FAQ ON PATTERNS WEEK 2.

FAQ ON PATTERNS.

After today’s lecture, there was a lot of argument in class, so because of that the lecturer asks us to prepare some FAQ for new comer in pattern. The following are the question and answer.

1. Is there a better definition for pattern
For a new person that is just introduce to pattern, the best for the person is to give a simple definition for patterns that is pattern is solution to a problem in a context.
Problem refers to a set of forces goals and constraints that occur in this context.
Solution refers to a canonical design form or design rule that someone can apply to resolve these forces.

2. Is there a better word to describe pattern.
Pattern can be called anything you like.

3. What's the difference between class and pattern?
A pattern is not an implementation. It describes when, why, and how to go about creating an implementation or other engineering product.

4. Who is Christopher Alexander?
Alexander is an architect in the sense of buildings, not software who invented patterns.

5. Are there any disadvantages in pattern taking a negative form?
Perhaps ideally not sets of good patterns would steer you clear of the infinitely many bad designs sometimes called antipatterns you could come up with, as well as all of the contexts in which it is not appropriate to apply a given pattern. But some ideas are so bad yet so prevalent that they deserve explicit mention. One way to do so is to include a Common traps and pitfalls section in a pattern description. Descriptions of bad solutions can form part of the motivation, rationale or forces for a good solution. Patterns may also describe ways of transforming bad solutions into good ones.
5 Some people think pattern is just ideal that can be given to then by anybody.
Because some patterns are so good and useful that even your grandmother knows them. Writing them down makes the context, value and implications of the advice clearer than your anybody probably did.

6. Why should I use patterns?
For the same kinds of reasons that you should reuse good code: Benefiting from the knowledge and experience of other people who have put more effort into understanding contexts, forces, and solutions than you have done or want to do. Further, patterns can be more reusable than code, since they can be adapted so that you can build software to address particular special circumstances that cause you to be unable to reuse an existing component.

7. How do I go about writing a pattern?
This recommendation can be followed.
8. Avoid writing about patterns; just write patterns.
a. Aim for quality, not quantity of patterns.
b. Figure out why the pattern exists or applies.
c. Pick a format for writing about it.
d. Continually iterate and refine.


9. How many patterns do we have?
Some people think there are relatively few undiscovered patterns that nearly everyone ought to know about. Some people think that there are a great many more domain-specific patterns that need to be written.

10. Is the use of patterns necessarily iterative?
In principle, you could be very lucky and have a problem for which there is already a complete set of patterns, and in which each application of a pattern flows into the next, leading to a final product without ever backtracking. But people are never this lucky.

11. Wouldn't it be more useful to teach people to write patterns rather than teaching them to use a bunch of existing patterns?
Both are needed. Neither is more needed.

12. How can we institutionalize the use of patterns where I work?
This recommendation can be followed.
a. Extend design documentation and review practices to also deal with design patterns.
b. Run courses on the use of existing design patterns.
c. Review existing patterns in a writer's workshop.
d. Use a pattern-based style template for documenting designs.

13. Can you use patterns in very large development efforts?
I think yes, because a lot of people has do so and its works for them.

14. Do patterns really work?
Yes it does.

NB
Some people incorrectly use the term design pattern to refer to any object structure, even if it is not in any sense a pattern. Please don't do this.


REFERENCE.
http://g.oswego.edu/dl/pd-FAQ/pd-FAQ.html

PATTERNS WEEK 1.

PATTERN

“According to Alexander’s definition of pattern, he describes pattern as a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice.”

After digesting of this definition and the reading of the note give about pattern, I define pattern in my own way, pattern is method by which different or similar problem occur all the time and you find a permanent way of solving that problem in case the problem occur again and there are different context involved in solving different problem.

After this lecture about pattern, I got to know that pattern is a real life thing that happens every day to solving human being problem in all aspect of life. Pattern is everyday thing because all the invention in the world today is done because of the problem people are facing everyday.
After the digestion of pattern and its relations, i decided to create a new real life pattern for my reading.




PATTERN IN REAL LIFE.

You are a student, you work full time and you school full time, and you want to get a 1st class result in your university degree BSC.
Your lecturer want you to come to class as early as possible, and also your manager at work want you to come to work early to avoid been send off at work but he offer you a solution of, if you know that u can come to work early then change to a part time job but if you change to a part time job, you need money to pay your school fine because you are already owning the school a lot of money.
Your brother wants to help you but he does not have money to give because they have not paid him at work. And there is nobody that is ready to borrow you money because they knows that u are a student.

PROBLEM: Want a 1st class result in the University for Bsc Degree.

SOLUTION: Stop working or work part time.

CONTEXT: You have to leave some of the thing you want to pay for so that you can get a 1st class result.