Students' Difficulties in Identifying the Use of Ternary Relationships in Data Modeling

Introduction

The research literature includes an academic discussion on the difficulties novice modelers may encounter when designing a data model addressing given requirements in general (Dey et al., 1999) and regarding ternary relationships in particular (Hitchman, 2003; Batra, 2007). They encounter many difficulties, mostly concerned with cognitive complexity; among them, No Flexibility for errors, lack of immediate feedback, and information overload (Batra, 2007). As a result, data models designed by novice modelers tend to be inaccurate and erroneous, and hence the cause for the faulty behavior of information systems.

During their studies, novice data modelers study how to design a data model addressing given requirements. They study how to identify entities and how to set relationships between them. They also learn how to transform the entities and relationships into tables, fields and keys in order to form a relational schema.

One of the main challenges novice modelers face during the design phase is the identification of relationships between the entities involved. Novice data modelers find the setting of relationships between entities as their main challenge, mostly when non-binary relationships are involved (Batra, 1994).

However, existing research is mainly focused on theoretical rather than empirical aspects of data modeling. That is, there has been little exploration of empirical data gathered from novice data modelers. Such empirical findings might shed light on the causes of the difficulties novice data modelers encounter during the design phase, and help instructors to improve their practice.

The aim of this study is to explore the difficulties novice data modelers encounter as novice data modelers regarding relationships between three entities. For this purpose, students who had completed a database course were asked to fill out a questionnaire including two problems dealing with various requirements, necessitating that their solutions use both binary and ternary relationships.

The research questions derived with the above aim are:

• 1.

  What are the types of error relating to the use of ternary relationships?

• 2.

  What are the underlying reasons for these errors?

Theoretical Background

In this section, we present a brief theoretical survey of data modeling complexity, ternary relationships and students' difficulties in data modeling.