The report introduces the Home-Based Early Childhood Education Program developed by the KIRBS(Korean Institute for Research in the Behavioral Sciences) and presents the results of the study on effectiveness of the program carried out in 1988. A. Introduction of the Program The main objectives of the program were to educate the parents (mothers) through trained home-visitors regarding the knowledge, skills and attitudes toward child rearing and thereby help parents be able to facilitate development of their children. Specifically, the program was ⑴ to help parents recognize the importance of parents' role, ⑵ to help parents have self-efficacy about rearing children, and ⑶ ultimately to help parents help their children develop basic life skills and develop their potentiality in physical, cognitive, linguistic, and socio-emotional areas. The program package includes a parent education program and a child education program. The parent education program contains a wide variety of information about child rearing, stimulation, and education in order to help parents not only acquire the knowledge and skills but also enhance the sense of self-efficacy regarding child rearing. These knowledges and skills were organized into a set of 60 eight-page booklets, 12 each for the child ages 0-6 months, 7-12 months, 13-18 months, 19-24 months, and 25-36 months, respectively. The child porgram includes such area as self-help, number, language and communication, social behavior, safety, and other activities appropriate for their ages. The program was delivered to the mothers and children through the trained home visitors who were the female college graduates majored in early childhood education and were trained by the research team before they were assigned to 5-6 families each in the urban slums. The home-visitors made a total of 24 visits in 1988, evenly distributed year round. Upon visiting, they handed out to mothers the appropriate booklets, explained about the contents, and demonstrated as necessary how to use the know ledges and skills in the booklets. Each home-visitor recorded daily activities in the diary provided to her. B. Effectiveness of the Program METHOD Subjects The families having children aged 0 to 30 months were selected in Seoul city, Seongnam city, and Kwangju city. When the program startd, there were 162 pairs of mothers and children who were divided into five age brackets. At the end of the project, there remained 138 pairs. The drop-out rate was 14.8%. The average ages of the mothers and fathers were 28 years and 32 years old, respectively. Measures In order to evaluate the effectiveness of the program, mothers were given pre-tests in the begining of the home-visiting proper and during the last part of home visiting were they given the post-test. In order to test the size of change, Parent Attitudes Questionaire, Home Observation for Mea-surement of Environment, Teaching Observation Technique of Mother, and Social Maturity Test were administered. RESULTS 1. Change in Parent Attitudes : The pre-and post-test comparison of the scores revealed significant attitudinal changes across the three dimensions of attitiudes toward child education(t＝4.50, p＜.01), attitude toward children (t＝2.23, p＜.05), and belief about being parent(t＝2.16, p＜.05). 2. Change in Family Enviromnent : Data obtained through observation of mother and interview regarding family environment showed statistically significant change between pre-test and post-test across all 6 dimensions. Changes in physical environment, provision of play materials, variety in daily stimulation, and mother's emotional and verbal responsivity are statistically significant at p＜.01 level. 3. Change in Mother's Verbal Instruction : Mother's verbal behavior was observed while she was interacting with her child in play activities and in making playthings. Observations in three 20-minutes sessions at the begining and end of the intervention yielded average frequencies over 2 dimensions(or 12 sub-dimensions). Amount of explanation increased and so did the frequency in 4 of 7 sub-dimensions pertaining to democratic verbalizations. All of sub-dimensions of the mothers' authoritative verbalizations decreased significantly. 4. Effects of Mother's Change on Children : It was expected that positive changes in mother by means of demonstration and explanation by means of brochure and home-visiting will have positive impact on children. Since the children in our group were too young to receive psychological test appropriately for tapping their developmental levels, we resorted to an indirect method of measuring changes in children. The home visitors administered through interview the social maturity scale to the mothers who responded to each item. The amount of social maturity age increase tended to be higher among the younger children than among the older. The children in the age bracket of 7-12 months showed the highest increase. 5. Response of Parents and Home Visitors : Quantitative analyses thus show positive changes in mothers and children. These quantitative results aside, from the diffusion vantage point more important of the program would be how the parents felt about the porgram. A narrative report indicated that the program was received positively by the parents. This was shown by the opinion survey after the intervention. Subsequent to the intervention, the home visitors and the parents were inquired about how they felt about the porgram. The majority of parents(98.9％) felt that the program was helpful for the education of children, brothers and sisters changed positively, and neighbors wanted to participate in the program. All home visitors were satisfied with the participation in this program as home visitors and responded that the program was helpful for education of children.