Working in Python · AP Computer Science Principles ↳ Vocabulary by Chapter ↳ A-Z Glossary (merged)

AP CSP Vocabulary Coverage

A course-curated AP CSP vocabulary list — prioritized by real instructional cost, not just exam frequency — matched term by term against what this book actually teaches.

38/144
terms taught in this book
11/144
planned elsewhere in the course
95/144
Little Brother's territory, or an open gap

Where this list comes from

Sourced from this course's own data/ap-vocabulary-source.md — a curated, instructional-priority list, not a straight AP CSP glossary (the CED has none of its own; see alignment/glossary-map.md). Term names and frequency flags draw on a community-compiled study list (apcsexamprep.com) and Khan Academy's AP CSP vocabulary review; every definition here is rewritten, not copied. The Tier classification (Concept / Label / Fact) and WR flag (written-response prompt language) are this course's own addition, driven by an actual measured gap: last year, Create Task work was near-perfect but exam-day written response was not.

C Concept — genuinely new idea, needs instruction time L Label — AP's name for something already taught, ~90 seconds F Fact — lookupable, no warm-up slot needed
★ high-frequency (apcsexamprep.com) ✓ in Khan Academy's review ✎ written-response prompt language

Deliberately excluded: the exam's pseudocode notation block (DISPLAY, INPUT, REPEAT n TIMES, REPEAT UNTIL, INSERT, APPEND, REMOVE, LENGTH, FOR EACH) and the Robot commands — the exam supplies a reference sheet, so these are recognition items, not vocabulary. MOD, RANDOM(a, b), and RETURN are kept; each carries a concept, not just a keyword.

Working in Python ~185 glossary terms AP CSP 144 curated terms 38 shared terms function, list, loop, variable, index, module, debugging, procedure, MOD, RANDOM … TCP/IP, encryption, bias, bandwidth, heuristic, bit, simulation, undecidable problem …

Symbolic, not literal — a Venn diagram plotting all 329 words individually would be illegible. Circle sizes and overlap are illustrative, not area-proportional.

Big Idea 1 — Creative Development

CRD

25 terms — 8 in book, 3 planned, 0 Little Brother, 14 gap.

