Here is a "live chat" with Koko -- with Dr. Patterson, Koko's trainer/keeper as translateor.

Below is an analysis of Koko's signed words as given here, using the CLAN program from CHILDES.

This reveals a MLU (Mean Length of Utterance) of 1.9 -- about that expected from a 22 month old child.
For humans, MLU correlates nearly r=1 for the first 4 years.  And what is Koko's interest in nipples about?
                                      
   [INLINE] HaloMyBaby is the moderator of the chat on AOL, DrPPatrsn is
   Koko's friend and trainer, and LiveKOKO is Koko the gorilla.
   Begin Transcript:
   HaloMyBaby: Welcome, Dr. Patterson and Koko, we're so happy you're
   here!
   DrPPatrsn: You're welcome!
   HaloMyBaby: Is Koko aware that she's chatting with thousands of people
   now?
   LiveKOKO: Good here.
   DrPPatrsn: Koko is aware.
   HaloMyBaby: I'll start taking questions from the audience now, our
   first question is: MInyKitty asks Koko are you going to have a baby in
   the future?
   LiveKOKO: Pink
   DrPPatrsn: We've had earlier discussion about colors today
   LiveKOKO: Listen, Koko loves eat
   HaloMyBaby: Me too!
   DrPPatrsn: What about a baby? She's thinking...
   LiveKOKO: Unattention
   DrPPatrsn: She covered her face with her hands....which means it's not
   happening, basically, or it hasn't happened yet.
   LiveKOKO: I don't see it.
   HaloMyBaby: That's sad!
   DrPPatrsn: In other words, she hasn't had one yet, and she doesn't see
   it happening. She needs several females and one male to have a family.
   In our setting it really isn't possible for her to have a baby.
   HaloMyBaby: Do you see that situation changing when you get the
   Gorilla preserve on Maui?
   DrPPatrsn: Yes, we do.
   LiveKOKO: Listen.
   DrPPatrsn: Koko wants to hear on the phone as we're doing this.
   HaloMyBaby: Hi Koko! I can hear her! She breathed at me! This is so
   cool! In case you're curious, here's how Koko is able to participate
   in this chat: Dr. Penny Patterson is signing the questions to Koko
   from the online audience and a typist is entering for her.
   DrPPatrsn: I'm working to create a family. In Hawaii, we'll have the
   ability to do that she's almost assured to have a family of her own.
   HaloMyBaby: So she really is looking forward to this!
   DrPPatrsn: She's making happy sounds now...
   Question: EFRN asks: Would Koko like to have a kitten, a dog, or
   another Gorilla as a friend?
   LiveKOKO: dog
   DrPPatrsn: She actually has two dog friends right now one kitty and
   two gorillas.
   HaloMyBaby: SBM87: ask What are the names of your kittens? (and dogs?)
   LiveKOKO: foot
   DrPPatrsn: Foot isn't the name of your kitty
   HaloMyBaby: Koko, what's the name of your cat?
   LiveKOKO: no
   DrPPatrsn: She just gave some vocalizations there... some soft puffing
   HaloMyBaby: I heard that soft puffing!
   DrPPatrsn: Now shaking her head no.
   Question: Do you like to chat with other people?
   HaloMyBaby: That was from Rulucky!
   LiveKOKO: fine nipple
   DrPPatrsn: Nipple rhymes with people, she doesn't sign people per se,
   she was trying to do a "sounds like..."
   HaloMyBaby: BSikor439 wants to know, Koko, Which of your paintings do
   you like most? Is she still painting?
   DrPPatrsn: She hasn't seen her paintings for awhile. She is still
   painting.
   HaloMyBaby: Tell us what she's doing right now!
   DrPPatrsn: She's re-arranging the furniture in her room, basically.
   Let me move some of these boxes back. There's a lot of stuff her.e Let
   me ask her if she LIKES to paint...one second.
   HaloMyBaby: Dr. Patterson, why is this such an important project?
   DrPPatrsn: We're learning so many things on many levels, many of which
   I did not predict.
   HaloMyBaby: You've devoted your whole life to it! What are we
   learning?
   DrPPatrsn: I had started to simply see if another species could
   communicate with us in another language, such as sign language. She is
   very creative with that language and can talk about abstract things.
   HaloMyBaby: I can see that!
