Test PrepTest Prep

CS 690CS 690

Test 1Test 1

How to Prepare – all topicsHow to Prepare – all topics

Make an outline for each subject/topicMake an outline for each subject/topicorormake flash cardsmake flash cards

For each major idea, write a short For each major idea, write a short paragraph summarizing the main pointsparagraph summarizing the main points

Be sure to know definitions of terms, so Be sure to know definitions of terms, so you can understand the questions.you can understand the questions.

How to Prepare - papersHow to Prepare - papers

Review any papers/systems Review any papers/systems What is its main overall purpose?What is its main overall purpose? How does it compare to similar How does it compare to similar

projects/systems/etc. ?projects/systems/etc. ?• e.g. SPIN v exokernel v microkernels (e.g., L4 )e.g. SPIN v exokernel v microkernels (e.g., L4 )

Pick out 3-5 major ideas/conceptsPick out 3-5 major ideas/concepts• Why did they do this research (motivation)?Why did they do this research (motivation)?• What is their “big idea”? How do they justify it?What is their “big idea”? How do they justify it?• Abstract, Introduction & Summary should be good Abstract, Introduction & Summary should be good

sources for much of the informationsources for much of the information

Other TipsOther Tips

Review your homework and read my Review your homework and read my comments.comments. If I said your answers were vague, focus on If I said your answers were vague, focus on

being more specific.being more specific. If I said “correct, but not necessary”, focus on If I said “correct, but not necessary”, focus on

answering the question that was asked, do answering the question that was asked, do not feel like you must give lots of background.not feel like you must give lots of background.

Read the question carefully and do what it Read the question carefully and do what it says!!says!!

Exam FormatExam Format

Multiple choice, matching or other Multiple choice, matching or other objective questionobjective question

Short answerShort answer ComparisonsComparisons ““What’s the significance of this concept”What’s the significance of this concept” State the main concept/purpose/reasonState the main concept/purpose/reason

Essay or paragraphsEssay or paragraphs

What Is a Good Answer?What Is a Good Answer?

The facts are right.The facts are right. It is not just something you have memorized and It is not just something you have memorized and

regurgitatedregurgitated It answers the question I asked, not the question It answers the question I asked, not the question

you thought I would ask.you thought I would ask. It addresses the main points and does not focus It addresses the main points and does not focus

on side issues.on side issues. It is not vacuous It is not vacuous It is organized and coherent, not just a collection It is organized and coherent, not just a collection

of key words strung togetherof key words strung together

How to Answer a Compare How to Answer a Compare QuestionQuestion

Question: “Compare/contrast an apple and an Question: “Compare/contrast an apple and an orange.”orange.”

Bad Answer: “An apple is red and crunchy while Bad Answer: “An apple is red and crunchy while an orange is juicy, and a member of the citrus an orange is juicy, and a member of the citrus genus.”genus.”

Better: “Apples and oranges are both fruits and Better: “Apples and oranges are both fruits and have a round shape. Apples are from the genus have a round shape. Apples are from the genus malus and oranges from the citrus genus. malus and oranges from the citrus genus. Apples are usually red, oranges are orange.”Apples are usually red, oranges are orange.”

In other words, look at the same attributes in In other words, look at the same attributes in both and decide how they are the same or both and decide how they are the same or different and if possible different and if possible whywhy..

Compare ExampleCompare Example

If you just describe and evaluate each If you just describe and evaluate each separately, you will not get full credit.separately, you will not get full credit.

Use phrases like “A does it this way; on Use phrases like “A does it this way; on the other hand, B does it that way”, or “A the other hand, B does it that way”, or “A and B both do this”.and B both do this”.

Significant Difference ExampleSignificant Difference Example

Similar to compare/contrast, but not Similar to compare/contrast, but not identicalidentical

Significant differences usually should be a Significant differences usually should be a difference in method or approach, not an difference in method or approach, not an effect of that method. So rather than say effect of that method. So rather than say “A is more efficient than B” give the “A is more efficient than B” give the difference in method or structure that difference in method or structure that causes A to be more efficient.causes A to be more efficient.

For ExampleFor Example Question: Give a significant difference between the FCFS Question: Give a significant difference between the FCFS

scheduling algorithm and RR scheduling.scheduling algorithm and RR scheduling. Good Answer: “FCFS removes a process from the run state Good Answer: “FCFS removes a process from the run state

when it blocks or terminates. RR removes a process from when it blocks or terminates. RR removes a process from the run state when it exceeds a pre-determined time-slice.” or the run state when it exceeds a pre-determined time-slice.” or “FCFS allows the process to decide how long it runs but RR “FCFS allows the process to decide how long it runs but RR has an upper limit to how long a process can run before has an upper limit to how long a process can run before another process is allowed to execute.”another process is allowed to execute.”

Not as good, but not terrible: “RR gives better service to short Not as good, but not terrible: “RR gives better service to short processes than FCFS”. Usually its better to concentrate on processes than FCFS”. Usually its better to concentrate on how things work and then address the effectshow things work and then address the effects

Bad : “RR uses time-slices, FCFS doesn’t”Bad : “RR uses time-slices, FCFS doesn’t” Notice: All of these answers compare on the same Notice: All of these answers compare on the same

characteristiccharacteristic

Vacuous AnswerVacuous Answer

A vacuous answer is one that doesn’t say A vacuous answer is one that doesn’t say anything useful, although it may sound anything useful, although it may sound authoritative.authoritative.

Fancy words, elegant phrases aren’t Fancy words, elegant phrases aren’t enough if they don’t convey any enough if they don’t convey any information.information.

For ExampleFor Example

Question: “What is virtual memory?”Question: “What is virtual memory?” Vacuous Answer: “Virtual memory is a very Vacuous Answer: “Virtual memory is a very

important memory management technique. important memory management technique. Today, almost all operating systems employ Today, almost all operating systems employ some form of virtual memory. Virtual memory is some form of virtual memory. Virtual memory is implemented by the memory management implemented by the memory management portion of the operating system. It requires portion of the operating system. It requires special computer hardware and software. special computer hardware and software. Computers without virtual memory are not as Computers without virtual memory are not as efficient or user-friendly as computers with efficient or user-friendly as computers with virtual memory…blah, blah, blah.”virtual memory…blah, blah, blah.”

General DirectionsGeneral Directions

Bring several pens/pencilsBring several pens/pencils Write only on the paper I give you.Write only on the paper I give you. Nothing on your desk but writing Nothing on your desk but writing

implements, eraser, test paperimplements, eraser, test paper Once the test starts, DO NOT SPEAK TO Once the test starts, DO NOT SPEAK TO

ANYONE BUT ME!ANYONE BUT ME! Don’t leave the classroom during the test.Don’t leave the classroom during the test.

GOOD LUCK!