Introduction to the Cognitive Load Project
The Cognitive Load project is an ongoing effort aimed at addressing a fundamental issue in software development: the confusion developers experience when interacting with code. This confusion is primarily due to high cognitive load, which is a real human limitation rather than an abstract concept. The project highlights that while much of a developer's time is spent understanding rather than writing code, it's crucial to ensure that the code does not unnecessarily increase cognitive load.
Understanding Cognitive Load
Cognitive load refers to the mental effort required by a developer to complete a task. It involves juggling various pieces of information like variable values, control flow, and call sequences. Since the human brain has a limited capacity, typically holding about four chunks of information, exceeding this limit can make comprehension challenging.
Types of Cognitive Load
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Intrinsic Cognitive Load: This is unavoidable and stems from the inherent complexity of the task itself. As software development can be naturally complex, this type of load can't be reduced.
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Extraneous Cognitive Load: This is influenced by how information is presented. Often caused by unnecessary complexities in the code, such as overly clever structures or obscure libraries, this load can and should be reduced.
The project emphasizes reducing extraneous cognitive load through practical examples.
Examples and Solutions
Complex Conditionals
Complex conditionals can overload a developer's working memory. To simplify, breaking down conditions into meaningful intermediate variables can help.
Nested Conditions
Instead of using nested conditions that increase cognitive load, adopting early returns can help streamline the logic, focusing on the main path of execution.
Inheritance in Object-Oriented Programming
Excessive reliance on inheritance can result in a burdening stack of logic that is hard to comprehend and maintain. The project suggests favoring composition over inheritance to manage this complexity.
Module Depth
Too many shallow methods or modules can lead to high cognitive load as a developer must understand all interactions. The project notes that deep modules with simple interfaces provide powerful functionality without overwhelming complexity.
Avoiding Shallow Microservices
While microservices can be useful, having too many shallow ones can cause integration challenges and increased complexity. The project suggests a balanced approach, opting for more consolidated "macroservices."
Overuse of Language Features
While programming languages evolve, an abundance of features can make the language difficult to navigate. Limiting the number of features used can ease cognitive strain.
Simplifying Business Logic
Instead of encoding business logic into numeric HTTP status codes, plain, self-descriptive strings are recommended, reducing the mental effort required to understand the codebase.
Rethinking the DRY Principle
The "Don't Repeat Yourself" principle, when over-applied, can lead to tightly coupled systems that are hard to maintain. A recommended practice is to allow some level of code duplication to avoid unnecessary dependencies.
Framework Dependencies
Frameworks should be used in a library fashion rather than embedding business logic within them. This keeps the core logic adaptable and lessens the learning curve for new developers.
Architectural Considerations
Layered architectures, while intended to separate concerns, can increase complexity. The project advises against unnecessary architectural layering unless there is a clear, practical benefit.
Clarifying DDD Misconceptions
Domain-Driven Design (DDD) is valuable but is often misunderstood. It focuses on the problem domain rather than specific implementation patterns. The project emphasizes maintaining a clear understanding to ensure alignment with the true spirit of DDD.
In summary, the Cognitive Load project offers insights and strategies for reducing unnecessary complexity in software development, aiming to improve code readability and maintainability while respecting the natural limits of human cognition.