Chapter 5 IS 335

Platinum Gym has 10,000 gym members, out of which 1,500 memberships include unlimited fitness training and use of the tanning salon, and 750 include unlimited hydromassage. If fitness training is considered A,use of the tanning salon is considered B, and hydromassage is considered C, then the associate rule for these sales becomes "If A and B are purchased, then C is also purchased." Given total transactions for C = 3000, calculate the lift for this rule.

1.67

_____ analyzes items frequently co-occurring in transactions (such as purchases).

Market basket analysis

Interpret the following association rule: "if {ground beef, cheese}, then {taco shells}."

This means that if a transaction includes ground beef and cheese, then it also includes taco shells.

_____ is the process of dividing text into separate terms known as tokens.

Tokenization

Confidence can be viewed as a conditional probability of the consequent item set occurring given that the

antecedent item set occurs.

Complete linkage defines the similarity between two clusters as the similarity of the pair of observations (one from each cluster) that _____.

are the most dissimilar

There are infinitely many possible association rules for transaction data. To simplify, we only consider association rules with a support count of

at least 20% of the total number of transactions.

Identify the antecedent of the following association rule: "if {cereal}, then {milk}."

cereal

The _____ clustering method defines the similarity between two clusters as the similarity of the pair of observations (one from each cluster) that are the most different.

complete linkage

The item set corresponding to the "then" portion of an if-then association rule is called the

consequent.

Analysis of items frequently co-occurring in transactions (such as purchases) is known as lift.

false

Complete linkage is a measure of calculating dissimilarity between clusters by considering only the two closest observations in the two clusters.

false

_____ assigns each observation to one of k clusters in a manner such that the observations assigned to the same cluster are as similar as possible.

k-means clustering

In a data set, data may be missing for several reasons. If the reason that the values are missing is related to the value of the variable, then the missing data is said to be

missing not a random

Single linkage is a measure of calculating the distance between two clusters by considering only the two _____ observations between the two clusters.

most similar

Euclidean distance can be used to measure the distance between _____ in cluster analysis.

observations

If the Euclidean distance were to be represented in a right triangle, which of the following would be considered the distance between two objects of a cluster?

the hypotenuse

Marketers are interested in examining transaction data on customer purchases to identify

the products that are commonly purchased together.

Association rules convey the likelihood of certain items being purchased together.

true

Centroid linkage uses the averaging concept of cluster centroids to define between-cluster similarity. True

true

Euclidean distance is the most common method to measure dissimilarity between observations.

true

If the support of the consequent is high, the confidence of the association rule could be high even if there is little or no association between the items.

true

Text data is often referred to as unstructured data because in its raw form, it cannot be stored in a traditional structured database.

true

The efficiency of an association rule, known as lift, is determined by the ratio of the confidence of an association rule to the benchmark confidence.

true

The goal of unsupervised learning is to use the variable values to identify relationships between observations.

true

The item set corresponding to the "if" portion of an if-then association rule is called the antecedent.

true

Identify the consequent of the following association rule: "if {jello, pudding}, then {whipped cream}."

whipped cream

Platinum Gym has 10,000 gym members, out of which 1,500 memberships include unlimited fitness training and use of the tanning salon, and 750 memberships include unlimited hydromassage. If fitness training is considered A, use of the tanning salon is considered B, and hydromassage is considered C, then the associate rule for these sales becomes "If A and B are purchased, then C is also purchased." Calculate the confidence

.5

_____ is bottom-up clustering that starts with each observation belonging to its own cluster and then sequentially merges the most similar clusters to create a series of nested clusters.

Hierarchical clustering

A collection of text documents to be analyzed is referred to as _____.

a corpus

Ward's method merges two clusters such that the dissimilarity of the observations within the resulting single cluster increases _____.

as little as possible

The goal of _____ is to segment observations into similar groups based on the observed variables.

clustering

The number of times that a collection of items occurs together in a transaction data set is known as the sampling.

false

The lift ratio demonstrates some usefulness to the association rule if its value is

greater than 1

The _____ the lift ratio, the _____ the association rule.

higher, stronger

Which of the following explicit measures does not help to filter association rules?

lift ratios

Centroid linkage uses the averaging concept of cluster centroids to define between-cluster similarity.

true

Complete linkage is a measure of calculating dissimilarity between clusters by considering only the two most dissimilar observations in the two clusters.

true

Euclidean distance can be used to measure the distance between two observations, each consisting of two variable measurements.

true

The lift ratio of an association rule with a confidence value of 0.27 and in which the consequent occurs in 4 out of 10 cases is 0.675.

true