   DrPPatrsn: Surprising that she can be so creative. What I've
   discovered is that she has already got the system, it's not that I
   gave her this system. I simply share the vocabulary with her. It gives
   us a window into another species. They are our closest living
   relatives. It tells us so much about how we've evolved...learning so
   much about things such as reproductive physiology how they would like
   to see things happen in the future....she will respond to things at a
   sophisticated level...she actually discriminates phoning.
   Question: I've heard people say she's not really communicating -- I
   think she's smarter than we are-- after all, how many of us can speak
   Gorilla!
   DrPPatrsn: Exactly! She has learned our language but we haven't
   learned hers.
   HaloMyBaby: What new is there to learn after 26 years?
   DrPPatrsn: It says a lot about her species. Well, every day brings new
   surprises in terms of learning about gorillas in order to save them,
   but also about learning about ourselves. The things she comes up with
   surprise me.
   HaloMyBaby: A basic earthy question for Koko from Earth2Kim: Koko,
   what is your favorite food, fruit, or vegetable?
   DrPPatrsn: Ok...she's thinking...
   HaloMyBaby: People have a lot of stereotypes!
   LiveKOKO: I like drinks.
   DrPPatrsn: What kind are your favorites?
   LiveKOKO: Apple drink.
   HaloMyBaby: SickboyRE asks: Koko, have you taught other gorrillas sign
   language, on your own?
   DrPPatrsn: Good question.
   LiveKOKO: myself
   DrPPatrsn: part of that answer might be that she's taught us
   HaloMyBaby: She's really creative!
   DrPPatrsn: She's acknowledging that in that answer.
   HaloMyBaby: She makes up some of her own terms, like Lips for woman.
   DrPPatrsn: Right and foot for male.
   HaloMyBaby: Another question from the audience: Does Koko like birds?
   I have the bird t-shirt she painted -- I'm wearing it now! (Available
   for purchase at KW Heaven!).
   DrPPatrsn: She's very thoughtful today, she just walked away, she's
   looking out the window...
   HaloMyBaby: She's looking at the birds!
   DrPPatrsn: There are a number of blue jays that have been frequenting
   her play yard exactly! She's going to look at the birds!
   HaloMyBaby: Are there any birds out there now?
   DrPPatrsn: One just flew by. She expresses herself with actions. This
   is typical of young children.
   HaloMyBaby: This is a very abstract one for her: Are you content with
   your life? That was from Jedi114. I'm very curious to see what she
   might say to that! We know she might not be able to answer everything,
   but we're going for it anyway!
   DrPPatrsn: Koko, are you happy?
   LiveKOKO: fine
   HaloMyBaby: Here's one: Koko, where would you like to visit?
   DrPPatrsn: That's hard because Koko doesn't travel.
   HaloMyBaby: We were wondering about that.
   DrPPatrsn: Her concept of space is very limited even in terms of a
   child.
   HaloMyBaby: Would she like to go to Hawaii?
   LiveKOKO: Look.
   HaloMyBaby: Me too!
   DrPPatrsn: She actually has travel logs of Hawaii that she watches on
   TV.
   HaloMyBaby: Does she watch TV?
   DrPPatrsn: Only public broadcasting.
   HaloMyBaby: LOL.
   LiveKOKO: Think.
   HaloMyBaby: Storm 1004 asks: Dear Koko...I've watched you for years
   now...your gentle spirit is inspiration for many... I'd like to know
   what you'd like for your birthday.
   HaloMyBaby: What a sweet question!
   LiveKOKO: Birthday. Food and smokes.
   HaloMyBaby: SMOKES?
   DrPPatrsn: You have to understand...Smoke is also the name of her
   kitten.
   HaloMyBaby: HMBarbari: asks Koko, Have you ever tried to teach your
   kittens sign language?
   DrPPatrsn: She still has Smokey. She's looking out the window right
   now...Actually, I can tell you that she has not tried to teach them
   sign language but she has tried to nurse her kittens.
   HaloMyBaby: Wow!
   DrPPatrsn: It's very important to her. She's 310 lbs. I can't get her
   to turn around...
   HaloMyBaby: LBratt0n asks, Koko do you have an email address?
   DrPPatrsn: Koko does have an email address Koko@gorilla.org.
   HaloMyBaby: JAM6860 asks, You like your trainer alot don't you? (I
   think she means you, Dr. P!)
   DrPPatrsn: no comment...LOL. She's thinking about it. LOL.
   Question: Hi Koko, you are a beautiful gorilla. Was it hard to learn
   sign language?
   HaloMyBaby: OceanFish asked that one! I agree -- she's the most
   beautiful gorilla I know! ReBeL1999 asks, do you dream at night?
