Preparing your students for successon the AP CS Principles Exam Dan Garcia (UC Berkeley) & Baker Franke (code.org) 2017-04-05 @ 4:30pm PST This document: tinyurl.com/APCSPExamSuccess YouTube webinar: youtu.be/ncGwuKu2Gp8 Agenda ● Overview ● Sources of Questions ● Resources ● Vocabulary that our students didn’t know ● Tips for doing well Overview ● (from CED p.70) “The end-of-course AP Computer Science Principles Exam is 2 hours long. It is a paper and pencil exam and includes 74 multiple-choice questions. There are two types of multiple- choice questions: ○ Single-select multiple-choice questions: Students select one answer from among four options. ○ Multiple-select multiple-choice questions: Students select two answers from among four options.” ● (from CED p. 82) “Approximate Percentage of Multiple-Choice Questions ○ Big Idea 1: Creativity: 0% ○ Big Idea 2: Abstraction: 19% ○ Big Idea 3: Data and Information: 18% ○ Big Idea 4: Algorithms: 20% ○ Big Idea 5: Programming: 20% ○ Big Idea 6: The Internet: 13% ○ Big Idea 7: Global Impact: 10%” ● Date: May 5th (Cinco de Mayo) Sources of Questions ● CB Official ○ 22 questions from original CED (p. 83) ○ 74 questions from AP CSP Sample Exam (ask CB for it -- “you get it ‘for free’ once your course has passed the CB audit”, it’s a teacher resource - Baker) ■ Baker’s (lightweight) breakdown of 74 questions on practice exam ● Unofficial ○ Cengage Book: Fast Track to a 5: Preparing for AP® Computer Science Principles Examination ■ John Hajel: “There are errors (some in the questions, some in the answers), be aware” ■ Eric Romin’s “VERY incomplete list of issues that a few teachers have put together” ○ albert.io sample questions ○ CodeHS CSP review course. Or get started from here: https://codehs.com/playlist/1780/ (It requires a CodeHS login, but that's free.) ○ Abstracting CS’s practice test, analysis by Big Idea, extra probs: http://www.abstractingcs.com Resources ● Dan Garcia’s Snap! project to explore the code from the reference sheet and make your own Robot problems! (tinyurl.com/snapcsp) ● Baker Franke’s APBML (AP Blocks Markup Language) to make up your own questions ● Code.org’s resources: Widgets, Lossy Text Compression, and Internet Videos ● Blown To Bits Appendix (incredible description of how the Internet works) ● Caroline Meeks’ AP CSP Exam Review Vocab Quizlet ○ Myra Deister’s AP CSP Final Exam Review Quizlet ○ Mike Phelan’s AP Computer Science Principles Review Kahoot Vocabulary Review ● While we don’t recommend you make your students memorize the EKs, there were vocabulary words that our students have struggled with and didn’t know coming into the course. Make sure they know these! ● Big Idea 2: Abstraction ○ Overflow (error that results when the number of bits is not enough to hold the number, like a car’s odometer “rolling over”), Round-off (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) ● Big Idea 3: Data and Information ○ Lossy (Compressing data in a way that throws some data away and makes it almost impossible to recover the original, great compression, like JPEG images) ○ Lossless (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) ■ Check out the Aloe Blacc video that sits in front of the text compression lesson which you can find on the widgets page ○ Metadata (data about data, like a camera storing the location, aperture, shutter speed, etc. for a digital photo) ● Big Idea 4: Algorithms ○ Sequencing (code flows line by line, one after another, like a recipe) ○ Selection (a boolean condition to determine which of two algorithmic paths are taken, aka if-then) ○ Iteration (using a looping control structure, like while, for, foreach, repeat, repeat-until, etc.) ○ Reasonable time (polynomial in the number of steps an algorithm takes in the worst case based on the input size) ○ Not reasonable time (Usually exponential in the number of steps, like doubling every time your input grows by one) Heuristic (using a “rule” to guide an algorithm, like always walking toward the north star if you were stuck in a forest) ○ Undecidable (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) ○ Linear vs binary search (Going one by one vs starting in the middle and going left/right like looking for a word in the dictionary -- binary search requires the list to be sorted in order) ● Big Idea 5: Programming ○ APIs (Application Programming Interface, how you define libraries and call them) ● Big Idea 6: The Internet ○ Essentially every EK was a new idea...all of them! (Blown to Bits Appendix is a good resource) ● Big Idea 7: Global Impact ○ Citizen Science (Lots of people to help with a scientific project, like asking everyone around the world to count the butterflies they see one day) ○ Cloud Computing (Using distributed calculations and/or storage for big data or a web application) ○ Crowdsourcing (Asking lots of users online to help with something, like funding a project, or running SETI@Home to help look for extraterrestrial signals) ○ Creative Commons (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) ○ Open Access (A policy that allows people to have read access to things, e.g., libraries or online data) ○ Moore’s Law (The # of transistors on a chip doubles every two years) ○ Peer-to-peer networks (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) ○ Digital divide (The idea that some communities / populations have less access to computing than others) Tips for doing well ● Do a lot of practice questions! ● Know the vocabulary’ ● General test-taking strategies ○ Eliminate obvious wrong answers ○ Read the whole question and all the answers before choosing ○ Don’t get bogged down on one question, keep a good pace and skip the hard ones to return to later. ○ Remember what section you’re in! Sometimes you have to choose just one, sometimes you have to choose two.