TermTierHFKAWRWiPWiP termCh.DefinitionNote
AlgorithmC gapA finite sequence of steps that solves a problem or completes a task. Can be written in English, pseudocode, or code.Students conflate this with “program.” An algorithm is the plan; a program is one implementation of it. (WiP: Used constantly in the book's own prose but never itself a glossary headword.)
ProgramL  gapA collection of statements that performs a task when run.(WiP: Same as Algorithm: everywhere, never its own headword.)
Program purposeC  gapWhat problem the program solves or what need it serves — the *why*.Not on any published list. It is the literal opening of WR1 and students answer it vaguely. Teach purpose/function/input/output as one four-part frame, not four terms.
Program functionC  gapWhat the program does when it runs — the *what*, described behaviorally.Students describe features instead of behavior. “It has a scoreboard” is not a function statement.
Program inputC  gapData the program receives while running: user action, file, sensor, network, another program.Must be *at runtime*. Hard-coded values are not input.
Program outputC  gapWhat the program produces: display, sound, file, movement, data sent elsewhere.
Code segmentL  gapA portion of a program, one or more lines, treated as a unit.WR2 asks about a “code segment” by name. Students need to know they are being asked to point at specific lines.
Computing innovationC  plannedA product, service, or concept that includes a program as an integral part of its function. May be physical, software, or conceptual.The “includes a program” clause is load-bearing. A bridge is not a computing innovation; a bridge with a load-monitoring system is. (WiP: Create Performance Task.)
CollaborationL   plannedWorking with others to develop a computing innovation; benefits from varied perspectives and skills.(WiP: Lab pair work + Create PT.)
Pair programmingL   plannedTwo programmers at one workstation: one drives, one reviews and thinks ahead.Already the classroom norm. Just attach the name. (WiP: Create PT / classroom practice.)
Program documentationL  in bookdocstring4Written description of what a segment, procedure, or program does and how it was built.
CommentsL  in bookcomment2Documentation written inside the code for human readers; ignored at execution.Comments are graded in this course, so the term is already lived.
DebuggingC   in bookdebugging1The process of finding and fixing errors in a program.Missing from all three published lists despite being the daily activity. Name it so students can talk about it.
Syntax errorC in booksyntax error1A violation of the language's grammar rules; the program typically will not run at all.Teach as a three-way contrast with logic and run-time, not separately.
Logic errorC in booksemantic error2The program runs but produces the wrong result.Hardest of the three to detect, because nothing complains. (WiP: Same idea, different name.)
Run-time errorC  in bookruntime error2An error that appears only during execution, such as dividing by zero.Python raises these as tracebacks; connect the term to what they already see on screen.
Overflow errorC gapThe value is outside the range representable in the available bits.Python's ints are arbitrary precision, so students never see this natively. Needs a deliberate demo. (WiP: Structurally can't arise in the language the book teaches.)
Roundoff errorC  gapLoss of precision because a fixed number of bits cannot represent a real number exactly.`0.1 + 0.2` in the console does this work for you.
TestingL   in booktest discovery18Verifying a program behaves correctly by running it with defined inputs.(WiP: Also ch. 7's pass/fail vocabulary.)
Test caseC  gapA specific input paired with its expected output. Good sets include typical, boundary, and edge values.Maps directly onto the doctest format and Bootstrap's design recipe (contract → examples → definition). Boundary and edge are the part students omit. (WiP: The practice exists in exercises; the term is never named.)
Hand tracingC   gapManually stepping through code, tracking variable values, to locate an error.Python Tutor is the visualization; hand tracing is the paper version, and the exam only has paper.
Iterative developmentC  gapRepeated cycles of build, feedback, and revision; earlier phases get revisited.Teach with incremental as a pair — students merge them into “we kept working on it.” (WiP: Distinct from Incremental, which the book does name.)
Incremental developmentC  in bookincremental development6Breaking a problem into pieces and confirming each works before integrating.
EventL   gapAn action supplied to a program as input: key press, click, sensor reading.(WiP: Already a known, real gap.)
Event-driven programmingL   gapStatements execute in response to events rather than in top-to-bottom sequence.The micro:bit opener and CMU-style graphics both demonstrate this before the term is needed. (WiP: Every program in this book runs top to bottom.)

Big Idea 2 — Data

DAT

22 terms — 2 in book, 0 planned, 0 Little Brother, 20 gap.

