<![CDATA[The aims of study to determine the validity, practicality, and effectiveness of biology – based learning device based on the theory of social constructivism Vygotsky in Senior High School. This study included the type of research development. The development of learning device apply learning development procedure 4-D model which consists of define, design, develop, disseminate step. Results of analysis of research data suggests that the biology of learning devices based on the theory of social constructivism Vygotskyin Senior High School achieved the criteria of quailty, they are (1)validitywhere the validity of the lesson plan reach average3.77 (very valid category), the validityscore of the students book 3.75 (very valid category), and the validity average score of thestudents worksheet is 3.78 (very valid category). (2) the practicality, where rationally thetheory is stated that sitable to be used by experts and practitioners based on the score ofvalidity which very valid category and in real terms in the field has been applied with anoveral average of implementation 3.81 (very god implemented category). (3) effectiveness,in which the ability of teachers to manage learning with a value of 3.65 (very highcategory), the activity levels of students with an ideal time activity, the responses ofstudents with positive responses, and learning test results reachedwith the level of masteryclassically achieve 88.89% mastery]]>
