Talkback is an educational game inspired by a famous computer program called ELIZA in which users held 'conversations' with the computer by typing in sentences, and the program responded by displaying sentences that were apparently replies.

Talkback also allows users to create their own computer 'characters' capable of holding simple conversations on the screen. This process is both entertaining and demanding, providing valuable lessons in both English and computer literacy.

Users may observe the conversation, print it out or even join in!

For anyone aged 10 years and above.

Talkback allows users to create their own computer 'characters' by building and developing sequences of Keywords, Responses and Starters. Users can watch, print out and even join in their characters' conversations on the screen. Characters can be saved on tape or disc at any stage and reloaded for further development later.

Talkback is a tool for manipulating language, an entertaining educational game and, perhaps, a form of programming. Users have the chance to develop their understanding of language and discover what microcomputers can, and cannot, do with words. They can either experiment or, with careful attention, achieve controlled results. Such attention to detail can be compared with simple programming, and the 'program', consisting of Keywords, Responses and Starters can be RUN whenever dialogues are tried out.

Talkback encourages observation and offers scope for the imagination. Once the techniques described in this booklet have been practised, Talkback will become an interpretive tool that can be applied to many real and imagined situations. Possibilities include dialogues drawn from life: interviews, 'phone calls, complaints, proposals and doorstep selling. More imaginative dialogues might include: a car and horse, stomach and mouth, the new year seeing the old year old or a close encounter with an alien!

Talkback starts on the 'Choice page'. There are six options:

1. Create or alter a character
2. Load a character
3. Drop a character
4. Save a character
5. Start dialogue
6. End the program

ESCAPE will always return you to this page.

You may wish to begin by loading the two sample characters provided with the program and then starting a dialogue. Option 2 allows you to load characters.

One of the sample character files provided with Talkback is called BOMB, inspired by the concluding part of the film (and book "Dark Star"). The companion character is ASTRO.

Load ASTRO and BOMB as characters A and B. Follow the screen instructions and/or refer to the section 'Loading and saving files' in this booklet.

When both characters have been loaded press 5 on the 'Choice page' to select 'Start dialogue'. You will then be offered three dialogue options:

1. ASTRO and BOMB
2. ASTRO and you
3. BOMB and you

You will probably want to try all three. Options 2 and 3 allow you to decide who will be the first speaker. After choosing you will be asked to type in your name and press RETURN. Then you will be given the option to print out the dialogue. (If you select this option without a printer attached, your computer will wait while you do out and buy one - or until you press ESCAPE to return to the 'Choice page'.)

If you selected a dialogue between one of the characters and you there will be a reminder at the bottom of the screen to "Press ESCAPE for Choice page". If you selected a dialogue between two characters you will see the following options:

1. Restart
2. Choice page
3. Join in

To select these: press and hold down the appropriate key until the conversation is interrupted. Dialogue speed can be adjusted by pressing the left or right arrow keys.

Every Talkback character has a list of things to say called Responses. Each Response has an associated Keyword. A Response may appear only when its Keyword matches something that another speaker has said.

After thoroughly trying out ASTRO and BOMB on the 'Dialogue' page you may wish to switch from the 'Choice page' to the 'Create/alter' section by selecting option 1. Then press 3 to see the 'Keywords and Responses' section. The left and right arrow keys, and number key 2, will allow you to examine the Keywords and Responses of ASTRO and BOMB.

You can begin to create your own characters by pressing ESCAPE to return to the 'Choice page'. If you have, for instance, already loaded ASTRO and BOMB into the program you will need to remove one or both before entering new characters. Select option 3 'Drop a character' to begin this procedure. After entering the appropriate letter you will be returned to the 'Choice page'. (Repeat this procedure if you wish to drop both characters.)

You may now select option 1 'Create or alter a character' from the 'Choice page'. On the 'Create/alter' page you will be given the opportunity to type in the name of either character (maximum seven letters) by selecting option 1 or 2. Enter HELEN and RON as characters A and B if you'd like to use a brief example conversation.

The Create/alter menu presents four options:

1. Character A: HELEN
2. Character B: RON
3. Keywords and Responses
4. Starters

Option 4 will take you to the 'Starters' section, where up to four Starters can be entered for each character.

