• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.3
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• pp.214-219
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• 1991

To clarify the relationship between ambient water temperature and heading characteristics of rice (Oryza sativa L.), twelve of varieties rice were grown in a cold tolerance screening field where water temperature was controlled by continuous cold water irrigation system to test the cold tolerance of rice. When cold water was continuously irrigated with 5 cm of water depth, the water had stagnated for about three hours, and the water temperature increased gradually from inlet toward outlet in the experimental plot. The fluctuation of water temperature was well synchronized with that of ambient air temperature, and the water temperature near outlet became higher than the air temperature at the vegetative phase, while became lower at the reproductive phase of rice plant community. The leaf development rates on main culm increased by increased water temperature. The rice varities, Fukuhikari, Sangpungbyeo and YR3486-16-2 were more sensitive than the others in the response of leaf development to water temperature. However, Janack and Milyang 42 were comparatively less sensitive to water temperature in leaf development. Janack and Paro -white rices required longer days to develop one leaf on main culm at reproductive phase than at vegetative phase. Varietal difference in days required to develop one leaf on main culm of rice plant was more distinctive at the reproductive phase when water temperature was relatively lower than at the vegetative phase with relatively higher water temperature condition. No difference was found between the growth phases, vegetative and reproductive, in the response of average leaf developmental rates to water temperature under the similar air temperature condition. The estimated average days required to develop one leaf on main culm decreased by 1.3 day by 1$^{\circ}C$ increase in water temperature. Varietal differences in the total number of leaves on main culm depended upon the water temperature, in which the varieties such as Fukuhikari, Gwangmyeon-gbyeo, China 988, and YR3486-16-2 showed increased one leaf by increased water temperature, while Sobaekbyeo, Paro-white, Sangpungbyeo, Pungsanbyeo, Samgangbyeo, and Milyang 42 were kept at the same leaf number regardless of water temperature. However, the total leaf number on main culm and days to heading of Janack increased by increased water temperature. The other varieties showed the shortened days to heading by the increase in water temperature with noticeable varietal differences regardless of the variation in the total number of leaves on main culm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1000-1007
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• 2005

The aim of the present study was to examine the relationship of maternal factors such as knowledge, attitude and practice of weaning with infant feeding. The subjects were 103 mothers visiting a public health center in Gumi, Kyungbook who filled out self-administered Questionnaires. First of all, about $90\%$ of the participants recognized the importance of complementary foods and proper weaning practices. The response for the recognition of the importance of infant weaning process showed a significant difference by education levels. Concerning an appropriate time for the introduction of weaning foods, $53\%$ of mothers had commenced weaning at age $4\~6$ months, while $38\%$ had done so at age $6\~8$ months. Approximately $76\%$ of mothers fed their babies without the knowledge of age-related weaning method and type of weaning foods. There were no statistical differences in maternal weaning knowledges between levels of education and house income. Mothers with higher levels of education and family income tended to show high perception scores regarding possibility of food allergies caused by baby foods. A demand for reliable sources and education related to nutritious weaning foods and weaning practices were strong in the group with higher education. Knowledge of weaning method and baby foods were obtained by 59 of the 103 mothers from mass media, 35 from friends caring babies, and 9 obtained advice from health professionals or family. Advice from the heath professionals was not the main influence on their decision to introduce weaning foods. Although commercial baby foods are the most commonly used as first weaning foods, those with higher education groups considered commercial baby food are not nutritionally better than home-maid foods. The current findings suggest to us that to improve weaning process, mothers should be educated on the selection and preparation of nutritious, balanced weaning foods and on good weaning practices. It is advised that supportive health professionals from community public health centers should lead the education of infant feeding practices based on maternal characteristics and on basic food and nutritional knowledge.

