Based on the results of pre-research in the form of observations, interviews, and documentation conducted in the fourth grade of SDN Karanganyar 01 Semarang, it was found that the learning resources used by teachers were still limited and not varied. Teachers have not integrated technology into learning activities that should be implemented to support the success of 21st century learning skills. This study aims to develop and test the viability of children's story websites as social studies learning media in the grade four of SDN Karanganyar 01 Semarang. This research is a Research and Development (R&D) study with the Borg and Gall development model. The instrument for data collection is in the form of a questionnaire validation sheet. Henceforth, the quantitative data was analyzed using criteria guidelines with assessment categories to determine the quality of the developed product. The validation results by the media expert validator get a percentage score of 87.5% in the very viable category, the validation results by the material expert validator get a percentage score of 95.3% in the very viable category and the validation results by the linguist get a percentage score of 95.3% in the very viable category. Based on the acquisition of the resulting data, it can be concluded that the children's story website as a social studies learning media for the grade four elementary school students is viable to use or valid. Keywords: children's story website, elementary school, learning media, social studies,

Based on the result of preresearch in the form of observation, interviews, and data on learning outcomes conducted in the fourth grade students at Nyi Ageng Serang Cluster Elementary school in Semarang, it was known that the social studies learning outcomes were not optimal because the learning model and media used were also not optimal. Although the teacher had used problem-based learning model, the students still had difficulties to identify problems and the media in the form of A4 print out pictures were not enough to help them. This study aimed to test the effectiveness of problem-based learning model assisted by blog media on the social studies learning outcomes in fourth grade students at Nyi Ageng Serang Cluster Elementary School in Semarang. This research used quantitative approach with the experimental type and nonequivalent control group design. The sample technique used cluster random sampling, with population of 172 students. The data collection used tests, observations and documentation. The hypothesis test result showed that the value of tcount = 4.007, and ttable = 2.009, because tcount ˃ ttable (4.007 ˃ 2.009) which means that the problem based learning model assisted by blog media was effective to increase the social studies learning outcomes of the fourth grade students. The n-gain test result of the experimental group was 0.40 categorized in medium criteria, whereas the n-gain test result of control group was 0.15, categorized in low criteria. The observation of students' activities using observation sheets showed the average score of the activity of experimental class students was 82%, which is better than the control class that only got 64%. The conclusion of this research is that the problem-based learning model assisted by blog media was effectively used in social studies learning in fourth grade students at Nyi Ageng Serang Cluster Elementary School in Semarang.