TITLE: 
                        
                            An Additional Consideration of Reliability and Validity of the Differentiation of Self Scale in Two Domains
                                
                                
                                    AUTHORS: 
                                            Koji Kudo 
                                                    
                                                        KEYWORDS: 
                        Differentiation of Self, Domain Specific Validation, Interpersonal Domain, Intrapsychic Domain, Test-Retest Reliability 
                                                    
                                                    
                                                        JOURNAL NAME: 
                        Psychology,  
                        Vol.9 No.10, 
                        September
                                                        17,
                        2018
                                                    
                                                    
                                                        ABSTRACT: This study addressed the insufficient verification of reliability and validity of the Differentiation of Self Scale in Two Domains (DSS-2D). Although the DSS-2D is the first measure in Japan that satisfies the three requirements (corresponding to two domains, applicable to a wide range of adolescents, and a moderate number of items), verification of reliability and validity of the DSS-2D has remained insufficient. Two questionnaire surveys were conducted with university students (n = 70 at T1, n = 68 at T2). The interval of the surveys was one month. The results indicate that the DSS-2D had sufficient test-retest reliability and concurrent validity in each domain of differentiation of self. These results provide support for the DSS-2D as a valid and adequate measure for use in Japan.