• Asia pacific journal of information systems
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• v.24 no.4
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• pp.559-575
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• 2014

Individual investors are increasingly flocking to message boards to seek, clarify, and exchange information. Businesses like Seekingalpha.com and business magazines like Fortune are evaluating, synthesizing, and reporting the comments made on message boards or blogs. In March of 2012, Yahoo! Finance Message Boards recorded 45 million unique visitors per month followed by AOL Money and Finance (19.8 million), and Google Finance (1.6 million) [McIntyre, 2012]. Previous studies in the finance literature suggest that online communities often provide more accurate information than analyst forecasts [Bagnoli et al., 1999; Clarkson et al., 2006]. Some studies empirically show that the volume of posts in online communities have a positive relationship with market activities (e.g., trading volumes) [Antweiler and Frank, 2004; Bagnoli et al., 1999; Das and Chen, 2007; Tumarkin and Whitelaw, 2001]. The findings indicate that information in online communities does impact investors' investment decisions and trading behaviors. However, research explicating the correlation between information on online communities and stock market activities (e.g., trading volume) is still evolving. Thus, it is important to ask whether a volume of posts on online communities influences trading volumes and whether trading volumes also influence these communities. Online stock message boards offer two different types of information, which can be explained using an economic and a psychological perspective. From a purely economic perspective, one would expect that stock message boards would have a beneficial effect, since they provide timely information at a much lower cost [Bagnoli et al., 1999; Clarkson et al., 2006; Birchler and Butler, 2007]. This indicates that information in stock message boards may provide valuable information investors can use to predict stock market activities and thus may use to make better investment decisions. On the other hand, psychological studies have shown that stock message boards may not necessarily make investors more informed. The related literature argues that confirmation bias causes investors to seek other investors with the same opinions on these stock message boards [Chen and Gu, 2009; Park et al., 2013]. For example, investors may want to share their painful investment experiences with others on stock message boards and are relieved to find they are not alone. In this case, the information on these stock message boards mainly reflects past experience or past information and not valuable and predictable information for market activities. This study thus investigates the two roles of stock message boards-providing valuable information to make future investment decisions or sharing past experiences that reflect mainly investors' painful or boastful stories. If stock message boards do provide valuable information for stock investment decisions, then investors will use this information and thereby influence stock market activities (e.g., trading volume). On the contrary, if investors made investment decisions and visit stock message boards later, they will mainly share their past experiences with others. In this case, past activities in the stock market will influence the stock message boards. These arguments indicate that there is a correlation between information posted on stock message boards and stock market activities. The previous literature has examined the impact of stock sentiments or the number of posts on stock market activities (e.g., trading volume, volatility, stock prices). However, the studies related to stock sentiments found it difficult to obtain significant results. It is not easy to identify useful information among the millions of posts, many of which can be just noise. As a result, the overall sentiments of stock message boards often carry little information for future stock movements [Das and Chen, 2001; Antweiler and Frank, 2004]. This study notes that as a dependent variable, trading volume is more reliable for capturing the effect of stock message board activities. The finance literature argues that trading volume is an indicator of stock price movements [Das et al., 2005; Das and Chen, 2007]. In this regard, this study investigates the correlation between a number of posts (information on stock message boards) and trading volume (stock market activity). We collected about 100,000 messages of 40 companies at KOSPI (Korea Composite Stock Price Index) from Paxnet, the most popular Korean online stock message board. The messages we collected were divided into in-trading and after-trading hours to examine the correlation between the numbers of posts and trading volumes in detail. Also we collected the volume of the stock of the 40 companies. The vector regression analysis and the granger causality test, 3SLS analysis were performed on our panel data sets. We found that the number of posts on online stock message boards is positively related to prior stock trade volume. Also, we found that the impact of the number of posts on stock trading volumes is not statistically significant. Also, we empirically showed the correlation between stock trading volumes and the number of posts on stock message boards. The results of this study contribute to the IS and finance literature in that we identified online stock message board's two roles. Also, this study suggests that stock trading managers should carefully monitor information on stock message boards to understand stock market activities in advance.

• Korea journal of population studies
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• v.11 no.1
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• pp.58-75
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• 1988

