UOTC Apriori Property and Binary Variables Questions 1. What is the Apriori property? 2. Following is a list of five transactions that include items A, B,
UOTC Apriori Property and Binary Variables Questions 1. What is the Apriori property?
2. Following is a list of five transactions that include items A, B, C, and D:
Tl: {A, B, C}
T2: {A, B}
T3: {B}
T4: {A, C}
TS: {A, C, D}
Which itemsets satisfy the minimum support of 0.5?
(Hint: An item set may include more than one item.)
3. How are interesting rules distinguished from coincidental rules?
4. A local retailer has a database that stores 10,000 transactions of last summer. After analyzing the data, a data science team has identified the following statistics:
{battery} appears in 4,000 transactions.
{sunscreen} appears in 3,000 transactions.
{sandals} appears in 4,000 transactions.
{bowls} appears in 1,000 transactions.
{battery, sunscreen} appears in 1,500 transactions.
{battery, sandals} appears in 1,000 transactions.
{battery, bowls} appears in 1250 transactions.
{battery, sunscreen, sandals} appears in 600 transactions.
Answer the following questions:
a. What are the support values of the preceding itemsets?
b. Assuming the minimum support is 0.05, which itemsetsare considered frequent?
c. What are the confidence values of {battery}->{ sunscreen} and {battery, sunscreen}->{ sandals} ?
d. Which of the two rules is more interesting?
5. In the use of a categorical variable with n possible values, explain the following:
a. Why only n – 1 binary variables are necessary
b. Why using n variables would be problematic
6. If the probability of an event occurring is 0.4, then
a. What is the odds ratio?
b. What is the log odds ratio?