   Wouldn't it be amazing to know what a gorilla dreams!
   DrPPatrsn: I asked her this once... I had to explain it. I asked her
   if she heard, smelled, saw things. I needed to explain what a dream
   was.
   HaloMyBaby: What do you like to do best, for fun, asks TrukkasW?
   Sounds like Koko might have had enough?
   DrPPatrsn: Maybe she has...
   LiveKOKO: Hear the phone.
   DrPPatrsn: Is there anything you'd like to say, Koko?
   HaloMyBaby: We knew she might only be able to chat for about a half an
   hour...
   DrPPatrsn: She just gave a little vocalization. She wants a little
   refreshment here.
   Question: Were you real real sad when your cat died?
   HaloMyBaby: BDurant79 asked that.
   DrPPatrsn: She does remember her cat that died.
   HaloMyBaby: How long ago was that?
   DrPPatrsn: She does react with emotional words...That was in 1985.
   She's having some snacks and food here.
   LiveKOKO: lips, hurry, good, give me.
   HaloMyBaby: Lips is woman, right?
   DrPPatrsn: Right. She's got an alligator. She's playing with her
   alligator and her lady dol. Oh, my! She may be doing a little acting
   out here.
   HaloMyBaby: She sounds like she's working out a bit of aggression! I'm
   trying to get a picture of where you are, what it looks like?
   DrPPatrsn: We're in Koko's kitchen area. There are toys all around a
   refrigerator, television, stuffed animals, videos. It's got a lot of
   stuff including a harmonica but she pushed it away, doesn't wan to
   play with that. I gave her a couple of fabric bracelets... she's
   looking at them. She's putting it on her head because actually these
   are scrunchies.
   LiveKOKO: fake, hat that
   DrPPatrsn: She's pulling one of them and it's not fitting her hair.
   HaloMyBaby: Does she have hair? Or is it like fur?
   DrPPatrsn: She has hair.
   LiveKOKO: fine
   DrPPatrsn: She has fine hair. It's beautiful!
   HaloMyBaby: How big is she?
   DrPPatrsn: She's about 5 feet tall and weighs about 300-310 lbs. She
   has a big tummy!
   HaloMyBaby: Koko tell us what you look like in your words?
   LiveKOKO: flower
   DrPPatrsn: One of the scrunchies has a big flower on it.
   LiveKOKO: eat now
   DrPPatrsn: She wants some more of the snack, apparently.
   LiveKOKO: sleep, red red
   DrPPatrsn: She's indicating the red scrunchie.
   LiveKOKO: sip
   DrPPatrsn: I think it's about dinner time for her now.
   HaloMyBaby: How do you feel about Michael?
   LiveKOKO: foot, foot, good
   HaloMyBaby: foot means male, right?
   LiveKOKO: nipple
   DrPPatrsn: Remember that foot=male, right.
   LiveKOKO: good
   DrPPatrsn: She's acting out a little here.
   HaloMyBaby: What about Ndume?
   LiveKOKO: bad
   HaloMyBaby: Oh dear.
   LiveKOKO: toilet
   HaloMyBaby: Uh oh!
   DrPPatrsn: That's her word for bad!
   HaloMyBaby: I thought he was supposed to be her mate! What did he do
   to you today, Koko?
   DrPPatrsn: I don't know... she doesn't have good things to say about
   him today.
   LiveKOKO: down
   DrPPatrsn: What did he do today? He did something obnoxious that was
   obnoxious, but I didn't see what happened. Maybe they had a little
   tiff.
   HaloMyBaby: This is interesting, from the audience, not sure how you'd
   ask this: Koko, do you feel love from the humans who have raised you
   and cared for you? Ely35150 asked that. We'll see what she says!
   DrPPatrsn: She's reading a birthday card.
   LiveKOKO: lips, apple give me
   DrPPatrsn: People give her her favorite foods.
   LiveKOKO: love, browse drink nipple
   DrPPatrsn: Browse is like... the little foods/snacks we give them.
   LiveKOKO: koko loves that nipple drink, go
   DrPPatrsn: She's kissing her alligator.
   LiveKOKO: lights off good
   DrPPatrsn: That's like a closer.
   HaloMyBaby: That sounds like a good segue!
   DrPPatrsn: She makes that sign when Ron has the lights on the camera.
   HaloMyBaby: Let's let her off the hook then! Tell us that about the
   Maui preserve, what you're hoping to do?