1.Objectives of the Study It is a well known fact that a prompt and reliable data on demographic information is essential in a proper planning and evaluation of any program of national or community level. Especially vital statistics are an important demographic component among demographic information. Realizing the importance of vital statistics, the government has made some efforts for years to improve the vital registration system which has a close relationship with the production of vital statistics. However, it is still observed that there are some limitations in utilizing vital registration data due to considerable amount of vital events which are never registered and registered but not in time or inaccurately, even though vital registration system in Korea has sound legal basis. In this connection, the objectives of the study is as follows :(1) To examine some problems of the vital registration system in various aspects, (2) To make improvement programme of continuous Demographic Survey as a supplementary source of vital statistics, and (3) To find out some alternatives for making it possible to produce and utilize the reliable vital statistics by developing analytical methodologies on that. 2. Current Situation of Vital Registration System All the vital events, i.e. births, deaths, marriages and divorces, are to be registered in time under the Civil Registration Law, Statistics Law and Regulation on Vital Statstics as a duty of people. Some recent tendencies in each of recent registration are summarized as below: (1) The completeness of vital registration .Out of all births which are occurred during a year, around 75% of those compared to the estimates are registered in the year of occurrence. .In case of death registration, the percentage of registration in the year of occurrene has been gradually increased from 86.2% in the year of 1980, but it is still below the level of 90% compared to the estimates. .The percentage of registration for marriages and divorces in the year of occurrence out of total registered numbers was revealed to be 69% and 73% respectively in 1985. (2) Continuous Demographic Survey .It is a kind of sample survey for the purpose of producing reliable vital statistics which could not be provided by the vital registration. .It covers about 17, 000 sample households at national level and important information for vital events are collected in every month by 323 expertized enumerators who are regular staff of the government. .Although the result of the survey seems to be more reliable than of vital registration, the reliability of the data is still bellow the acceptable level if compared with relevant information from other sources such as population census or special surveys. 3. Problems of Vital Registration System There are four major obstacles in improving vital registration system in Korea; (1) In general, policy priority is not given on any programme of improving vital registration system. It is, therefore, very difficult to formulate comprehensive programme through having cooperation from related authorities and sufficient financial assistance. (2) In all the laws related and system itself, there is substantial degree of overlap and irrationality. Registration of each vital event is maintained according to several laws and regulation such as Civil Registration Law, Statistics Law, Resident Registration Law and Regulation on Vital Statistics. However they are mutually overlapped and overall supervision can not be done systematically due to lack of co-operation among the authorities concerned. (3) The administration of vital registration system seems to be working inefficiently, because of most of civil servants who are in charge of vital registration are lacking of conception on vital statistics and also there is a certain extent of regidity in handling the works. Therefore, they are doing their jobs in a passive way. (4) A substantial proportion of vital events occurred is not registered within the legal time limit (i.e. within one month after the occurrence in case of birth and death) or not registered forever. Some of social customs and superstitution seem to be the potential causes especially in case of births and deaths. 4. Recommendations for the Improvement of Vital Statistics (1) Reporting systems such as civil registration, vital statistics and resident registration should be integrated under the single law. Also, administrative supervision, personnel and budget with regard to the registration system should be under the control of a single ministry. (2) It is necessary to simplify the procedures and methods of reporting vital events, i.e., reducing number of sheets of the form, making corrections easily, reducing registration items, etc. (3) Continuous Demographic Survey as a supplementary source of vital registration should be improved and special ad-hoc surveys should be conducted wth regular interval. (4) In-depth analysis should be done using various sources of data on vital statistics. 5. Concluding Remarks From this study, we can notice that temporary campaign and motivation programs are not sufficient to improve the quality of vital statistics. Strong intentions and continuous efforts of the government are needed for the improvement of the vital registration system. Furthermore, most of the data collected through the registration are not properly analyzed and utilized, partly due to the lack of appreciation among high-level governmental officials of the need for vital statistics. It is, therefore, requested that long-term improvement programs of vital statistics be implemented with policy priority and continuous efforts be given to this purpose as a long-term goal of development in Korea.

• Korean Journal of Heritage: History & Science
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• v.49 no.1
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• pp.44-67
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• 2016