TermTierHFKAWRWiPWiP termCh.DefinitionNote
BinaryL  gapBase-2 representation using only 0 and 1.(WiP: Partial touchpoint in the Pico/MicroPython I2C unit; not this book.)
BitF  gapA single binary digit.(WiP: Partial touchpoint in the Pico/MicroPython I2C unit (byte/hex notation).)
ByteF  gapEight bits.(WiP: Partial touchpoint in the Pico/MicroPython I2C unit (byte/hex notation).)
HexadecimalF   gapBase-16, using 0–9 and A–F; four bits per digit.Keep for the color-code and CRC32 work, not for the exam. (WiP: Partial touchpoint in the Pico/MicroPython I2C unit (byte/hex notation).)
DecimalF   gapBase-10.Cut candidate. Earns a glossary row only for symmetry with binary and hex.
AbstractionC in bookencapsulation / generalization4, 9, 10, 11Reducing complexity by exposing essential features and hiding implementation detail.The single most important word in the course and the one students define circularly. Every other abstraction term below is a special case of this one.
Analog dataC  gapValues that vary continuously and smoothly.Teach as a contrast pair with digital; separately they are near-empty.
Digital dataC   gapValues represented in discrete steps, ultimately as bits.
SamplingC   gapApproximating an analog signal by measuring it at regular intervals.Rate and bit depth are the two knobs. Students think only about rate.
Lossless compressionC gapReduces size while allowing exact reconstruction of the original.Contrast pair with lossy. The exam tests the *choice between them*, not the definitions.
Lossy compressionC gapReduces size further, but only an approximation can be recovered.
MetadataC gapData describing other data: creation date, size, author, location, format.Photo EXIF is the demo that lands. Connects directly to the *Little Brother* and PII threads. (WiP: Already flagged as uncarried under AP topic 2.3.)
DataF   gapValues that can be stored and processed by a program.Cut candidate — near-free definition.
InformationC  gapMeaning, patterns, or insight extracted from data.Taught only as the contrast with data. That contrast is genuinely tested.
Data setF   gapA collection of related data organized for analysis.
CorrelationC  gapAn association between two variables where changes in one accompany changes in the other.The whole lesson is “correlation is not causation,” and it is worth the full period.
Data cleaningC  gapMaking data uniform and consistent without changing its meaning.Students think this means deleting rows they dislike. It does not.
Data filteringL   in bookfiltering10Selecting a subset of data by defined criteria.
ASCIIF   gapA 7-bit character encoding covering 128 characters.
UnicodeF   gapA character encoding standard covering the world's writing systems; extends ASCII.
RGBF   gapColor represented as red, green, and blue channels, typically 0–255 each.
PixelF   gapThe smallest addressable color element of a display or image.

Big Idea 3 — Algorithms and Programming

AAP

43 terms — 28 in book, 8 planned, 0 Little Brother, 7 gap.