Starters are the lines of dialogue with which characters start conversations (e.g. "I'm glad I've found you"). Starters are also used when no Keyword match can be found to trigger a Response. Each character requires at least one Starter. One character's Starters should contain Keywords that the other will recognise.

Options will be displayed in the lower part of the screen:

1. Keywords/Responses
2. Other character
3. Add a Starter
4. Change Starter
5. Delete Starter

You could give HELEN and RON one short Starter each:

Select option 3 'Add a Starter'. Type the Starter then press RETURN. Option 2 will allow you to type in the other character's Starter.

When you have completed the Starters: Select option 1 to go to the 'Keywords/Responses' section where the linked pairs of Keywords and Responses can be entered for each character (Note: you can also reach this section from the 'Choice page' by selecting option 1 'Create/alter', then option 3 'Keywords and Responses').

Options will be displayed in the lower part of the screen.

The following simple conversation offers some variety in the Responses to particular Keywords:

The options in the lower part of the screen are similar to those offered in the 'Starters' section. Select option 3 to add the first pair of Keywords and Responses. When this pair has been entered you can add another. You may either enter one pair for character A and then another for character B (option 2), or enter all the Keywords and Responses for one character first. You can use the left and right arrow keys to look through the Keywords/Responses list of the character you are working on. Options 4, 5 and 6 allow you to alter the list of Keyword and Response pairs.

Press ESCAPE to return to the 'Choice page', then select option 5. On the 'Dialogue' page you will be given the option of three dialogues:

1. HELEN and RON
2. HELEN and you
3. RON and you

If you select option 1 at this stage you will still be able to join in during the conversation. When participating in a dialogue the lines you type in will need to include words that the other characters will recognise as Keywords to trigger their Responses.

When you have seen how this conversation progresses you may wish to experiment by adding more Starters or Keywords and Responses. The next section of this booklet provides examples for developing more sophisticated dialogues.

This example demonstrates how two Talkback characters might conduct a dialogue on the telephone. One character SPY is attempting to arrange a rendezvous - and thinks CALLER is another spy.

CALLER can respond to 123007 and talk with the following:

SPY can respond to 123000 and Kay with the following:

The two characters can now begin a basic dialogue. If you try this you will find that one of the major themes of the conversation is concerned with 'number', while other possibilities include 'Kay' and 'talk'.

When SPY says "Can we talk", CALLER responds with "Do I have the right number". This Response can be varied by including another Response to the Keyword talk:

CALLER now has two Responses to the Keyword talk. "This must be a bad line" does not contain a Keyword which SPY will recognise, so SPY must reply with a Starter.

SPY and CALLER can be made to respond to number with the following additions:

The number of SPY's Responses to the Keyword kay can also be increased:

SPY now has three Responses to the Keyword kay. "Who did you say" does not contain a Keyword which CALLER recognises, so CALLER must reply with a Starter. "You are talking to 123007" contains two Keywords: talk and 123007. Talkback will select 123007 in preference to talk because 123007 appears earlier than talk in the list of Keywords that CALLER will recognise.

An additional Starter for each character will produce more variety:

The words identify and identified appear in two of SPY's Responses. The Keyword identif, which should be typed with no spaces after the 'f', will match with both words:

The second identif Keyword, with its different Response, produces more variety.

At this stage the dialogues between CALLER and SPY follow several themes; they involve questioning and answering and, of course, talking at cross-purposes.

CALLER's replies to SPY can be made more realistic by using stems - a special form of Keywords. An asterisk typed after a Keyword indicates that it is a stem. Stems allow the final part of one character's Response to be repeated as the final part of the other character's Response. In addition, words such as you, are and I've will be replaced by me, am, you've, etc when parts of Responses are repeated.

SPY has one Starter and two Responses that include the Keyword number. Two of these: 'What is your code number' and 'What is your number' contain the phrase 'What is' - suitable for a Keyword stem. Two Responses based on this stem will provide more variety.

However, the what is stems must appear earlier than the Keyword number in CALLER's list of Keywords/Responses if they are to be recognised:

CALLER's what is* stem bounces any questions about number back to SPY. Consequently SPY needs more Responses to the Keyword number.