This article studied the character of Bogamri group and trends in the surrounding area through recently excavated stone chambers. The first type of stone chamber constructed at Bogamni cemetry was Northen Kyushu style stone chamber tomb with corridor. However, According to recent survey Wa style vertical stone lined tomb had constructed earlier than these stone chamber along the southwest cost. It is likely that the background of these Wa style stone tomb was the beginning of formal diplomatic relations between Baekje and Wa. At first, grave goods as well as burial had been Wa style, but gradually local burial element and mortuary practices added. And large tomb had beginning to appear. The representative tombs are Yeongam Okyari Jangdong tomb and Naju Gaheugni Shinhueng tomb. They were built in the middle of the fifth century. It is most likely that the location was selected with regard to the use or securing of inland waterway. But the next step, Yeongsangang river style stone chamber with corridor had constructed at Jeongchon tomb. That tomb is very close to Bogamni tombs and structure and grave goods are very similar also. So these two groups were considered to be the same community. Hereby, It is believed that the inland waterway using power had been turned over to Bogamni group. Bogamni group had constantly constructed stone chamber until seventh century. This represent that Bogamni group had thrived as a leading force in the Yeongsangang river basin. After under the direct control of Baekje, Bogamni group had continued the close relationship with Wa. For this reason, Bogamni group had influenced southwest cost as well as Yeongsangang river basin. It can be estimated by the Bogamni style stone chamber founded at islands of Shinan.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.740-753
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• 2022

This study was conducted to develop and apply an out-of-school STEAM program model based on Social-Emotional Learning (SEL) for underprivileged students in the lower grades. To this end, a STEAM program based on SEL was developed, with the following characteristics. First, by integrating traditional STEAM learning elements and SEL elements, a structured program was designed with consistent stages, including mindfulness meditation→present an authentic situation→creative design→emotional experiences→reflection. Second, the program was structured so that elementary school students could develop mathematical thinking and scientific inquiry skills in problem-solving situations in daily life. Third, the detailed themes for each STEAM program involved storytelling-based problem situations, as well as activities centered on play and sympathy to reflect the educational needs of underprivileged students. From these characteristics, a total of five programs were developed and applied to 16 teachers and 354 lower-grade elementary school students in 16 community children centers nationwide. The results were as follows. First, while students' satisfaction with the STEAM program was 4.16, there were no significant differences in STEAM satisfaction according to gender. Second, while all students' interest and self-efficacy, which was one of sub factors of STEAM attitude, were significantly improved, no significant difference was seen in STEAM attitudes according to gender. Third, although students' SEL competencies were not significantly improved, relationship skills, which were among the sub factors of SEL competencies, were significantly improved, and there were no significant differences in SEL competencies according to gender. From these results, a discussion on the effect of the out-of-school STEAM program for underprivileged students and directions for follow-up studies was suggested.

• Asia pacific journal of information systems
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• v.18 no.3
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• pp.91-121
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• 2008

Electronic commerce, commonly known as e-commerce or eCommerce, has become a major business trend in these days. The amount of trade conducted electronically has grown extraordinarily by developing the Internet technology. Most electronic commerce has being conducted between businesses to customers; therefore, the researches with respect to e-commerce are to find customer's needs, behaviors through statistical methods. However, the statistical researches, mostly based on a questionnaire, are the static researches, They can tell us the dynamic relationships between initial purchasing and repurchasing. Therefore, this study proposes dynamic research model for analyzing the cause of initial purchasing and repurchasing. This paper is based on the System-Dynamic theory, using the powerful simulation model with some restriction, The restrictions are based on the theory TAM(Technology Acceptance Model), PAM, and TPB(Theory of Planned Behavior). This article investigates not only the customer's purchasing and repurchasing behavior by passing of time but also the interactive effects to one another. This research model has six scenarios and three steps for analyzing customer behaviors. The first step is the research of purchasing situations. The second step is the research of repurchasing situations. Finally, the third step is to study the relationship between initial purchasing and repurchasing. The purpose of six scenarios is to find the customer's purchasing patterns according to the environmental changes. We set six variables in these scenarios by (1) changing the number of products; (2) changing the number of contents in on-line shopping malls; (3) having multimedia files or not in the shopping mall web sites; (4) grading on-line communities; (5) changing the qualities of products; (6) changing the customer's degree of confidence on products. First three variables are applied to study customer's purchasing behavior, and the other variables are applied to repurchasing behavior study. Through the simulation study, this paper presents some inter-relational result about customer purchasing behaviors, For example, Active community actions are not the increasing factor of purchasing but the increasing factor of word of mouth effect, Additionally. The higher products' quality, the more word of mouth effects increase. The number of products and contents on the web sites have same influence on people's buying behaviors. All simulation methods in this paper is not only display the result of each scenario but also find how to affect each other. Hence, electronic commerce firm can make more realistic marketing strategy about consumer behavior through this dynamic simulation research. Moreover, dynamic analysis method can predict the results which help the decision of marketing strategy by using the time-line graph. Consequently, this dynamic simulation analysis could be a useful research model to make firm's competitive advantage. However, this simulation model needs more further study. With respect to reality, this simulation model has some limitations. There are some missing factors which affect customer's buying behaviors in this model. The first missing factor is the customer's degree of recognition of brands. The second factor is the degree of customer satisfaction. The third factor is the power of word of mouth in the specific region. Generally, word of mouth affects significantly on a region's culture, even people's buying behaviors. The last missing factor is the user interface environment in the internet or other on-line shopping tools. In order to get more realistic result, these factors might be essential matters to make better research in the future studies.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.12 no.1
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• pp.138-148
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• 2001

