Observation is related to Watch. Watch is a synonym of Attention. 
Age is related to Iron. Iron is related to Implement. Implement is a type of Device. Device can be used for Purpose. 
Observation <--RelatedTo--> Watch <--Synonym--> Attention 
Age <--RelatedTo--> Iron <--RelatedTo--> Implement --IsA--> Device --UsedFor--> Purpose 