Coincidental Cohesion (Worst - Very Low Cohesion)
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Introduction to Coincidental Cohesion
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Today, we'll explore coincidental cohesion. Can anyone tell me what cohesion means in software design?
Cohesion is how closely related the functionalities in a module are, right?
Exactly! Coincidental cohesion is the worst type of cohesion, where the functions within a module are grouped randomly. Think of it as a hodgepodge of unrelated tasks.
So, what's an example of that?
Great question! A module like `MiscellaneousFunctions()` that contains `PrintReport()`, `CalculateCRC()`, and `EncryptPassword()` exemplifies coincidental cohesion. They donβt relate to each other at all.
That sounds really confusing for anyone trying to maintain it.
Absolutely! Itβs like a 'dumping ground' for code. Let's remember: high cohesion is desirable; avoid coincidental cohesion by striving for functions that are closely related.
Consequences of Coincidental Cohesion
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Now, letβs delve into the consequences of coincidental cohesion. What challenges do you think it brings for developers?
It's probably hard to understand the code, right?
Correct! Besides being hard to understand, it leads to complications in testing. Since functions are unrelated, itβs difficult to define satisfactory test cases.
Does it also affect reusability?
Yes! Modules with coincidental cohesion are less likely to be reused because they donβt convey a clear purpose. Can anyone think of a real-world analogy for this?
It's like putting random tools in one toolbox. It takes longer to find what you need!
Exactly! Tools should be organized by type or function, just like software modules should be organized by related functionality.
Strategies to Avoid Coincidental Cohesion
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Letβs talk about ways to avoid coincidental cohesion. What strategies can we implement in our design?
We could break down large modules into smaller ones with specific tasks?
Exactly, Student_3! Striving for functional cohesion means each module should handle a single, well-defined task. What else?
We also need to ensure related functions are grouped together.
Right! Use descriptive names for your modules to reflect their purpose. This fosters clarity. Letβs remember: 'High cohesion, low coupling!'
So, keeping it focused helps with maintenance and testing too?
Absolutely! The easier we make our code to understand, the better it will be to maintain and test in the long run.
Introduction & Overview
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Quick Overview
Standard
This section discusses coincidental cohesion, the worst form of module cohesion where components are arbitrarily grouped together. Such low cohesion makes it difficult to understand, test, or maintain software, as functions lack interrelatedness and often become a 'dumping ground' for miscellaneous code.
Detailed
Coincidental Cohesion
Coincidental cohesion is characterized by a group of functions or operations that are bundled together in a software module without any logical relationship. This type of cohesion is the least desirable in software design, often leading to several adverse effects on the maintainability and quality of the software. When functions are included in a module purely by coincidence rather than by design, they become harder to understand, maintain, and test.
Key Characteristics
- Lack of Relationship: The functionalities within the module serve no common purpose. For instance, a module named
MiscellaneousFunctions()might comprise widely varying tasks likePrintReport(),CalculateCRC(), andEncryptPassword(), which do not interact. - High Unpredictability: Changes made to one function can unintentionally affect others in ways that developers cannot anticipate.
- Difficulty in Maintenance: As the module grows, the complexity increases, making debugging and enhancements troublesome.
Consequences of Coincidental Cohesion
- Difficult to Understand: Developers find it challenging to ascertain the purpose of the module.
- Poor Testing Outcomes: Testing becomes inefficient as unrelated functionalities may not have shared test conditions.
- Reduced Reusability: Because modules lack focus, they are less likely to be reused in other contexts, defeating one of the primary objectives in software design to create reusable components.
In summary, striving for higher forms of cohesion within modules, such as functional cohesion or at least sequential or communicational cohesion, is essential for ensuring strong, maintainable software architecture.
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Definition of Coincidental Cohesion
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Chapter Content
Definition:
The elements of the module are grouped together randomly, with no meaningful relationship between them. They are in the same module simply by coincidence.
Detailed Explanation
Coincidental cohesion occurs when a software module is made up of elements that have no relationship or logical connection. For instance, a module might include a collection of unrelated functions that were just bundled together due to convenience or apathy. This means that the functionality of the module lacks focus, making it hard to understand what the module is supposed to do.
