8.1

CptS 401

Adam Carter

Announcement

Executive decision: no class Thursday!

(CH 8.3-8.4 and exam review will take place tomorrow instead)

Be sure that you submit a digital copy of your final submissions!Failure to do so may result in a reduced

grade

Quiz Question

The cause of computer system failures can be attributed to

A. Faulty design

B. Slow computers

C. A & B

D. None of the above

3

Answer

A “…faulty design, sloppy implementation, careless or insufficiently trained users, and poor interfaces” (405)

4

Quiz Question

The following is not a factor that contributes to the problems that computer databases cause for people:

A. A large population

B. Automated processing without human intervention

C. Inaccurate biometric data

D. Errors in data entry

E. Lack of accountability for errors

5

Answer: CSeveral Factors Contribute to Database Problems

A large population (many with similar names)

Automated processing can’t always recognize special cases or doesn’t use common sense

Overconfidence in accuracy of data Human errors in data entry Data are not updated or maintained Humans aren’t accountable for problems

(blame it on computer!)

6

Quiz Question

In the context of Ch. 8, RSI stands for

A. Redundant System Inputs

B. Recalibrated System Integrity

C. Repetitive Safety Isometrics

D. Redundant Safety Information

E. None of the above

7

Answer: RSI = Repetitive Strain Injuries (E)(see gray box on p. 411)

Have you experienced pain from using a keyboard or mobile device for extended periods of time?

A: Yes

B: No

8

Quiz Question

A strategy mentioned by the book for making electronic voting machines less vulnerable to fraud and sabotage is

A. requiring the machines to be housed in a locked cabinet

B. requiring the software they use to be public

C. keeping the software they use secret

D. All of the above

E. None of the above

9

Answer

B (416)

Is having open-source software on voting machines a good idea?

10

Quiz Question

The book discusses the failures of complex computer systems at three different airports. What was a common reason all three failed?

A. They had not undergone sufficient testing

B. They were unable to handle incorrect user input

C. They were too complex to work properly

D. None of the above

11

Answer

A (419)

The book implies that all three systems were rushed.

Do any of our students from Hong Kong remember the airport incident there?

12

Quiz Question

In the past 10 years, the number of fatal accidents in relation to total flights

A. Has gone up

B. Has gone down

C. Has stayed the same

Answer

B (424)

Discussion

Has anyone in this class been the victim of computer error?

Class Discussion

Do software errors worry you?

Discussion

So far, the Daemon’s plans have executed perfectly. Given what we know about software failure, does this seem likely?

Discussion

The book provides several examples of people placing complete trust on computer results. Is this a positive (good) trend?

A. Yes

B. No

Discussion

The book mentions that at the time of the writing (2008), 30,000 people have been falsely identified as terrorists. More than likely, this number has gone up.

Given that there are probably significantly less than 30,000 terrorists in the world, do our precautions work?

Discussion

Y2K : Real or hype?