TermTierHFKAWRWiPWiP termCh.DefinitionNote
VariableL in bookvariable2A named location holding a value that can change through assignment.
ConstantL   gapA named value that does not change during execution.(WiP: Python has no language-level constant.)
Data typeL   in booktype1The classification of a value, determining what operations apply.
IntegerF   in bookinteger1A whole number.
StringL   in bookstring1An ordered sequence of characters.
BooleanL   in bookboolean expression5A value that is either true or false.
Boolean expressionC  in bookboolean expression5An expression that evaluates to true or false.Distinct from the Boolean *type*. Students who only know the type cannot parse “the Boolean expression in line 4.”
ExpressionL   in bookexpression1A combination of values, variables, operators, and calls that evaluates to a single value.
AssignmentL   in bookassignment statement2Storing a value in a variable.Pseudocode uses `←`. Recognition only; they never have to write it.
ListC in booklist9An ordered sequence of elements, each reachable by index.**Indices start at 1 in College Board pseudocode and 0 in Python.** This is the single biggest trap for a Python-first cohort. Attach the convention to this row rather than making it its own term.
ElementL  in bookelement9One item stored in a list.Distinct from index. WR2 prompts use both words in one sentence.
IndexL   in bookindex8The position of an element within a list.See the List note.
SubstringF   gapA contiguous portion of a string.(WiP: `slice` (ch. 8) is the mechanism; the word itself isn't a headword.)
ConcatenationF   in bookconcatenation1Joining strings end to end.
SequencingL gapExecuting steps in the order written.Tier L, but they must be able to *name* it — the exam asks which construct a segment demonstrates. (WiP: The default behavior of every program in the book; never named as its own concept.)
SelectionL in bookconditional statement5Choosing between paths based on a condition.(WiP: The single biggest name swap between this book and the exam.)
IterationL in bookloop3, 7Repeating steps a set number of times or until a condition is met.`REPEAT UNTIL (condition)` **exits** when the condition is true. Python's `while` **continues** when true. Inverted sense; put this note on the row rather than teaching the keyword. (WiP: Definite iteration (`for`) only — this book has no `while` loop at all.)
Nested conditionalL   in booknested conditional5A conditional inside another conditional.
Compound conditionalC  in booklogical operator5A single condition combining multiple Boolean expressions with AND, OR, or NOT.Not covered by “nested.” Students merge the two and then mis-answer questions that hinge on the difference. (WiP: The mechanism is taught; the AP-specific label isn't used verbatim.)
Relational operatorsF   in bookrelational operator5Comparison operators: =, ≠, >, <, ≥, ≤.
Logical operatorsL   in booklogical operator5AND, OR, NOT.The truth-table drill is worth one warm-up cycle, especially NOT applied to a compound.
MODC   in bookmodulus operator5The remainder after integer division.Kept despite looking like notation — the concept is tested. Even/odd and cycling are the two uses. Negative operands behave unintuitively; worth a distractor. (WiP: `%` here; `MOD` on the exam reference sheet.)
Infinite loopL   gapA loop whose ending condition never becomes true.(WiP: “Infinite recursion” (ch. 5) is the book's only named version of this idea.)
ProcedureCin bookfunction1A named, reusable block of code that performs a task and can be called repeatedly.AP says procedure; Python says function; the ROV course says method. Say all three out loud once, early.
ParameterC  in bookparameter3A named variable in a procedure's definition that receives an input value.Contrast pair with argument. Bootstrap's design recipe maps this cleanly: parameter = domain, return value = range.
ArgumentC  in bookargument2The actual value supplied for a parameter at the call site.Students use the two words interchangeably all year unless corrected in week one.
RETURN statementL  in bookreturn value6Exits a procedure immediately and hands a value back to the caller.The classic misconception is that `return` prints.
Procedural abstractionC  in bookinterface design4Naming a process so it can be used knowing *what* it does without knowing *how*.WR2b routinely asks students to explain this about their own code. Practice on their own Create Task drafts, not on generic examples.
Data abstractionC  in booklist / dict / tuple9, 10, 11Using a data structure, typically a list, to represent related values as one named unit, hiding the individual pieces.Missing from the original list and a standing WR2 target. The exam wants: what does the list represent, and how does using it manage complexity?
ModularityL  gapDividing a program into independent parts each responsible for one aspect.(WiP: encapsulation/generalization (ch. 4) are adjacent, but the word itself is never named.)
Software libraryL  in bookmodule2A collection of pre-written procedures available for reuse.
APIL  gapThe specification of how a library's procedures are called and how they behave.
RANDOM(a, b)C   in bookpseudorandom12Returns a random integer from a to b, **inclusive on both ends**, each equally likely.`random.randint` matches this; `random.random` and `range` do not. Off-by-one on the upper bound is a reliable distractor. (WiP: Python's `random` module, first used in ch. 12.)
SimulationC  plannedAn abstraction of a real phenomenon using varying values to represent changing states, run for a purpose.The exam cares about *why simulate*: cost, risk, time, or repeatability. Students answer “because it's easier.” (WiP: November algorithms block.)
TraversalC gapIterating over the items of a list. Full traversal visits every element; partial stops early.The full/partial distinction is the tested part. (WiP: “Loop variable” (ch. 7) and “element” (ch. 9) are the closest adjacent headwords.)
Linear searchC in booklinear search7Checking each element in turn until the target is found or the list ends.Contrast pair with binary search.
Binary searchC plannedRepeatedly halving a **sorted** list to locate a value.The sorted precondition is the whole question. Students skip it. (WiP: November algorithms block; linear search already taught.)
Algorithmic efficiencyC  plannedAn estimate of the computational resources an algorithm uses as a function of input size.(WiP: November algorithms block.)
Reasonable timeC  plannedRun time that grows polynomially or slower with input size.Khan defines this with polynomial-vs-superpolynomial language, which is more precise than the CED requires. Your students will have seen that framing. (WiP: November algorithms block.)
Unreasonable timeC   plannedRun time that grows exponentially or factorially with input size.(WiP: November algorithms block.)
HeuristicC plannedAn approach that finds a good-enough solution when finding the optimal one is impractical.Flagged in the TODO as needing multiple passes. Not high-frequency on the published list, but genuinely hard, and the definition students give is usually “a guess.” (WiP: November algorithms block.)
Decidable problemC   plannedA yes/no problem for which an algorithm can always produce the correct answer.Contrast pair with undecidable. (WiP: November algorithms block.)
Undecidable problemC  plannedA problem for which no algorithm can always give a correct yes/no answer for every input.Halting problem. Students think it means “very hard.” (WiP: November algorithms block.)