Examples & Analogies
Think of a toolbox that contains a hammer, a paintbrush, and a pair of scissors. While all these tools might be found in a toolbox, they serve very different purposes and are not related to each other. Now, if someone asks what the toolbox is for, it would be confusing because thereβs no single focus.
Characteristics of Coincidental Cohesion
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Chapter Content
Characteristics:
The module performs completely unrelated functions. It's often a "dumping ground" for miscellaneous code.
Detailed Explanation
Modules with coincidental cohesion tend to lack organization and purpose. They contain various functions that do not logically fit together, making the module chaotic. This haphazard construction can lead to a situation where the module accumulates arbitrary pieces of code, which can be confusing for anyone trying to maintain or use the module. Thus, these modules are generally ineffective in accomplishing specific tasks.
Examples & Analogies
Imagine a kitchen drawer that contains a random assortment of items, like a spoon, a rubber band, a book, and a remote control. This drawer does not serve a specific function and is confusing to search through. Similarly, a module with coincidental cohesion presents challenges for developers who need to find or fix something specific within it.
Example of Coincidental Cohesion
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Chapter Content
Example:
A module MiscellaneousFunctions() that contains PrintReport(), CalculateCRC(), SortArray(), EncryptPassword().
Detailed Explanation
Taking the example of the module 'MiscellaneousFunctions()', this module could include functions that have no relationship whatsoever. For instance, it could have a function to print reports, another to calculate cyclic redundancy checks (a form of error-checking), and yet another to sort arrays. These functions serve different purposes and do not have a unifying theme. This randomness emphasizes the lack of unity and clarity in module design, which is problematic.
Examples & Analogies
Consider a junk drawer in your home that includes everything from batteries to old receipts to a broken toy. While all those items fit in the drawer, they do not belong together, making it difficult to locate anything you might need quickly. In the same way, the 'MiscellaneousFunctions()' module is cluttered, making it difficult for a programmer to locate or understand any specific function.
Consequences of Coincidental Cohesion
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Chapter Content
Consequences:
Extremely difficult to understand, test, reuse, or maintain. Any change in one part of the module is likely to affect others, and a minor change can have widespread, unpredictable side effects.
Detailed Explanation
The lack of focus in a module with coincidental cohesion leads to a host of problems. Since functions are unrelated, changes in one function may unintentionally impact other functions because they are all packed into one module. This interdependence increases the risk of bugs and makes the code harder to maintain. Consequently, such modules are challenging to test and reuse in other contexts.
Examples & Analogies
Imagine if your junk drawer contained items that were all connected somehow, like batteries that were meant for a remote control or a toy. If you removed the batteries to use them for the remote, youβd disrupt the toyβs function. Similarly, making changes in a problematic module can unintentionally break other functionalities within it, leading to unforeseen issues.
Key Concepts
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Coincidental Cohesion: The least desirable type of cohesion due to random grouping of module functions.
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Maintainability: The ability to modify software with minimal impact on unrelated parts.
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Reusability: The likelihood that software modules can be used again in different contexts.
Examples & Applications
A module MiscellaneousFunctions() that includes PrintReport(), SortArray(), and EncryptPassword() demonstrating random functionality without interrelation.
A system with a module handling both notification email and calculation of tax, which would typically belong to different modules under optimal cohesion.
Memory Aids
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Rhymes
Coincidental chaos, mix it up, functions scatter, like a pup.
Stories
Imagine a toolbox where hammers and spoons coexist awkwardly. This disorganization reflects coincidental cohesion!
Memory Tools
Get functional: Find, Focus, and Filter tasksβavoid Co-incident chaos!
Acronyms
C.A.R.E. - Coincidental And Random Elements signify bad design.
Flash Cards
Glossary
- Cohesion
A measure of how closely related and focused the responsibilities of a single module are.
- Coincidental Cohesion
A type of cohesion where elements are grouped randomly with no meaningful relationship.
- Maintaining Software
The process of making modifications to software to correct faults, improve performance or to adapt it to a changed environment.
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