strong typingobject is of exactly one typea string is always stringan integer always an integer counterexamplesphpjavascriptcchar can be interpreted as shortvoid can be everything dynamic typingno variable declaration variable names can be assigned to different data types in the course of program an object' attributes are checked only at run time duck typing (an object is defined by its methods and attributeswhen see bird that walks like duck and swims like duck and quacks like ducki call that bird duck james whitcomb riley member of the helmholtz association slide