At this stage the characters contain three Starters, Keywords and Responses:

The following table of Keywords indicates the number of times each Keyword will be recognised in the other character's Responses and Starters. This can be compared with the number of Responses each Keyword gives:

Four of the Responses deliberately do not contain Keywords. These are:

When Talkback encounters one of these of these it will look for a Keyword in the character's previous Response. If a match still cannot be found Talkback produces a Starter instead. Starters are also used (in situations where only one Response is available) to avoid the same Response appearing twice in succession. Starters can be used to add an additional element of unpredictability to dialogues.

CALLER and SPY now have a core of dialogue around which more complex conversations can be built. Each has a spare Starter available and more Keywords (particularly stems) are needed. Links can be made by adding extra Responses, containing new Keywords, to existing Keywords such as 123007 or 123000. Existing Keywords could be replaced, Responses modified and new dialogue included to reveal more of the intentions and attitudes of CALLER and SPY.

CALLER's three Responses which do not contain Keywords can be drawn upon to provide new Keywords: line, who and 1230007. SPY will respond to these by trying out passwords (containing a stem which CALLER recognises). CALLER's Responses will not contain any Keywords so the route back to a Starter will merely be lengthened.

SPY's Response which does not contain a Keyword can be drawn upon to provide a new Keyword who and begin the closing sequence. CALLER gives, or stumbles upon, the password OK, SPY introduces the message, gets CALLER's attention and then delivers one of two messages. CALLER will then either hang up in disgust or respond appropriately: allowing SPY to arrange the rendezvous and then hang up. If one character hangs up then the other does too, and only the dialling tone will remain.

The line of dots is built up from a pair of full stops with a space between them. More than one full stop is necessary to distinguish it from standard punctuation, and the space between them balances the space Talkback inserts in Responses when dealing with stems. The line of dots is a long Keyword made with alternate dots and spaces. Its function is to reduce the growing line of dots to only two dots. The line of dots grows because whenever dot-space-dot (i.e. the stem) is recognised in a Response this will be replaced by dot-space-dot-space-dot in the following Response.

You can have a lot of fun creating unusual characters and situations with Talkback. Perhaps by recreating incidents - fact or fiction - you've seen or read about. Even everyday occurences can become fascinating. Would you like to see some of the conversations develop differently? Do some people have particular ways of speaking? What happens if you get involved and say what you feel about the whole thing?

Here are a few suggestions for situations and characters on which you might like to base a conversation:

1. In a restaurant
2. A hole in the road
3. Interview for a job
4. Late for school or work
5. Buying a second-hand car
6. A politician is interviewed
7. Returning faulty goods to a shop
8. Meeting for the first time at a party
9. The head of a delegation from the Hastings Tourist Board welcomes William the Conqueror as he steps ashore
10. King Henry the Eighth goes to a present day marriage guidance counsellor
11. A Wimbledon umpire and tennis professional have a slight disagreement! Could you help out?

You might have a pair of characters who do nothing but ask each other silly riddles. For example:

For this kind of exchange one character would need a list of first lines e.g. 'Why does a cow wear a bell?' containing Keywords eg. bell and a list of punchlines eg. 'Because its horns don't work' to be produced when the appropriate Keyword is recognised. The other character would contain Keyword stems which look for questions such as Why, What, How and so on, and respond with 'I don't know - Why (or What, or How) ...

Loading files
From the 'Choice page' select option 2 'Load a character'. On the 'Load' page you will be asked if you wish to load character A or B.

Note: Only Talkback files should be loaded into the program. If you attempt to load a non-existent or incorrectly named file, the screen will display the message:

Not Found. Press SPACE BAR to continue.

You will then be returned to the 'Choice page'.

Saving files
From the 'Choice page' select option 4 'Save a character'. On the 'Save' page you will be asked if you wish to save character A or B.

Note: If you attempt to save a non-existent character the screen will display the message:

That can't be used please try again
Press SPACE BAR to continue

You will then be returned to the 'Choice page'.

Restarting the program
If you press the BREAK key then Talkback, with any characters, will be cleared from the computer's memory. If, however, you select option 6 'End the program' from the 'Choice page' you can rejoin Talkback with its characters intact by entering the following commands:

It is also possible, after selecting option 6 'End the program', to rejoin Talkback without its characters by simply typing:

Printout
Talkback's printout facility enables dialogues to be printed on paper as well as viewed on the screen. If your printer requires special commands for use with your computer these should be typed in before Talkback is loaded and run.

