Scenejo, a dialogue based system using chat bots, makes use of so-called SREs (Stimulus Response Elements) that - like the name implies - are made up of a stimulus (what the bot is hearing) and a response (what a bit is answering) to that stimulus. To achieve a higher variability not only one answer is possible and answers may have (pre-)conditions and/or effects.
The figure below shows a screenshot of a part of an SRE. It consists of one condition, one output and one effect.
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Taking a closer look we find the condition is made up of:
- a variable (predicate), that can be chosen from a pool of the predicates an actor has attached
- a relational operator (for example: <, >, <=, >=, ==) to compare the value of the variable during runtime with the in the following defined one
- a value (that has to be of the same type as the predicate)
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That means, that every time the bot “hears” a certain input that belongs to this SRE, the condition is checked and if it is true (the value is 0 or negative) the following output is given as an answer and the effect operation will be computed. Otherwise the system will check the next condition(s) (ELSE IF) until it reaches the ELSE in the end, which defines the answer to everything that was not covered by the prior conditions.
An effect may be one or multiple operations. The following figure shows an example.
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Similar to the condition an effect is made up of:
- a variable (predicate), that will be modified
- an arithmetic operator (for example: +, -, *, /)
- a value (that has to be of the same type as the predicate)
That means that additional to the given answer a predicate is modified, in this case the MOOD is lowered by 1 (MOOD := MOOD - 1).
It is also possible to use not only one simple, but multiple complex conditions. The figure below shows one example.
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By using the logical connectives conjunction (AND) and disjunction (OR), multiple conditions can be combined to create a more selective case. In the given example the answer will only be given if the dark or light blue marked conditions are true. The dark and light blue conditions are themselves made up of two conditions combined by an AND, so each of them has to be true.
Examples:
MOOD := -2 and ASSERTIVENESS := 0.4 --> true MOOD := -2 and ASSERTIVENESS := 0.6 --> false MOOD := 5 and ASSERTIVENESS := 0.6 --> true MOOD := 2 and ASSERTIVENESS := 0.6 --> false
