The Organization of UML - The Layered Metamodel
18 important questions on The Organization of UML - The Layered Metamodel
One way that it becomes possible to have a model of a modeling language is...?
We call a model of a modeling language a ...?
Therefore, all the MOF models used to provide the formal abstract syntax for UML are ..?
In philosophy and mathematics, this separation into levels is common to prevent malformed statements that can result in a paradox.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
What are the Levels / Layers of MetaModeling.
What is the M0 Layer?
- The implementation world
- Instances, database records, tables, executables are the elements here
- In a Library system, the books and the patrons in the Library database are level M0. Generally, there is one M0 object to represent the M-1 things
What can you do with it?
You can implement this layer
What is the M1 Layer?
- The modeling world
- Your model lives here and describes the things in the M0 layer
- Your model of the Library system is an M1 level description of the M0 implementation. The Book and Patron Classes live here
What can you do with it?
You can model in this layer
What is the M2 Layer?
- The metamodeling world
- The elements in this layer are the elements of UML. The M1 level uses the M2 elements. Models at this level give the abstract syntax, the grammar of UML MOF. The METACLASSES Class and Object lives here
What can you do with it?
You can read the specification in this layer
What is the M3 Layer?
- The meta-metamodeling world
- This layer describes the MOF elements. The MOF is used to write the grammar of UML and several other OMG languages. The meta-metaclasses MOF Class and MOF object live here
What can you do with it?
Not Much
When we talk to people about the metamodel, we are talking about a ... ?
If you were making a system for a Library, there could be at least three things called Books.
What are they?
1. The physical books (M-1)
2. The books in the implementation (in the app, database table, runtime objects) (M0)
3. The class Book in the model (M1)
We cannot put an implementation level element (MO) into the ...?
Not only are there too many book records in the Book table of the database, but essentially a model-level element is not an implementation element.
To distinguish the M0 objects from the M1 element version that represents them, we call the model versions, INSTANCE SPECIFICATIONS, though commonly we still call them OBJECTS
It is also possible to show some of the attributes of the class Book in the next compartment. You will find this useful because you can show the current values that the object has in these slots.
Why do we draw such objects (instances)?
These diagrams are often useful to show examples to fellow workers or to help set up a test.
We can emphasize the relationship between the instance of a book and the Book class, by connecting them on a diagram.
What is the notation for this?
- We use a dashed arrow pointing from the instance to the class.
- This arrow indicates a nonspecific DEPENDENCY.
- In this case, the object or instance DEPENDS on the class definition.
We can also represent in our models some M2 level elements.
In fact, all the abstract syntax diagrams are metamodels of that level.
Like a class, a metaclass is also ...?
How do we mix diagrams?
We place the terms «Metaclass» or «Class» above the names as shown in Fig. 4.6.
![]()
Why do we indicate that this is a Metaclass?
In the abstract syntax diagrams within the UML specification, the «Metaclass» stereotype is omitted
As an example of the abstract syntax of UML, we show, in Fig. 4.7, a partial definition of a UML Class.
In this metamodel, we indicate that a ....?![]()
In UML, the notation is not always sufficiently precise to determine the part of UML (element type) that is being modeled.
Therefore.... What can you use to clarify this?
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
