CS 3001 Midterm || with Complete Solutions.
What happened with the Therac-25? correct answers There was a malfunction with the software
due to many casual factors which led to multiple accidents which also led to 3 deaths between
1985-1987. There were 11 installed machines and 6 accidents. FDA did not have any formalized
procedures at the time and the company creating the machines, AECL, were Canadian. For every
accident, there are an estimated 600 close calls/minor incidents. Low reporting bc of peer
pressure, fear of regulatory bodies, and fear of lawsuits.
What are the differences between the Therac-20 and 25? correct answers 20 had built in
hardware checks which contained the possibility of overdosing but the 25 relied solely on
software which was integrated with the machine and led to overdoses.
What was the cooperate response to the Therac-25? correct answers AECL repeatedly said "that's
not possible" when told of errors. Falsely said they increased safety by 5 orders of magnitude. A
better response would include warning users, and recreating the error to understand the problem.
When radian machines are taken out the market, life changing treatment is not as accessible.
What are the casual factors for the therac-25? (10 things) correct answers 1. Overconfidence in
software
2. Confusing reliability with safety
3. Lack of Defensive Design
4. Failure to eliminate root causes
5. Unrealistic risk assessments
6. Inadequate investigation or follow-up on accident reports
7. Inadequate software engineering practices
8. Software reuse
9. Safe versus friendly user interfaces
10. User and government oversight and standards
Examples of artifacts with intentional politics? correct answers Bridges in NYC are built
intended to keep poor people away from beaches because public buses are not able to go there.
We know it was intentional bc the designer was racist and said racist things.
Example of artifacts with unintentional politics? correct answers Stairs were not intended to
exclude people in wheelchairs. Another example is the tomato harvester. It saves money but
gives advantage to big farms and tougher tomatoes are made.
Example of something that is not wrong, but harmful. Example of something is is wrong, not
harmful correct answers For first, taking a job that someone else needed it more.
For second, white hat hacking: hacking into OS to tell developers about an error.
Relativism
Cultural relativism correct answers You are a passenger and your friend speeds and get into an
accident. Depending on what culture the people were, they would rat them out. Saying it is
relative does not explain anything due to cultural differences.
, Explain both types of Utilitarianism correct answers Act U: Performs analysis on each act and
how much utility/happiness it generates for affected parties.
Problems:
-does not account for innate sense of duty. It says breaking promise is okay if it generates for
happiness.
-morality has nothing to with intent.
-no absolute right. i.e. okay killing someone to give 10 ppl organs.
Rule U: Adopt moral rules, if followed by everyone, will lead to most utility/happiness.
Advantages over Act U:
-calc is easier.
-would argue keeping promise benefits everyone if followed by everyone.
-solves problem of bias. "is it okay for EVERYONE to do it?"
-solves problem of moral luck
Deontology/Kantianism correct answers Based upon rationalist view that the rightness or
wrongness of an act depends upon the nature of the act, rather than consequences.
What are the categorical imperatives? correct answers First formulation:
"Act only from moral rules that you can at the same time will to be universal moral laws."
Ex. you can break a promise
-illogical as it contradicts the whole point of making a promise.
Second formulation:
"Act so you always reat yourself and other people as ends in themselves, and never only as a
means to an end."
Ex. you want to hire new works for plant but plan to move out of state later.
-You have to tell them or you would be using them (intention behind an action is primary).
Advantages and disadvantages of categorical imperatives correct answers Advantages:
-rational, universal, and applies to everyone.
-all people are treated equal.
Disadvantages:
-no single rule characterizes an action.
-ex. stealing food to feed starving children.
-allows no exceptions like social lies.
Perfect vs Imperfect duties correct answers Perfect Duties: follow all the time
Imperfect Duties: follow when can
Ex. Perfect duty "do not steal" takes priority over imperfect duty "help less fortunate"
Ex. you need to lie to save someone's life.
Kant says being truthful is perfect duty and there are no exceptions.
