I collect various fashion dolls(Barbie, Disney, Begoths, Takara Jenny, Dollfie Plus) so this subject is of interst to me.
They tend to blur the line I guess...its funny I can consider the 12 inch Gi Joes to be dolls (& the 2 main 12 inch "do-it-yourself" doll companies, Volks & Obitsu, offer options to make both fashion dolls and more action oriented Gi Joe type dolls)
but the smaller action figures that are all hard plastic I find hard identifying as a doll, yet there are fashion dolls that are smaller than the usual 12 inch (like Bratz, Strawberry Shortcake.)
often it depends on how the company that makes the dolls want to market themselves as. Mattel, Integrity, Bleeding Edge make "fashion" dolls, Hot Toys, Dragon, Gi Joe make "action figures" but there's really no difference b/w the Uhura Barbie doll & the Joker Hot Toys 12 inch action figure.

They tend to blur the line I guess...its funny I can consider the 12 inch Gi Joes to be dolls (& the 2 main 12 inch "do-it-yourself" doll companies, Volks & Obitsu, offer options to make both fashion dolls and more action oriented Gi Joe type dolls)
but the smaller action figures that are all hard plastic I find hard identifying as a doll, yet there are fashion dolls that are smaller than the usual 12 inch (like Bratz, Strawberry Shortcake.)
often it depends on how the company that makes the dolls want to market themselves as. Mattel, Integrity, Bleeding Edge make "fashion" dolls, Hot Toys, Dragon, Gi Joe make "action figures" but there's really no difference b/w the Uhura Barbie doll & the Joker Hot Toys 12 inch action figure.