Theorists By willt Period: Jan 10, 1782 to Jan 10, 1852 Froebel Period: Jan 10, 1870 to Jan 10, 1952 Montessori Period: Jan 10, 1885 to Jan 10, 1948 Issacs Period: Jan 10, 1896 to Jan 10, 1980 Piaget Period: Jan 10, 1896 to Jan 10, 1934 Vygotsky Period: Jan 10, 1896 to Jan 10, 1974 Winnicott Period: Jan 10, 1902 to Jan 10, 1979 Erikson Period: Jan 1, 1915 to Jan 10, 2010 Bruner