Big Idea 4 — Computer Systems and Networks

CSN

25 terms — 0 in book, 0 planned, 25 Little Brother, 0 gap.

TermTierHFKAWRWiPWiP termCh.DefinitionNote
InternetC  Little BrotherA network of interconnected networks using standardized open protocols.Teach as a contrast pair with the Web. The exam tests the distinction directly.
World Wide WebC  Little BrotherA system of linked pages and files that runs *on top of* the Internet using HTTP.
Computer networkL  Little BrotherInterconnected computing devices able to send and receive data.
Computing deviceF  Little BrotherA physical artifact that can run a program.
Computing systemF   Little BrotherA group of computing devices and programs working together.Distinct from device. Low cost, occasionally tested.
PacketL  Little BrotherA chunk of data carrying metadata such as its destination, sent across a network.
Packet switchingC   Little BrotherSplitting a message into packets that travel independently, possibly by different routes, and are reassembled at the destination.The term is the concept. Having “packet” and “routing” separately does not get you here.
RoutingL   Little BrotherDetermining a path from sender to receiver across a network.
BandwidthF  Little BrotherMaximum data transmittable per unit time, in bits per second.Students confuse this with latency. One sentence fixes it.
ProtocolL  Little BrotherAn agreed set of rules governing system behavior.
Open standardC  Little BrotherA publicly available specification that anyone may implement without permission or fee.This is *why* the Internet scales and interoperates, and it is the expected phrasing in network answers.
TCPF  Little BrotherTransport protocol providing reliable, ordered delivery with retransmission.
UDPF  Little BrotherLightweight transport protocol with minimal error checking; faster, less reliable.
IPF  Little BrotherProtocol for addressing devices and routing packets between them.
IP addressF   Little BrotherThe unique identifier assigned to a device on a network.
HTTP / HTTPSF  Little BrotherThe Web's request/response protocol; HTTPS adds encryption in transit.
DNSF   Little BrotherTranslates domain names into IP addresses.Ch. 16 of *Little Brother* is the DNS tunneling hook, already in the calendar.
RouterF   Little BrotherA device that forwards packets between networks toward their destination.
ScalabilityC Little BrotherA system's ability to keep working acceptably as demand grows.
Fault toleranceC Little BrotherContinuing to operate when components fail.Contrast pair with redundancy: redundancy is the mechanism, fault tolerance is the property. Students state them as synonyms.
RedundancyC   Little BrotherDuplicate paths or components that allow operation to continue after a failure.
Sequential computingL   Little BrotherOperations performed one at a time, in order.Three-way contrast with parallel and distributed.
Parallel computingCLittle BrotherA program split into operations, some performed simultaneously.
Distributed computingC  Little BrotherMultiple devices in different locations running parts of one program.
SpeedupC  Little BrotherSequential time divided by parallel time.The arithmetic question appears nearly every year and it is free points. Drill it.

Big Idea 5 — Impact of Computing

IOC

29 terms — 0 in book, 0 planned, 29 Little Brother, 0 gap.

