What are the distinctive characteristics of each character in Gibson's The Miracle Worker?

An inspiring drama of courage, persistence, and faith,
The Miracle Worker by William Gibson presents an interesting
interplay of characters.  Here is a discussion of the salient characteristics of the
main characters:

Captain Arthur
Keller

The patriarch of the Keller family,
Captain Keller is accustomed to having the final word on all household decisions.  He
has "stopped believing in wonders" regarding his child, Helen.  Although he indulges
Helen, after a while he decides that it may be better to put her into an institution. 
However, he does love his wife and agrees to write to The Perkins Institute in order to
learn if anything can be done for Helen.  When Anne Sullivan arrives, Captain Keller
regards her assertiveness as offensive and unbecoming of a woman; thus, he is in
constant conflict with her as he is skeptical of her
abilities.

Mrs. Keller [Kate
Keller]

The main characteristic of Mrs.
Keller is her overwhelming guilt over what has happened to her daughter.  As a result of
this guilt, she spoils her child, who acts like a feral animal.  As opposed to her
husband, Kate refuses to give up hope that something can be done; thus, she begs her
husband to not fire Anne when he becomes angry with her and to allow Anne to isolate
Helen from them in the garden house for a week. It is Kate Keller's enduring love for
her daughter and hope that she will be able to learn that supercedes all
else.

James
Keller

The son of Captain Keller, James is
rather unmotivated, often sarcastic, and especially jealous of all the attention given
to Helen.  However, he becomes the champion of Anne Sullivan, supporting her efforts to
teach Helen. In Act III, for example, he argues with his father to allow Anne to make
Helen fill the pitcher that she has flung at Anne. With this show of inner strength,
James wins some respect from his father.

Anne
Sullivan

A child of the slums who herself
has been blind, Anne has learned to endure.  She has the inner strength to insist that
Helen learn and behave properly. In addition to her fortitude, Anne believes in the
power of the soul, persisting in tapping this soul of Helen.  Driven by this belief and
her guilt over the death of her brother, Anne finally breaks through to Helen and
becomes "the miracle worker."  Her victory is both one for Helen and for herself as she
has conquered her inner demons and the forces of Captain Keller's disapproval of her as
well as having helped Helen.

Helen
Keller

Helen, of course, is the main
character of this play. Her handicaps notwithstanding, Helen is obviously a girl of high
intellect and cleverness as evinced in her locking Anne in her room and her other
devious acts.  Indeed, her brillance is the key to her breakthrough to the world of
learning since she was only six months when she learned to say "wa-wa," the key to her
awakening.  Her strong will, then, is turned to her great success as Anne Sullivan helps
her make the definitive transtition.