This week we learned a bit more about drawing models and we reviewed event tables in the lecture.
We started off by analyzing the difference between OO and traditional approach. From what I understood, basically the focus of traditional approach is on the processes, whereas the focus of OO approach is on the objects of the system. I came across these two terms quite often during my course, but I never quite understood what OO meant and how it was any different..it makes a bit more sense to me now.
I've seen the 2 different formats of an Event table, and I think I prefer the SJB format over the Stumpf one. I think that's because last week we were introduced to the event table using the SJB format, so it is a bit more familiar to me and I understand it better.
I've been drawing DFDs ever since I was in high school. This part was nothing new to me, except maybe for the 'Realtime Link' symbol. I had never seen that one before. At first I thought that this was used whenever data is sent to and from an object/process, but then a few slides later I realised this was not the case. This symbol was only used when data had to be updated in real-time and sent back and forth. Of course, the name "Real-time link" should have ticked me off :)
Layers of abstraction was also familiar to me and my memory was quickly refreshed after Cheryl explanation. Quite an easy concept to understand; as you go into more details about the processes, you go into deeper layers. The context diagram is the highest level of abstraction as it has less details about the processes...it is the most 'abstract'.
DFd fragments were the small chunks of processes that had to be described in details. If within a fragment, there is another process that needs to be in more details, then another DFD fragment is created (subprocess).
DFDs have to be consistent.
Data cannot be created out of nowhere...
All data that flows out of a process must have flowed into that process or must have been generated by some data that flowed into that process.
...and data cannot just disappear
All data that flows in a process must flow out of the process or be used to generate data that will flow out of that process.
I thought the decision table/tree was pretty cool. It was a very simple way to show a decision making process..instead of using lots of "if" and "else". I have used the decision tree in high school before for Maths, but I thought the table was cleaner way to display the same information.
I must admit that by the time we reached IE models, I was phasing in and out of the lecture (9am lectures...sigh). I vaguely remember terms like CRUD matrix and I remember the dependency diagram. It should all come back to me when I do my reading tonite.
As for the tutorial, it was pretty cool. I enjoyed making the class-diagram although I'm not sure I got it all right. The event table was pretty straight forward as well. I think it shouldn't be that hard to create one for the assignment.
I've been listening to the assignment mp3 this morning and there were a few things that I had not picked up on during the interview. Now I'm not sure what we are supposed to do about them. I should've asked about them during the interview, but unfortunately listening to the recording only once was not enough.