The following short program loads a character file and produces a printout of all the character's Keywords, Responses and Starters.

Keyword order
During conversations Talkback checks through the lists of Keywords in the order that they appear in the Keywords/Responses section. Each Keyword is compared in turn with all the words from the last Response until a match is found. Where the same Keyword has been paired with more than one Response the choice of Response will be made at random.

With this priority system it is important that you enter your most important Keywords first oj the 'Keywords and Responses' section. If, for instance, you have created a character who is interesting in sailing, it would be a good ide to enter the Keyword boat before most others. That would probably lead to a more relevant Response to 'I'd rather travel in a place than a boat', where plane was also a Keyword. Sometimes it may be useful to write Keyword and Response pairs on small cards which can be shuffled into order before they are typed in.

Stems
Stems are a special kind of Keyword. They are indicated with an asterisk after the Keyword: e.g. can you*.

If you include can you* as a Keyword, with the Response, 'Perhaps I can then', during a conversation, if one character says 'Can you tell me the time' ? the Response will be 'Perhaps I can tell you the time'.

The 'trailing text' (e.g. 'tell me the time') has been added to the Response, and you will notice that Talkback has automatically changed me into you. Whenever stems are used, it will change me to you, and vice versa. If you wish to discover what other words will be exchanged select option 6 on the 'Choice page' to end the program and then type LIST and press RETURN. The last lines of the program contain the pairs of words that will be change.

Note: I will be changed to you, but not vice versa.

Refer to the section 'Additional information' to restart Talkback.

Example stems
For your own characters, you may like to experiment by including some stems and Responses such as these:

Keyword matching
After Keywords have been entered in the 'Create/alter' section they are automatically converted to lower case (small letters) with the exception of the words 'I', 'I'm', etc. Matches may be made when the word (or words) of one character's Keyword occurs in the other character's Response. Matches are made regardless of whether the words found in the Response are in upper case, lower case or a mixture of the two.

Care is needed with any Keyword which is a shorter or longer version of another. If, for example, the Keyword 'you are' appeards before 'you are not' in the list of Keywords, the computer will never reach the second Keyword because it has already found a match. If the longer Keyword appeared first this would not happen.

If your Keyword does not end with a space, a match will be recognised in any word that begins with the letters of the Keyword, so that 'die' will match with 'die' and also with 'died'. If you wish to avoid this, simply include a space at the end of the Keyword by typing the Keyword, tapping SPACE once and then pressing RETURN. The same procedure applies to Keyword stems, where the space should be inserted before the asterisk I'm *.

Punctuation
When creating Responses for characters, or joining in a conversation, it can help if you either avoid punctuation marks (other than apostrophes and hyphens) or leave a space before following a word with a punctuation mark, eg. Why ? rather than Why?. In practice Talkback generally copes, but cannot recognise examples such as me?. This may result in it responding to a sentence such as 'Why don't you tell me?' with 'I don't want to tell me?'.

Repitition
If a character's Response would be the same as its last one a further search is made for a match. If no match is found, or a Response would still duplicate the last one, Talkback looks for a Keyword match in the other character's second-to-last Response.

Starters
If no new Response is available, a Starter will be displayed instead. A Starter will also be used if no Keyword has yet been recognised in the course of the conversation. (Note: Starters are selected at random and will sometimes be repeated.)

Number of Keywords/Responses
The example characters ASTRO and BOMB have 42 pairs of Keywords and Responses each. This is normally the maximum that Talkback can contain, but BBC Microcomputer owners with a 6502 Second Processor will be able to create up to 121 pairs of Keywords and Responses for each character. The maximum number of Starters available will always be four per character.

Changing keywords
There is a way to change a Keyword without having to retype its Response. In the 'Keywords/Responses' section, select option 4 'Change a pair', type the new Keyword and press RETURN. Then press the ESCAPE key to return to the 'Choice page'.

Closing sequence
Rather than simply interrupting a conversation yourself, you may prefer to give each character pairs of Keywords and Responses which end the dialogue with a continuous loop of appropriate farewells etc. We can use HELEN and RON to illustrate this closing sequence. The opening Keyword and Response link into the brief conversation used previously and you may wish to enter the two sequences together to view the overall effect.

Talkback designed by Daniel Chandler and David Butler.
Programmed by Rik Bean.