Month Year Issue

September 2004 Issue: 33

Journal of Conceptual Modeling
www.inconcept.com/jcm

Editor's Corner
by Patrick Hallock

I just see it differently
Just yesterday I was speaking to a group of object-oriented professionals. To keep the record straint, I do like these people and there programming styles etc. However, most of time we butt heads over - what is an object? One method is the object-attribute approach. Using this approach one finds and objects and then assigned attributes to the object. For example, "Car is provided in Color". The object is “car” and color is an attribute of the car. Isn’t color an object on it’s own? I think of color as an object that has a relationship with car. Once the rules for this relationship are known then we know how to handle the relationship. In one case, I could use a rule that limits the car to one color - Rule: Car is at most one Color". I could alternatively use a rule that says the car can be of several colors - Rule: "Car can have many Colors". Then I could constrain that many color rule by saying no more than three colors. There is another interesting difference. If one jumps to the idea that a car is of the color “red” it is tempting to align color to the car as in putting an attributed into the box with car. In my case we are really aligning color with car, but not in the same box unless we can prove it belongs there. If the first rule – car has one color, then we can put the color into the box with car. If the car can be of many colors and that color can be for many cars, then the car has a set of colors. Usually in logical model diagrams this is done by having an object called color (table:Color(colorname)) and a (table:Car) and then (table:car,color). Suddenly color, which was not an object, has now becomes an object that plays the role of an attribute for a car. Object Role Modeling (ORM) always sees things as objects at the conceptual level. Once the rules of all relationships are determined; only then is a logical model derived. That logical model differs based on the rules. It may now appear as an attribute only, or it may appear as an object playing a role with car. In either case, being an attribute is a or an object is based on the rules of the relationship and most importantly it is based on traceable fact and rules. Everyone knows how the model the way it is. All tings are objects at the conceptual level and may remain as an object or may become an attribute in the logical model. The point is, this is based on the relationship rules making a derived resolution between conceptual and logical models. This is postponing the decision until all the facts and rules are in place and then the logical model cartoon can be properly determined. Don’t worry I call all model diagrams cartoons even the ORM models. So why go into all this? Because!

The less Serious Section

Lessons Learned

I have been using a computer at home now for about 20+ years. The first one was an early model of the Apple. After buying many computers, I finally decided to make my own. Then I decided to start using laptops and I was back to buying. Now everyone who knows me well, also know that I am always adding trial software, buying software and trying things out. Or I just plain destroy the settings with an experiment. My computer is always loaded with collections of software based on “it sounded like a good idea at the time”. I have put the machines through the mill. I have messed-up my environment so bad that I had to just wipe the disk clean and start all over again. But never in all those years did I lose the disk itself. Well, now I have. A disk just decided to ruin my day, week, ah let’s say a month. The disk went to one of those places that recover data from ill-behaved disks. That took over a week. They recovered only some of the contents. I then had to install all the software over again. It was not because the software was not there; it was because the registry was one of those areas they could not recover. So I had a backup right? Sure and I have a bridge for sale over the Mississippi river. Now I have one of those USB external disks where you just push a button and it makes a backup -.the lazy man’s version. If my span between failures was assured to be another 20 years I would be 81 years old and probably would not even know what a disk is, assuming they still have disks then. But for now, I have learned an interesting lesson.

I hate the Mouse
It is a good thing that I am left-handed as left—handed people can usually use their right hand almost as well. Also Left-handed people are in their “right minds” (just had to say that). After using the mouse for a few years now I am all worn-out, both hands. Graphical interfaces with their mouse-driven interfaces are becoming very tiring. I am ready for those much promised new interfaces such as voice or hand movements in the air or even those that see that I am starring at something on the screen and goes there for me. Mice are something my cats should keep out of my house. Now I want to keep these mice off my desk as well. (Just between you and me – the keyboard as well.)

Just for Fun

Try visiting ThinkMap (www.ThinkMap.com). This is a "Visual Thesaurus” is new way to play with words. I used the word "Model". You navigate by clicking other words and then that word becomes the center of attetion.