The focus of the research was on identifying the risk factors that may result in unprepared intercourse among the adolescent from an ecological systems prospective. A survey questionnaire was conducted from September through December 1999 to 2326 youths, ages from 13-18 years old. After eliminating thirty respondents from Unwed Mother's Home we found that 8.8% of the remaining respondents had experienced sexual intercourse. Of those, 5% of the female and 13.4% of male adolescents has had sexual intercourse, showing 2.7 times more for the male sample population. Broken down to age groups, 3.2% of the thirteen years old group and 19.2% of the eighteen years old group had experienced intercourse, an almost six fold increase in the older age group. To find out the differences between those who had and not had experienced intercourse the group was then divided into two comparative groups by same sex and age variables. Findings from comparative analysis identified five ecological system risk factors among the youth sample that had intercourse；First, individual factor：adolescents who thought less of themselves or didn't consider their potentials, those more exposed other risk behaviors such as drinking, smoking, drugs, runaway and come in contact with pornography, those who thought they knew more about sex and etc. Second, family factor：those who thought family was less important, had less supportive family, higher or lower income family and etc. Third, peer factor：Both groups thought friends were important and had their support. The group with intercourse experience seems to be think that more peers are experiencing other risk behavior. Fourth, school factor：Those in the group who had experienced intercourse seems to think school is less important and with lower academic achievements. Fifth, community factor：There were no statistical significant differences found between the two groups. The overall results from this study implies that if we want to prevent our youths from having unprepared intercourse during adolescence the significance of having meaningful emerging self, family relationship and school experience is important. This study identified the risk factors leading to adolescent sexual intercourse but further research is necessary in finding out about their predictability.

• Asia pacific journal of information systems
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• v.19 no.2
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• pp.43-72
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• 2009

Recently, user-created content (UCC) have emerged as popular medium of on-line participation among users. The Internet environment has been constantly evolving, attracting active participation and information sharing among common users. This tendency is a significant deviation from the earlier Internet use as an one-way information channel through which users passively received information or contents from contents providers. Thanks to UCCs online users can now more freely generate and exchange contents; therefore, identifying the critical factors that affect content-generating activities has increasingly become an important issue. This paper proposes a set of critical factors for stimulating contents generation and sharing activities by Internet users. These factors were derived from the theories of folklores such as tales and songs. Based on some shared traits of folklores and UCC content, we found four critical elements which should be heeded in constructing UCC contents, which are: context of culture, context of situation, skill of generator, and response of audience. In addition, we selected three major UCC websites: a specialized contents portal, a general internet portal, and an official contents service site, They have different use environments, user interfaces, and service policies, To identify critical factors for generating, sharing and transferring UCC, we traced user activities, interactions and flows of content in the three UCC websites. Moreover, we conducted extensive interviews with users and operators as well as policy makers in each site. Based on qualitative and quantitative analyses of the data, this research identifies nine critical factors that facilitate contents generation and sharing activities among users. In the context of culture, we suggest voluntary community norms, proactive use of copyrights, strong user relationships, and a fair monetary reward system as critical elements in facilitating the process of contents generation and sharing activities. Norms which were established by users themselves regulate user behavior and influence content format. Strong relationships of users stimulate content generation activities by enhancing collaborative content generation. Particularly, users generate contents through collaboration with others, based on their enhanced relationship and specialized skills. They send and receive contents by leaving messages on website or blogs, using instant messenger or SMS. It is an interesting and important phenomenon, because the quality of contents can be constantly improved and revised, depending on the specialized abilities of those engaged in a particular content. In this process, the reward system is an essential driving factor. Yet, monetary reward should be considered only after some fair criterion is established. In terms of the context of the situation, the quality of contents uploading system was proposed to have strong influence on the content generating activities. Among other influential factors on contents generation activities are generators' specialized skills and involvement of the users were proposed. In addition, the audience response, especially effective development of shared interests as well as feedback, was suggested to have significant influence on contents generation activities. Content generators usually reflect the shared interest of others. Shared interest is a distinct characteristic of UCC and observed in all the three websites, in which common interest is formed by the "threads" embedded with content. Through such threads of information and contents users discuss and share ideas while continuously extending and updating shared contents in the process. Evidently, UCC is a new paradigm representing the next generation of the Internet. In order to fully utilize this innovative paradigm, we need to understand how users take advantage of this medium in generating contents, and what affects their content generation activities. Based on these findings, UCC service providers should design their websites as common playground where users freely interact and share their common interests. As such this paper makes an important first step to gaining better understand about this new communication paradigm created by UCC.

