AP Computer Science Principles EXAM AND ANSWERS.

1. error that results when the number of bits is not enough to hold the number, like a car's odometer "rolling over" - ANS-Overflow 2. error that results when the number of bits is not enough to represent the actual number, like 3 digits to represent π as 3.14 - ANS-Round-off 3. Compressing data in a way that throws some data away and makes it almost impossible to recover the original, great compression, like JPEG images - ANS-Lossy 4. Compressing data in a way that preserves all data away and allows full recovery of the original, good compression -- usually not as good as lossy, like PNG images - ANS-Lossless 5. data about data, like a camera storing the location, aperture, shutter speed, etc. for a digital photo - ANS-Metadata 6. code flows line by line, one after another, like a recipe - ANS-Sequencing 7. a Boolean condition to determine which of two algorithmic paths are taken, aka if-then - ANS-Selection 8. using a looping control structure, like while, for, for each, repeat, repeat-until, etc. - ANS-Iteration 9. polynomial in the number of steps an algorithm takes in the worst case based on the input size - ANS-Reasonable Time 10. Usually exponential in the number of steps, like doubling every time your input grows by one - ANS-Not reasonable time 11. using a "rule" to guide an algorithm, like always walking toward the north star if you were stuck in a forest - ANS-Heuristic 12. A problem that is so difficult, we can't ever create an algorithm that would be able to answer yes or no for all inputs, like determining if a user's program run on some input would always stop and not run forever - ANS-Undecidable 13. Going one by one vs starting in the middle and going left/right like looking for a word in the dictionary - ANS-Linear Search 14. requires the list to be sorted in order and then cutting the list in half - ANS-Binary Search 15. Application Programming Interface - ANS-APIs 16. Lots of people to help with a scientific project, like asking everyone around the world to count the butterflies they see one day - ANS-Citizen Science 17. Using distributed calculations and/or storage for big data or a web application - ANS-Cloud Computing 18. Asking lots of users online to help with something, like funding a project, or running SETI@Home to help look for extraterrestrial signals - ANS-Crowdsourcing 19. An alternative to copyright that allows people to declare how they want their artistic creations to be shared, remixed, used in noncommercial contexts, and how the policy should propagate with remixed versions - ANS-Creative Commons 20. A policy that allows people to have read access to things, e.g., libraries or online data - ANS-Open Access 21. The # of transistors on a chip doubles every two years - ANS-Moore's Law 22. A system where one user's computer connects through the Internet to another user's computer without going through an intermediary "centralized" computer to manage the connection - ANS-Peer-to-peer Networks 23. The idea that some communities / populations have less access to computing than others - ANS-Digital Divide 24. Internet Service Provider - ANS-ISP 25. Speech on the Internet goes from the source to an ISP, into the cloud, out of the cloud to another ISP, and to its destination - ANS-How does internet communication arrive at its destination? 1) It can try to control the speaker or the speaker's ISP, by criminalizing certain kinds of speech. But that won't work if the speaker isn't in the same country as the listener. 26. 2)It can try to control the listener, by prohibiting possession of certain kinds of materials. In the U.S., possession of copyrighted software without an appropriate license is illegal, as is possession of other copyrighted material with the intent to profit from redistributing it. 27. 3) The government can try to control the intermediaries. - ANS-How can the government control speech on the Internet? 28. The posters could evade responsibility as long as they remained anonymous, as they easily could on the Internet. - ANS-How can Internet posters evaded being convicted for defamation/slander on the Web? 29. Congress had given the ISPs a complete waiver of responsibility for the consequences of false and damaging statements, even when the ISP knew they were false. - ANS-What has Congress given ISPs relating to an Internet Defamation case? 30. Each protocol interfaces only to those in the layers immediately above and below it, and all data is turned into IP bit packets in order to pass from an application to one of the physical media that make up the network. 31. -Email, Web, Phone 32. -SMTP, HTTP 33. -TCP, UDP 34. -IP 35. -Wire, Fiber, Radio - ANS-Internet Protocol Hourglass 36. Transmission Control Protocol 37. Guarantees reliable transmission by breaking messages into packets, keeping track of which packets have been received successfully, resending any that have been lost, and specifying the order for reassembling the data on the other end. - ANS-TCP 38. User Datagram Protocol 39. provides timely but unreliable message delivery - ANS-UDP 40. Hypertext Transport Protocol 41. which is used for sending and receiving web pages - ANS-HTTP 42. Simple Mail Transport Protocol 43. used for sending email. - ANS-SMTP 44. "End to End," in the Internet, means that the switches making up the core of the network should be dumb—optimized to carry out their single limited function of passing packets. - ANS-What does "End to End" mean in regards to the Internet? 45. Request for Comment 46. Standards adopted through a remarkable process of consensus- building, nonhierarchical in the extreme. Someone posts a proposal, and a cycle of comment and revision, of buy-in and objection, eventually converges on something useful, if not universally regarded as perfect. - ANS-RFC