Wednesday, 8 October 2014

Week 3, 4, and 5

A lot has happened in the past few weeks. Three lectures, two tutorials, an assignment, and a midterm. I managed to survive it all and came out (I hope) relatively unscathed. Week three was a good lecture, conjunction, disjunction, a couple of Venn Diagrams, negations, truth tables, and laws. There was one area of confusion during the lecture that I had an opportunity to ask Professor Zhang about. It was that the conjunction x>20 and x<10 is represented by AUB (A being the first term, and B being the other) but it could not be used to represent a disjunction since the intersection could not exist. I was thinking about the conjunction as a Venn Diagram where both circles were shaded in except for the middle, when I asked it was cleared up that it cannot be represented by a Venn Diagram since there is absolutely no possibility of intersection in that statement. The rest I was confident about as it was discussed. There is, however, quite a big difference between seeing someone doing something and understanding it, then having to do it yourself. I can easily say that I struggled with the tutorial that week, only solving about 3 problems from question 1, then being confused as to how people had any idea how to solve the rest. I didn't leave any more informed on how to solve a problem than when I came in. Seems like a good time to start working on the assignment, right? Wrong, very wrong, I don’t think I have ever really experienced that level of confusion before. I poured countless hours into trying to figure it out the weekend after lecture 3, I wish I had just waited for lecture 4, as a lot of it was explained then.


Starting off a lecture with informing the class that the midterm was next week probably wasn’t the best way to go about things. I knew it was soon, but hadn't realized it was so soon, and seeing as I was in a state of mass confusion from the assignment, it was terrifying. Although the proofs were not of too much help, the bit on the bi-implications, transitivity, and mixed quantifiers were. This lecture, along with going to the help center (which really wasn't of too much help), and pouring more countless hours into the assignment allowed me to finish it with some confidence about the answers, and only one question left blank. In the end, question 1, 2, and 5 were good, 3, and 4 were where I was unsure of myself, 4b was the question I left blank. I had no idea why the Venn Diagrams would be different between 4a and 4b (universal versus existential Venn Diagram). My next area of focus was the approaching midterm. I took to the internet and found a bunch of past tests that I attempted to do, as well as the sample test provided on the course website. I knew I wanted to see Professor Zhang in person regarding what I struggled with on the assignment and past tests, so I made quite an effort (changing work schedule, putting off my weekly cooking) to come in and clear the confusion up. I am so glad I did because now I actually feel I understand the course. The midterm went very well I feel. The questions were extremely similar to the sample midterm, I would even venture to say they were easier version of them, and one similar to 4 on the assignment, which I cleared up during the office hour. Then there was lecture, and a whole lot of proofs. I believe I will need practice with those, but it looks like the general formula is work both ways (from the top, and from the bottom), try proving the contrapositive if it’s easier, and seeing if its contradiction makes sense. I’ll just have to do some myself to see if I would be able to without help, that’s what the tutorial is for.

Friday, 19 September 2014

First Two Weeks

The first lecture of CSC165 introduced some concepts to me that I had not seen before. Luckily, Professor Zhang kept it light by having several funny memes to reiterate his points. I saw some Python code for the first time and that was confusing for me because I hadn’t had my first CSC108 lecture yet. It’s too bad the code wasn’t in Java seeing as I already know that computer language. Soon enough it became clear what was happening and I was following along better, not easily as the concepts were still new, but better. The problem solving approach by George Polya was shown to us and it seemed very reasonable. I think most people follow that method without realizing it since diving into a problem without any plan is likely to lead nowhere. I found the streetcar problem interesting, I thought I had all the facts right but they weren’t adding up to a solution. In the end I was thinking too much like a human, I hadn’t realized that when Person B says, “that still doesn’t really tell me how old they are” that they were actually able to do the calculations and conclude that the previous information of the product of the kid’s ages and the sum does not give one solution. I enjoyed working on that with the class as it was a team effort to solve. Next we were taught about universal and existential quantifiers, this part seemed very straightforward as it is easy to tell when a sentence describes all of a set or only some of it. I left the lecture fairly confident in what had been discussed, I wish I could say the same about the second lecture, but that one was quite different.

The second lecture started off strong, with confusion that is. The “before today you talk like” and “after today you talk like” really set that up. The Venn Diagrams were clear enough, but still made difficult to understand due to the expressions they represented being unfamiliar to me. The symbols from chapter 1.5 were then used to replace the expressions I was already having trouble understanding. As we went over it more, I began to comprehend what was happening. I felt like I could follow, but would probably be unable to do any on my own. The next set of Python functions used to describe quantifier claims were simple for me to understand, the use of the word “all” and “any” in the functions had a lot to do with its simplicity. Before this class I did not know there was a difference between a sentence and a statement, it was explained well and I was able to grasp the concept. The same goes for the predicates that we learned. At first the implications made sense in the form of an if…then… statement. Then the sentences without the general format came and that was really quite different for me as I am in no way good at language courses, high school english was usually my worst course. It made sense once the answer was on the screen, but before that I usually couldn’t tell which one was P and Q. The idioms and “weird” equivalence statements were easy to follow. The class concluded with the “before” and “after” segment it started with, which I still didn’t understand. Leaving the class I felt quite shaken and definitely unconfident in the course.


The tutorial questions seemed simple enough when doing them. Then I arrived at the tutorial only to find I had done the entire second question wrong. I hadn’t realized that the Venn Diagrams had to be filled enough just to prove the equation and I filled it how the question would appear to be filled when the statement is true/false. After correcting and understanding my mistake, the quiz was surprisingly simple to complete. Seeing as this is my only class that has material I have never seen before I would say it is my most difficult at the moment.