Mid-Term Exam Grades

I gave exams back on Tuesday, November 2. Here is now I calculated the final score.

I took all of the raw scores, which were out of 181 points, and averaged them. The average was 116, which was about 64%.

From that average I found the standard deviation to be about 33. For more on this means, read the wikipedia article.

Now I "binned" all of the students' grades. If a student was within one-half the standard deviation either above or below the mean, that person was put in the "B" bin. If the student was above a half-standard-deviation above the average, that student was put in the "A" bin. Maybe this will be clearer as a list.

Standard deviation is s. The student grade is g. The average is v.

• g > v + s --- A+ ---- 98-100


• v + s/2 < g < v + s --- A --- 90-97


• v - s/2 < g < v + s/2 --- B --- 80-89


• v - s < g < v - s/2 --- C --- 70-79


• v - 2s < g < v - s --- D --- 60-69
• g < v - 2s --- below -- 50-59

Within each bin the grades were scaled to fit the final score range of that bin. For example, all the grades in the "B" bin ranged from 104 to 129. That is a range of 25 points. I re-mapped that range to the range of "B" class final scores, which is 80-89, with this simple formula:

(g-104)/24)*9)+80

I repeated this with all the bins, and that is how you got your grade. The final distribution was:

• 7 A+
• 11 A
• 24 B
• 6 C
• 2 D
• 5 below

Any questions, come see me. If you think you've been mis-graded, come see me. I know of one question where I misinterpreted some student's answers. If you think you got it right but scored abysmally on one section, it might be you.

Viruses & Malware

Continued the Dark Side slides through cookies.

Talked about the different types of malware. Viruses can be classified by how they gain access to a system, and what they do once they're in.

Ways to get in:

• Trojan horse
• worm
• root kit

What they actually do (not a complete list):

• wabbit (massive self-cloning to clog system)
• Adware
• Spyware
• Zombie - Botnet

Just realized I did NOT talk about zombies and botnets in the 202 class.

Starting Security

All technology, including the internet, was designed and built by people for the use of people. This idea should always be remembered when dealing with internet security.

What is security? Protecting things of value. What has value? Anything we give value to. Recall the WoW kid and his non-understanding parent.

We did the "Dark side of the internet" slides up to Tiger Woods.

All nefarious acts on the internet have two categories: technical and social.

Recall the graph of "how to contact the person:" there were three branches: legit, tech hacking, and social engineering.

Technical (or straight hacking) defeats systems to obtain information or carry out the ill-intended deed. Social engineering is executing a con: tricking someone into giving something up. All false internet activity falls somewhere in the space defined by those two.

Topics for Mid-Term

definitions of terms

client/server model

server-/client-side processing

DNS

Server/Local copies

history of the internet

IP addresses

Binary

Size of data

HTML

CSS

hex colors

web browsers

Thursday October 14th:

Went over the turnin procedure for the website. We then had a nice revisit of binary number representation, converting between binary and decimal.

Tuesday October 12: No Class for Columbus Day

Thursday October 7th:

Worked on websites, I believe.

BIg Website Project

September 30 we introduced the big website project. The requirements are here: http://91-113-f10-ms.wiki.uml.edu/WebsiteProject

October 5 we worked on the project in-class, with the goals of

• 2 pages, linked together
• CSS file created and set up

Week 4: Mechanics and Downloads

We've done IP addresses, in that we know they identify computers on a network. We've looked at DNS, the domain name service that connects the name (uml.edu) to a number (129.63.1.11). This week, we asked the question "why do IP address numbers go 0 to 255?" The answer required learning about binary numbers.

Binary is the two-state representation of numbers inside a computer. For more references on binary numbers, look online. Try http://www.mathsisfun.com/binary-digits.html or http://www.wikihow.com/Convert-from-Decimal-to-Binary

We can now convert a base-10 decimal number into and out of base-2 binary representation.

This week we also learned about WinSCP, a program that lets us transfer files between the web server and our local machine. New concepts were introduced:

• local vs. server copy
• images

With WinSCP and a text editor (like jEdit or notepad++), we can edit our webpages locally on our computers, then upload them to server or all to see when we're ready.

September 14th & 16th

Website with superflous markup assignment was moved to be due September 15th, as the CS servers were having a problem with new accounts. Now everything is fixed.

We watched the History of the Internet video and took a short quiz on it.

Week 2 Summary

Tuesday, September 7

Talked about server-side processing (PHP) and client-side scripting (javascript). The base-level web interaction involves only straight text and pictures. Fancier features (like those folding/expanding titles) involve something active in the browser to change the page, and that's what scripts do. Sometimes the designer wants to give the browser custom information on each page load, and the server can do things and show the results to the browser. This is the basic jist of the class. If this isn't clear as day, ask for clarification.

Thursday, September 9

We finally got everyone logged into the CS department linux servers using puTTY on the lab machines. Using the nano text editor in the terminal, we started our first web page using the most basic tags. If you need help with putty, linux, or html, I have all the how-to's and tutorials here on the course page.

Assignment 1 is due Tuesday, September 14th at the beginning of class.

First Class 9/2/2010

Accomplished basic administrava. Section 201 did not get CS account forms, which I will have for them on Tuesday. Section 202 did get the forms, and their accounts are all set up and ready to be given out on Tuesday.

Both sections completed the pre-knowledge survey, and the results fell on a very wide interval, as expected. Nobody knew everything, which means that everybody has something to learn from the class.

My biggest concern is checking of email. Students in this class must check email often, at about once per day, to be successful. If it is not part of the daily habit, it needs to become part of it, because it is simply necessary for success in this class as well as for improved Internet-life skills.

I pose a question to my students: how often do you check other sites? How often do you check facebook or myspace? Please email me with "91.113" in the subject and tell me a) how often you reported to check your email on the survey b) how often you check facebook, or whatever else it is you use online. If there is some other site you use or read everyday (or often) tell me that.

Topics covered in class included the client-server model of information exchange. We used the peer-to-peer model to compare/contrast. We also went over the process of DNS lookup the web browser goes through to fetch a website. Both sections saw a live demo of nslookup, but only 202 got to see the IP put directly in the browser.

Next week: history.