1. Develop a simple set of rules for diagnosing respiratory system diseases given patient symptoms, using the following knowledge of typical symptoms.
Influenza: Symptoms include a persistent dry cough and a feeling of general malaise.
Hay fever: Symptoms include a runny nose and sneezing. The patient will show a positive reaction to allergens, such as dust or pollen.
Laryngitis: Symptoms include a fever, a dry cough, and a feeling of general, malaise. A "laryngoscopy" will reveal that the person has an inflamed larynx.
Asthma: Symptoms include breathlessness and wheezing. If it is trigged by an allergen, such as dust or pollen, it is likely to be "extrinsic asthma". "Intrinsic asthma" tends to be trigged by exercise, smoke or a respiratory infection.
Describe how a simple backward chaining interpreter could be used to go through the possible diagnoses, asking the user questions about their symptoms.
2. What do you think are the main problems and limitations of the rule-set developed for above question 1? What additional knowledge might be useful to deal with more complex or subtle diagnoses?