After completing a query, Rainbird will create an evidence tree and display fact cards about the decisions made for all relationships, rules and expressions Rainbird has used to complete the query. By default, Rainbird will populate the fact cards using the relationship and subject names as they are stored in the knowledge map. The information presented in the evidence tree can be changed, to improve the readability and accessibility of the evidence tree, by ‘debugging expressions’ and using ‘traversing’ alt text.
Before we can use alt text, we need a knowledge map. The knowledge map below is a map that determines whether a person can successfully access and log in to an account. To be able to access the account, a person enters their National Insurance Number and Rainbird will check if there is an existing account registered with the same National Insurance Number. The rule to return a successful/unsuccessful result sits under the ‘access account’ relationship.
Figure 1: Example ‘account login’ knowledge map
After running the query, the evidence tree displays the different Subjects, Objects, relationship names and expressions used by Rainbird to determine the result:
Figure 2: Evidence tree without alt text
The wording used in the evidence tree matches the wording in the conditions:
Figure 3: rule condition
As a rule could run through several complex relationships and expressions to return a result, the information in the evidence tree might not always be easy to understand by an end-user. To improve the user experience by making the information in the evidence tree easier to understand, the alt text feature can be used to define the information for any rule, relationship or expression displayed by Rainbird in the evidence tree.
For example, to return ‘Dan user access successful’ rather than the result displayed previously, the alt command, ‘{{%S}} User access {{%O}}’ needs to be inserted into the alt text option of the appropriate rule (see Figure 4). Square {{ }} brackets with %S or %O between them are used to insert the subject i.e ‘Dan’ and the object i.e. ‘successful’ into the alt text generated by Rainbird
Figure 4: Alt text option of a rule
On top of the altering the rule outcome text, each of the condition and condition expressions text can also be changed, individually:
Figure 4: Alt text option of conditions
On re-running the query, the evidence tree would now display “Dan User access Successful” instead of “Account Dan Access Account Login Successful”:
Figure 6: Evidence tree using alt text
The traversing relationship feature enables us to add additional information to a subject or object connected via a relationship and a Concept Instance when reviewing the evidence tree.
Continuing with the “account login” example above, the map has been expanded to add the concept ‘Gender’ and two concept instances for Gender, male and female. A fact has been created between ‘Dan’ and ‘Gender”: DAN has gender MALE’
Figure 7: ‘Dan’ has gender ‘Male’
In the rule alt text option, the Subject is linked via the Relationship by %VARIABL.name of relationship – in our example, %S.has gender:
Figure 8: “Traversing” alt text added
The result will display ‘male’ in the evidence tree:
Figure 9 Evidence tree using “traversing” alt text
- If a variable subject or object has multiple instances, all would be displayed in the evidence tree.
- “Traversing” alt text can also be linked to facts generated at runtime.
The RBLang below will generate the map that was built in the article. Click on ‘Export .rbird’ to download the knowledge map, or ‘copy RBLang’ and paste the code directly into Rainbird.
Query and Results
