What are Association Rules in Data Mining?


The evolution of humans from coal mining to data mining holds immense contributions to human growth and technological development. Changing the extent of physical work involved, the weight has now shifted towards mental exertion to perform this new type of mining. The data mining process includes multiple aspects, including the Association rule, which is significant due to its practical contribution to understanding the customers and driving business growth. Do you have the exact requirements? Are you interested in enhancing your knowledge to bring an exponential rise in customer satisfaction? Are you aiming to develop a better recommendation system competitive enough with big brand names? Here is a brief introduction to key concepts and fundamentals of association rules in data mining.

Learning Objectives

  • Comprehend the essence of association rules as if/then statements revealing relationships within data.
  • Identify and differentiate applications such as market basket analysis, fraud detection, and recommendation systems, showcasing association rules’ versatility and practical significance.
  • Gain insight into how association rules work, exploring the role of cardinality, support, confidence, and lift in predicting and evaluating relationships within datasets.

What Are Association Rules in Data Mining?

Defined by their names, association rules are if/then statements that identify the relationships or dependencies between the data. With the characteristic property of suiting numeric and non-numeric categorical data, it is often applied in market basket analysis and other applications. It can uptake data from relational and transactional databases and other data sources.

The association rule has two parts: antecedent or if and consequent or then. The antecedent is the first part available in data, while the resulting is the resultant part available in combination with the antecedent. For instance, the example of market basket analysis will be: “If a customer buys running shoes, then there is a likelihood that they will also buy Energy bars.” here, running shoes are antecedent, and energy bars are consequent. The example more particularly targets the fitness enthusiast audience.

What Are Use Cases for Association Rules?

There is a wide variety of applications for association rules. The top three association rule mining examples are:

Market Basket Analysis: An example of a shopping combination can be a purchase of yogurt, and granola is likely to be associated with purchasing berries. It indicates the significance of the association rule in analyzing purchasing habits and requirements. The practical usage of interpretation is seen in developing suitable combination offers, optimizing product placements, and increasing sales.

Fraud Detection: Here, the combination of use is identifying a purchase pattern, its location, and frequency. Recognition of the same helps flag fraudulent activities and take preventive measures from the same IP address.

Recommendation systems: These include detecting the usage patterns from browsing history and previous purchases to predict the future requirements of the user. The recommendations are based on the same. Expanding the usage from marketing is significant in music and shows-based services as well.

 Alt-text: Applications of Association Rule

Source: Dataaspirant

How Do Association Rules Work?

The prediction in the association rule explained previously with examples, is calculated based on cardinality, support, and confidence. Cardinality refers to the relation between two items, which proportionally increases with the number of objects. The support indicates the frequency of the statements, and then the confidence informs the frequency of truthfulness of these relationships. Explain the association rules work by determining the rules governing the reason and situation where the combination may occur. For instance, the preferred healthy and less time-consuming breakfast option combines yogurt with granola and berries.

Often, in practical situations, the numbers get unrealistic. Some statistically independent items with the least purchase combination might come together with a significantly high percentage in practical usage. For instance, statistically, lesser chances of combined purchase of beer and diapers occur while real-world statistics are comparatively higher. The increase in statistics is a lift.

Measures of the Effectiveness of Association Rules

The effectiveness of association rules is primarily measured by support, confidence, and lift. The support refers to the frequency, and the high support indicates the commonness of quantity in the dataset. The confidence measures the reliability of the association rule. The high confidence suggests A and B are proportional and hence increases in direct relation to each other.

Lift compares the dependency of the item. If the statistical and practical numbers are the same or the antecedent and consequent are the same, the lift will be 1, and the associated objects are independent. The objects depend on each other if lift > 1 and the antecedent is greater than the consequent. Moreover, the combination negatively impacts each other if the consequent is more than the antecedent with lift < 1.

Rule Evaluation Metrics

Source: Data Mining Map

Association Rule Algorithms

Three algorithms generate association rules. These are stated as follows:

Apriori Algorithm

The association rules in the apriori algorithm are generated through frequent transaction datasets. Often used for market basket analysis, it uses techniques like Breadth-first search and Hash tree. Providing the information on combined products bought together, it also serves medical purposes by finding drug reactions for patients.

Eclat Algorithm

Also known as Equivalent Class Transformation, it uses a depth-first search technique. Providing quick and accurate execution, it also deals with transaction databases. The ELCAT algorithm uses less storage and works without repeated scanning of data for computing the individual support values. Instead, it uses transaction ID Sets or Tidsets for computation purposes.

F-P Growth Algorithm

Referred to as Frequent pattern growth, it is a further enhanced version of the Apriori algorithm. It is analyzed through two steps. The first is database conversion into a tree structure, thus earning the name due to the depiction of frequent patterns. The second step is the representation format, which further eases extracting the most frequent patterns.

Association Rule Mining Technique

Source: ResearchGate


Data mining refers to extracting information from comprehensive sourced datasets. Association rule mining is the method for identifying the correlations, patterns, associations, or causal structures in the datasets. With the immense scope of applicability in retail, healthcare, fraud detection, biological research, and multiple other fields, the association rule works through the if/then statement. Support, confidence, and lift play critical roles in evaluating its effectiveness. Moreover, the development of the association rules occurs through three algorithms. Please introduce yourself to more important concepts along with association rule learning in data mining in detail with our data science course.

Key Takeaways

  • Association rules find practical use in diverse fields, such as optimizing product placements in market basket analysis, flagging fraudulent activities in fraud detection, and enhancing user experience through recommendation systems.
  • Support, confidence, and lift are crucial metrics for evaluating the effectiveness of association rules, providing insights into the frequency, reliability, and dependency of identified relationships.
  • Explore three key algorithms—Apriori, Eclat, and F-P Growth—that drive the generation of association rules, each offering unique advantages in terms of execution speed, data scanning efficiency, and scope of application.

Frequently Asked Questions

Q1. What are the disadvantages of association rule mining?

A. The drawbacks are many rules, lengthy procedures, low performance, and the inclusion of many parameters in association rule mining.

Q2. Are there types of association rules?

A. Yes, there are four types of association rules in mining. These are multi-relational, quantitative, generalized, and interval information association rules.

Q3. Enlist some tools important for association rule mining.

A. The tools of significance in the association rule are RapidMiner, WEKA, and Orange.

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