Handy Examples
Frequently Used Recommendation Rules
For the following examples, assume a decision named decision_1 with three candidates: candidate1, candidate2 and candidate3.
- Recommendation rule for recommending candidate1 if it is supported:
netsupport(decision_1, candidate1) >= 1 - Recommendation rule for recommending candidate1 if none of the other candidates are supported:
netsupport(decision_1, candidate2) < 1 AND netsupport(decision_1, candidate3) < 1
- Recommendation rule for recommending candidate1 if it has the highest net support:
netsupport(decision_1, candidate1) > netsupport(decision_1, candidate2) AND netsupport(decision_1, candidate1) > netsupport(decision_1, candidate3)
Diagnosis Decision
In the Cold and Flu Guide sample, a Diagnosis decision is made between the options of cold and flu. The decision is based on the table below.
| Symptoms | Cold | Flu |
| Fever | Rare | Characteristic, high (102-104F) |
| Headache | Rare | Prominent |
| General aches, pains | Slight | Usual; often severe |
| Extreme exhaustion | Never | Early and prominent |
| Stuffy nose | Common | Sometimes |
| Sore throat | Common | Sometimes |
| Cough | Mild to moderate | Common; can become severe |
| *Nasal spray flu vaccine contains weakened flu viruses and can occasionally induce flu | ||
The Diagnosis decision has three candidates:
- Flu
- Cold
- Other
Flu
The arguments for flu can be divided into 3 groups:
- Arguments that provide some support (i.e., arguments for):
- Severe cough
- Recent nasal spray flu vaccine
- Extreme exhaustion
- General aches and pains
- Headache
- Confirming arguments:
- Fever
- Excluding arguments:
- No fever
Recommendation Rule:
netsupport(DiagnosisDecision, Flu) >= netsupport(DiagnosisDecision, Cold) AND netsupport(DiagnosisDecision, Flu) >= 1
The recommendation rule for flu states that flu would only be recommended if two conditions are met:
- Net support for flu is higher than or equal to 1 – meaning there’s at the very least some argument for flu.
- Net support for flu is higher than or equal to the net support for cold – meaning there’s some argument for both, but more support for flu.
Cold
The arguments for cold can be divided into 2 groups:
- Arguments that provide some support (i.e., arguments for):
- Mild to moderate cough
- Runny stuffy nose
- Sore throat
- Arguments that are somewhat against (i.e., arguments against):
- Extreme exhaustion
- Headache
- Fever
Recommendation Rule:
netsupport(DiagnosisDecision, Cold) >= netsupport(DiagnosisDecision, Flu) AND netsupport(DiagnosisDecision, Cold) >= 1
The recommendation rule for cold states that cold would only be recommended if two conditions are met:
- Net support for cold is higher or equal to 1 – meaning there’s at the very least some argument for cold.
- Net support for cold is higher or equal to the net support for flu – meaning there’s some argument for both, but more support for cold.
Other
The Other candidate has no arguments.
Recommendation Rule:
netsupport(DiagnosisDecision, Flu) < 1 AND netsupport(DiagnosisDecision, Cold) < 1
This rule states that the Other candidate is only recommended if the net support for the other two candidates is less than 1. So it is only recommended if there’s no support for either cold or flu.
Referral Decision
The decision has three candidates:
- Two week referral
- Non urgent referral
- No referral
Two week referral
Arguments for Two week referral:
- Nipple retraction or distortion
- Eczema
- Skin distortion
- Skin nodule
- Skin ulceration
- Discrete lump in a woman over 30
Recommendation rule:
Netsupport( Referral_decision_breast, Two_week_referral ) >= 1
According to this rule, if any of the above arguments are true, a two-week referral is recommended.
Non urgent referral
Arguments for Non urgent referral:
- Asymmetrical nodularity
- Intractable pain
- Nipple discharge in a patient over 50
- Large volume, bilateral nipple discharge
- Bloodstained nipple discharge
- Abscess
- Cyst
- Discrete lump in a patient under 30
Recommendation rule:
Netsupport( Referral_decision_breast, Non_urgent_referral ) >= 1 AND netsupport( Referral_decision_breast, Two_week_referral ) < 1
According to this rule, if any of the above arguments are true and if there is no support for a two-week referral, a non-urgent referral is recommended.
No referral
The No referral candidate has no arguments.
Recommendation rule:
Netsupport( Referral_decision_breast, Two_week_referral ) < 1 and Netsupport( Referral_decision_breast, Non_urgent_referral ) <1
This rule states that if a two-week referral and a non-urgent referral are not supported, no referral is recommended.