   DrPPatrsn: Our dream is to establish a preserve, 70 acres of land
   donated on West Maui by Maui Land & Pineapple Company that would be a
   sanctuary for gorillas including Koko, Michael and Ndume. A place
   where they would be safe and would be able to raise a family.
   HaloMyBaby: Will you be able to recreate a natural family unit there?
   DrPPatrsn: We're hoping. Not only would we hav a more natural
   environment because the climate is more like Africa, but also we'd be
   able to have one male, several females and their babies.
   LiveKOKO: fake
   DrPPatrsn: The alligator is biting the lady doll...
   HaloMyBaby: What does fake mean to her?
   LiveKOKO: gorilla
   DrPPatrsn: She knows that what I'm saying hasn't happened yet.
   LiveKOKO: brown
   HaloMyBaby: She IS smart!
   LiveKOKO: bad
   DrPPatrsn: So, she's indicating that "fake" is not what she has now,
   even though I'm talking about it and the reason we haven't been able
   to make it happen yet is that we're working very hard to raise the
   money to make it happen. It will take about $7 million, and we're less
   than 1/2 way there.
   HaloMyBaby: So everyone, buy t-shirts -- every one is a donation to
   the preserve! At Keyword:Heaven after the chat!
   DrPPatrsn: We're hoping that corporations and the public will help us.
   We want Koko and her future family to share this dream. She very much
   wants to have a baby. She's indicated that this is what she wants.
   HaloMyBaby: Is she about finished, do you think?
   LiveKOKO: good, fine
   DrPPatrsn: She's now putting a comb in the alligator's mouth.
   LiveKOKO: have food lips
   DrPPatrsn: Ok. She's ready for dinner!
   HaloMyBaby: So we should say goodbye?
   DrPPatrsn: She blew a kiss!
   HaloMyBaby: Good bye and thank you Koko!
   HaloMyBaby: Thank you Dr. Patterson!
   LiveKOKO: look
   HaloMyBaby: I would be happy to come see her so she could look at me!
   LiveKOKO: hat that
   DrPPatrsn: She's playing with her alligator.
   HaloMyBaby: What will she do now when we get off the phone? What does
   she eat for dinner?
   DrPPatrsn: She'll be very pleased to have her dinner. She has raw
   vegetables for dinner. She wants to hear, but the phone cord won't
   stretch.
   HaloMyBaby: Hello Koko? (I just asked her about her dinner over the
   phone!)
   LiveKOKO: visitor, koko loves lips
   HaloMyBaby: I love her too!
   LiveKOKO: good
   HaloMyBaby: I'd like to see you some time!
   DrPPatrsn: She's playing with her troll doll now!
   DrPPatrsn: We'll sign off now!
   HaloMyBaby: Thank you and good night!
   OnlineHost: H.e.a.v.e.n. -- Helping Educate, Activate, Volunteer &
   Empower via the Net and the EnviroLink Network -- the online
   environmental community, have joined together with the Gorilla
   Foundation and AOL Live to bring you. To buy a tshirt to support
   Koko's new home, go to www.envirolink.org, or keyword: Heaven!
   OnlineHost: Copyright 1998 America Online, Inc
***************************
Here's the summary "words" used by KOKO.  See the original
transcript above for the context. For example:
Question: Do you like to chat with other people?
HaloMyBaby: That was from Rulucky!
LiveKOKO: fine nipple
DrPPatrsn: Nipple rhymes with people, she doesn't sign people per se,
she was trying to do a "sounds like..."
Could Sigmund Freud, in the Interpretation of Dreams, do any better?
1 apple
1 birthday
1 dog
1 don't
1 drink
1 drinks
1 eat
1 fake
3 fine
1 flower
1 food
1 foot
1 give
2 good
1 hat
1 hear
1 here
1 hurry
2 i
1 it
1 koko
1 like
1 lips
2 listen
1 look
1 loves
1 me
1 myself
1 nipple
1 no
1 phone
1 pink
1 see
1 smokes
1 that
1 the
1 think
1 unattention
------------------------------
39 Total number of different word types used
44 Total number of words (tokens)
0.886 Type/Token ratio
From file <koko.cha>
MLU for Speaker: *KOK:
MLU (xxx and yyy are EXCLUDED from the utterance and morpheme counts):
Number of: utterances = 23, morphemes = 44
Ratio of morphemes over utterances = 1.913*
Standard deviation = 1.213
_____
* This value, the MLU (mean length of utterance), is about that
expected for a 22 month old child. For the first 4
years, MLU correlates near 1.0 with age.