What happened with the Therac-25? correct answers There was a malfunction with the software
due to many casual factors which led to multiple accidents which also led to 3 deaths between
1985-1987. There were 11 installed machines and 6 accidents. FDA did not have any formalized
procedures at the time and the company creating the machines, AECL, were Canadian. For every
accident, there are an estimated 600 close calls/minor incidents. Low reporting bc of peer
pressure, fear of regulatory bodies, and fear of lawsuits.
What are the differences between the Therac-20 and 25? correct answers 20 had built in
hardware checks which contained the possibility of overdosing but the 25 relied solely on
software which was integrated with the machine and led to overdoses.
What was the cooperate response to the Therac-25? correct answers AECL repeatedly said "that's
not possible" when told of errors. Falsely said they increased safety by 5 orders of magnitude. A
better response would include warning users, and recreating the error to understand the problem.
When radian machines are taken out the market, life changing treatment is not as accessible.
What are the casual factors for the therac-25? (10 things) correct answers 1. Overconfidence in
software
2. Confusing reliability with safety
3. Lack of Defensive Design
4. Failure to eliminate root causes
5. Unrealistic risk assessments
6. Inadequate investigation or follow-up on accident reports
7. Inadequate software engineering practices
8. Software reuse
9. Safe versus friendly user interfaces
10. User and government oversight and standards
Examples of artifacts with intentional politics? correct answers Bridges in NYC are built
intended to keep poor people away from beaches because public buses are not able to go there.
We know it was intentional bc the designer was racist and said racist things.
Example of artifacts with unintentional politics? correct answers Stairs were not intended to
exclude people in wheelchairs. Another example is the tomato harvester. It saves money but
gives advantage to big farms and tougher tomatoes are made.
Example of something that is not wrong, but harmful. Example of something is is wrong, not
harmful correct answers For first, taking a job that someone else needed it more.
For second, white hat hacking: hacking into OS to tell developers about an error.
Relativism
Cultural relativism correct answers You are a passenger and your friend speeds and get into an
accident. Depending on what culture the people were, they would rat them out. Saying it is
relative does not explain anything due to cultural differences.
, Explain both types of Utilitarianism correct answers Act U: Performs analysis on each act and
how much utility/happiness it generates for affected parties.
Problems:
-does not account for innate sense of duty. It says breaking promise is okay if it generates for
happiness.
-morality has nothing to with intent.
-no absolute right. i.e. okay killing someone to give 10 ppl organs.
Rule U: Adopt moral rules, if followed by everyone, will lead to most utility/happiness.
Advantages over Act U:
-calc is easier.
-would argue keeping promise benefits everyone if followed by everyone.
-solves problem of bias. "is it okay for EVERYONE to do it?"
-solves problem of moral luck
Deontology/Kantianism correct answers Based upon rationalist view that the rightness or
wrongness of an act depends upon the nature of the act, rather than consequences.
What are the categorical imperatives? correct answers First formulation:
"Act only from moral rules that you can at the same time will to be universal moral laws."
Ex. you can break a promise
-illogical as it contradicts the whole point of making a promise.
Second formulation:
"Act so you always reat yourself and other people as ends in themselves, and never only as a
means to an end."
Ex. you want to hire new works for plant but plan to move out of state later.
-You have to tell them or you would be using them (intention behind an action is primary).
Advantages and disadvantages of categorical imperatives correct answers Advantages:
-rational, universal, and applies to everyone.
-all people are treated equal.
Disadvantages:
-no single rule characterizes an action.
-ex. stealing food to feed starving children.
-allows no exceptions like social lies.
Perfect vs Imperfect duties correct answers Perfect Duties: follow all the time
Imperfect Duties: follow when can
Ex. Perfect duty "do not steal" takes priority over imperfect duty "help less fortunate"
Ex. you need to lie to save someone's life.
Kant says being truthful is perfect duty and there are no exceptions.