• Korea journal of population studies
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• v.4 no.1
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• pp.105-130
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• 1981

This study was conducted to compare the characteristics of high performane areas for family planning with that of low performance areas and to find factors which strongly affected contraceptive practice behavior. For the study, eight areas were selected from 274 rural family planning canvassing areas of Korean Population Policy and Program Evaluation Study, which was an action study operated in all areas of Cheju Island from July 1, 1976 until December 31,1979. As a first step of the action study, Cheju Island was devided up 318 family planning canvasser areas Each area was consisted of 200 households in rural district and 300 households in urhan one Duriog the period of project, each canvassing area had been managed by a female family planning canvasser, selected by director of health center considering several individual conditions needed for family planning activities Basic activities of canvassers were to counsell all the eligihie couples in own charged area about family planning methods and also to distribute contraceptives such as condoms and oral pills. In case couples desire to accept sterilization including vasectomy and tubal-ligation, the canvassers played a linking role connecting potential client with family planning field workers. Canvassng areas shows significant differentce in performance for family planning, nevertheless they are supposed to have almost the same conditions regarding family planning distribution channel. Because the purpose of the Cheju project was to eliminate all the problems that existed in governmental distribution system, that is to remove geographic, economic, cognitive and administrative barriers Accumulated performances of family planning methods accepted by residents in each area were calculated by eligible women aged 14-49. And then canvassing areas were ranked according to performance score. Consequently, 4 areas in extremely high and low family planning performance areas were selected respectively. Major results were obtained by comparing characteristics of high performance area with that of low performance areas, which are as follows: 1. The mean number of living children was about the same both in high and low performance areas for family planning. But respondents' mean age (38.5) in high performance areas was higher than that (37.0) in low performance areas 2. Respondents' perception in the expectant educational level of others' children in high performance areas was higher than that in low performance areas, although respondents educational level, monthly expenditure and ratio of children in high school and above was not different. 3. Ratio of ownerships of TV and newspaper in high performance areas was highen than that in low performance areas 4. The duration of canvasser' charge in high performance areas was longer than that of low performance areas, showing the fact that canvassers didn't move cut in high performance areas 5. In high performance areas, canvassers' houses were relatively located in the center part of the village. And so villagers resided in near distances from the anvasser's house 6. 4H clubs' activities in high performance areas were more active than those in low performance areas Therefore it was assumed that cohesiveness of community in high performance areas were stronger than that in low areas. 7. Canvassers' family planning practice rate was higher than that in low performance areas, and also canvassers' human relationship was more sociable than that of canvassers in low performance areas. 8. Fourteen variables which showed relatively high significance level in $X^2$ and F test were selected as independent variables for stepwise regression analysis. According to the results of regression analysis. five of 14 variables-distributors education level ($R^2$=.4439), duration of distributor's charge ($R^2$=.6166), 4H club activities ($R^2$=.6697), canvasser's contraceptive practice ($R^2$=.7377) and location of distributions house ($R^2$=.8010) explained 80.1 percent of total variance.