Java Problem Taxonomy

ACM Java Task Force Taxonomy of Problems in Teaching Java
— DRAFT (February 27, 2004) — The ACM Java Task Force is charged with developing a stable collection of pedagogical resources that will make it easier to teach Java to first-year computing students. To do so, one of the first tasks the task force must engage is to identify the problems that currently make Java teaching difficult.Fortunately for the task force, much of that work has already been done, in the sense that many papers in the literature of computer science education have already described a variety of problems and concerns. This paper represents the result of a literature survey intended to identify and classify the problems that have generated the greatest level of concern. We have divided the issues raised about Javaas an instructional language into three categories: high-level issues that are in some sense beyond the details of the language itself, language issues that arise from the design of Java itself, and API issues associated with the application programmer interfaces provided as part of Sun’s standard Java releases. The issues in each of these categories are shown in the following list along with acapsule assessment of their current status as problems for the community: High-level issues: H1. Scale H2. Instability H3. Speed of execution H4. Lack of good textbooks and environments Language issues: L1. Static methods (including main) L2. Exceptions L3. Poor separation of interface and implementation L4. Wrapper classes L5. Lack of parameterized classes (templates) L6. Lack of enumerated typesL7. Inability to code preconditions L8. Lack of an iterator syntax L9. Low-level concerns API issues: A1. Conceptual difficulty of the graphics model A2. GUI components inappropriate for beginners A3. Inadequate support for event-driven code A4. Lack of a simple input mechanism (remains a concern) (remains a concern) (improving over time) (improving over time) (remains a concern) (remains aconcern) (partly addressed by tools) (fixed in Java 1.5) (fixed in Java 1.5) (fixed in Java 1.5) (fixed in Java 1.4) (fixed in Java 1.5) (disposition varies) (remains a concern) (remains a concern) (remains a concern) (largely fixed in Java 1.5)

As the annotations in the right-hand column indicate, many of the problems with Java reported in the literature have been solved, either by incrementalimprovements over time or by new releases of the Java environment. Java Standard Edition 1.4 [Zukowski02], for example, added an assertion mechanism to Java, thereby enabling the specification of preconditions. The many changes—parameterized types, enumeration types, boxing and unboxing of primitive data, an extension to the for statement syntax to support iteration, and new APIs to support concurrencyand formatted I/O—introduced in Java 1.5 [Austin04, Heiss03] will have an even more dramatic effect on pedagogy.

ACM Java Task Force: Taxonomy of Problems in Teaching Java

–2–

While the release of Java 1.5 is likely to solve several problems, its adoption in the near term represents a significant challenge to the educational community. Java 1.5 has not yet been officially released, andit is not clear how quickly educational institutions will be able to adopt it. Moreover, given that we have no experience teaching using the new language features included in Java 1.5, there is no direct evidence to indicate how well the new facilities will work in the classroom. In light of this uncertainty, the Java Task Force has decided that its recommendations must be implementable, at leastin part, by those who continue to use environments based on Java 1.2. The rest of this paper offers further details on the set of problems we have identified from the literature, organized according to the taxonomy described earlier in this report.

High-level issues
This section outlines those challenges that in some sense transcend the details of the Java language and its libraries. These...