Question : Which of the following is true with regards to the Apriori Algorithms? A. Algorithm starts with the combination of all the distinct item, to find the frequent itemset and in next iteration, it reduces one item from that frequent Itemset. B. Algorithm starts with one distinct item, to find the frequent itemset and in next iteration, it add one item to find the frequent itemset. C. If combination has frequent itemset than its subset will also be frequent dataset. D. If combination has frequent itemset than it does not guarantee that subset of that combination will also be frequent dataset.
1. A,B 2. B,C 3. C,D 4. A,D 5. B,D
Correct Answer : Get Lastest Questions and Answer : Explanation: In case of the Apriori algorithm, it will check the first one individual itemset like {bread}, {milk} etc. And once it finds the frequent itemset for individual than it will go for combination like {bread, milk} and increases in each iteration. However, if does not find any itemset in frequent dataset than in next iteration it will remove that combination altogether. If any combination is part of frequent dataset than its subset is also part of frequent dataset.
Question : If you have Association Rule as X->Y, which of the below represent the Confidence?
Correct Answer : Get Lastest Questions and Answer : Explanation: In an Association Rule Confidence can be defined as certainty or trustworthiness associated with discovered rule. Mathematically, confidence is the percent of transactions that contain both X and Y out of all the transactions that contain X. Hence Confidence {X->Y} is defined as Support for {X,Y}/Support for{X}. Higher the confidence means the relationship is more trustworthiness.
Question : In the Apriori algorithm which statement is true with regards to Confidence for Association Rule {X->Y}? A. It consider antecedent {X} B. It consider consequent {Y} C. It consider co-occurrence of {X,Y} D. It does not consider consequent {Y} E. Confidence cannot tell if a rule contains true implication of the relationship of if the rule is purely coincidental.
Correct Answer : Get Lastest Questions and Answer : Explanation: Using confidence we can identify the interesting rules from all the candidate rules, it comes with a problem. Given rules in the form of X -> Y, confidence considers only the antecedent (X) and the co-occurrence of X and Y; it does not take the consequent of the rule (Y) into concern. Therefore, confidence cannot tell if a rule contains true implication of the relationship or if the rule is purely coincidental.