Work
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    • v.4 no.2
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    • pp.111-116
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    • 2013
  • Background: The aim of this study was to evaluate the quality of the Second Korean Working Conditions Survey (KWCS), focusing on its validity and reliability. Methods: The external validity was evaluated by the assessment of sampling procedures and the response rate, in order to investigate the representativeness of the sample. The content validity was evaluated by the assessment of the development of the questionnaire, and the consistency of questions for the selected construct. The test-retest method was used to evaluate the reliability by means of a phone call survey of 30% of the respondents, who were randomly selected. The respondents' satisfaction regarding the survey procedures and interview time were analyzed to evaluate the quality of survey data. Results: The external validity was assured by an acceptable sampling procedure, rigid multi-stage stratified cluster random sampling. The content validity was also guaranteed by a reasonable procedure for the development of the questionnaire with a pretest. The internal consistency of the questions for work autonomy was maintained, with 0.738 of Cronbach's alpha. The response rate of 36% was lower than that of the European Working Conditions Survey (EWCS), with a contact rate of 66%, compared to 76% for the EWCS. The matching rates of the five retested questions were more than 98% reliable. Conclusion: The quality of the second KWCS was assured by the high external and content validity and reliability. The rigid sampling procedure and development of the questionnaire contributed to quality assurance. The high level of reliability may be guaranteed by the sophisticated field survey procedures and the development of a technical manual for interviewers. The technical strategies for a high response rate should be developed for future surveys.