TermTierHFKAWRWiPWiP termCh.DefinitionNote
Beneficial and harmful effectsC  Little BrotherEvery computing innovation has both, and they can fall on different groups of people.Not a vocabulary word so much as the required shape of an Explore-style answer. Students name only benefits. Belongs in the WR tier regardless.
Digital divideCLittle BrotherUnequal access to computing and the Internet across socioeconomic, geographic, or demographic lines.
BiasC  Little BrotherSystematic unfairness embedded in an algorithm or in the data it was built from.Distinguish bias *in the data* from bias *in the design*. The exam accepts either, but students should know which one they are claiming.
CrowdsourcingL  Little BrotherGathering input, funding, or labor from many people over the Internet.
Citizen scienceF  Little BrotherScientific research carried out partly by volunteers using their own devices.
Machine learningF   Little BrotherSystems that improve at a task from data rather than from explicit programming.Given the classroom AI policy, expect this to generate discussion. Plan for it.
Data miningF   Little BrotherAnalyzing large data sets to find patterns and relationships.
Aggregation of informationC  Little BrotherCombining separately harmless pieces of data to identify or profile a person.Not on any published list. It is the central privacy mechanism in *Little Brother* and the most exam-relevant privacy idea after PII.
AnonymizationC   Little BrotherRemoving identifying details from data — and its limits, since aggregation can re-identify.Pairs with the row above; teach them together or neither.
PIICLittle BrotherInformation that identifies or can be linked to a specific individual.
Intellectual propertyL   Little BrotherCreative or technical work legally owned by its creator.
CopyrightL   Little BrotherThe exclusive right of a creator to reproduce, distribute, and display a work.
Creative CommonsC  Little BrotherA set of public licenses letting a creator pre-authorize specific reuse under stated conditions.The course text is a CC BY-NC-SA fork. Use the actual license notice on their own printed book as the example. (WiP: The book you're teaching from is itself the example.)
Open sourceL   Little BrotherSoftware whose source is public and may be modified and redistributed.
Open accessF  Little BrotherResearch or data made available free of access restrictions.
PlagiarismF   Little BrotherPresenting someone else's work as your own.
EncryptionC Little BrotherEncoding data so only holders of the key can read it.
Symmetric key encryptionC  Little BrotherOne shared key both encrypts and decrypts.Contrast pair with public key. The keygen party already in the calendar is the hook.
Public key encryptionC  Little BrotherA public key encrypts; a different private key decrypts.The asymmetry is the idea. Students describe it as “two passwords.”
AuthenticationL   Little BrotherVerifying that a user is who they claim to be.
Multifactor authenticationL  Little BrotherRequiring evidence from two or more categories: knowledge, possession, inherence.The three categories are the tested part, not the count.
PhishingL Little BrotherTricking a user into revealing private information by impersonating a trusted party.Cluster with malware, keylogging, and rogue AP. One lesson, four terms, high recognition and low cost.
MalwareL   Little BrotherSoftware intended to damage or take control of a system.
Computer virusL  Little BrotherMalware that copies itself, typically by attaching to other programs or files.
KeyloggingL   Little BrotherRecording keystrokes to capture passwords and confidential input.
Rogue access pointL  Little BrotherAn unauthorized wireless access point used to intercept network traffic.
CookiesF  Little BrotherSmall data files stored by a site to track a user's state or behavior.
Digital certificateF   Little BrotherA credential issued by an authority binding a public key to an identity.
Certificate authorityF   Little BrotherAn organization that issues and vouches for digital certificates.

Python-first misconception bank

Where Python's own behavior and the exam's pseudocode disagree — a predictable error, not carelessness. Each row is a ready-made Peer Instruction question.

#DivergencePython beliefExam reality
M1List indexinglist[0] is the first elementPseudocode indices start at 1
M2Loop exit sensewhile cond: continues while trueREPEAT UNTIL (cond) exits when true
M3Random boundsrange(a, b) excludes bRANDOM(a, b) includes both ends
M4Procedure vocabularyfunction, methodprocedure; parameter vs argument
M5Return vs. printprint shows a value, so it “returns” itRETURN hands a value to the caller; nothing is displayed
M6MOD with negativesintuition says the sign follows the dividendworth verifying before asserting either way in class
M7Abstraction“making something simpler”hiding detail behind a name while preserving use
M8Binary searchworks on any listrequires the list be sorted
M9Fault tolerance vs. redundancysynonymsredundancy is mechanism; fault tolerance is the resulting property
M10Data vs. informationsynonymsinformation is what analysis extracts from data