A company copies a teenager's original app, a U.S. work. According to the U.S. Copyright Office, what must be done before an infringement lawsuit can be brought?Answer: The app must be registered with the Office. Source: U.S. Copyright Office, Frequently Asked Questions, Copyright in General, "Do I have to register with your office to be protected?". Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.1 methods of protecting intellectual property rights.
A developer adds a text description to every image on a school site so that a screen reader can announce it to blind visitors. Which design goal is this?Answer: Accessibility. Source: K-12 Computer Science Framework, Glossary, "accessibility". Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), A.2 obstacles to equal access to computing.
A district moves all homework to an online platform. Students in one rural area have no home broadband and fall behind. Which term names this gap?Answer: The digital divide. Source: Wikipedia, "Digital divide". Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), A.2 obstacles to equal access to computing.
Show all 53 questions (50 more)
Impacts of computing, continued
A photographer posts a picture marked CC BY-NC. Which use does that license allow without asking her?Answer: Adapting it for a free class handout, with credit. Source: Creative Commons, About CC Licenses, CC BY-NC. Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.1 methods of protecting intellectual property rights.
A shopping site recognizes a returning browser and shows the cart left there last week. Which mechanism makes this possible?Answer: A cookie. Source: NIST Computer Security Resource Center glossary, cookie. Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.3 methods digital services use to collect information about users.
A teacher finds a lab diagram marked CC BY-ND. Which use breaks that license?Answer: Posting a cropped and relabelled version, with credit. Source: Creative Commons, About CC Licenses, CC BY-ND. Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.1 methods of protecting intellectual property rights.
Under the NIST definition, which record held by a tutoring app is personally identifiable information?Answer: A user's name stored with a date and place of birth. Source: NIST Computer Security Resource Center glossary, personally identifiable information. Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.3 privacy and security issues.
Which condition must a license meet under the Open Source Definition?Answer: The program must include source code and allow its distribution. Source: Open Source Initiative, The Open Source Definition, 2. Source Code. Outline: ETS Study Companion for Praxis Computer Science (5652), I. Impacts of Computing (15%), B.1 methods of protecting intellectual property rights.
Algorithms and computational thinking 13
A delivery app must order 40 stops. Trying every order would take far too long, so it uses a method that quickly gives a good route, though not always the shortest. What is such a method called?Answer: A heuristic. Source: NIST, Dictionary of Algorithms and Data Structures, "heuristic". Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.1 limitations of computing and heuristic solutions.
A game draws its "random" numbers from an algorithm that starts with a seed, and the same seed always gives the same sequence. What are these numbers?Answer: Pseudorandom. Source: NIST Computer Security Resource Center glossary, pseudorandom number generator. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.4 randomization.
A procedure countdown(n) prints n and then calls countdown(n − 1). It has no other statements. What is missing?Answer: A base case that stops the calls. Source: NIST, Dictionary of Algorithms and Data Structures, "recursion". Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.3 parts of a recursive algorithm.
A procedure draws a square with sides of 50 pixels. A programmer wants one procedure that draws a square of any size. Which detail should become a parameter?Answer: The length of a side. Source: K-12 Computer Science Framework, Glossary, "parameter" and "abstraction". Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), A.1 abstraction.
A recursive procedure f(n) returns 1 when n is 1 or less. Otherwise it returns 2 × f(n − 1) + 1. What does f(4) return?Answer: 15. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.3 simple recursive algorithms.
A sorted list holds 500 names. At most how many names does a binary search compare with the target before it finds the name or shows it is absent?Answer: 9. Source: NIST, Dictionary of Algorithms and Data Structures, "binary search"; the count was recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.2 searching algorithms.
A table pairs inputs 1, 2, 3 and 4 with outputs 3, 7, 11 and 15. Which rule produces the outputs from an input n?Answer: 4n − 1. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), A.2 pattern recognition.
An algorithm in plain words: set total to 0 and count to 1. While count is 4 or less, add count × count to total, then add 1 to count. Output total. What is the output?Answer: 30. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), A.4 algorithms expressed in multiple formats.
For an input of 1,024 items, about how many steps does an algorithm take if its running time grows as log2 n?Answer: 10. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.1 linear, quadratic, exponential and logarithmic algorithms.
Insertion sort takes the items 5, 2, 9, 1 one at a time and puts each in order among those already taken. What does the sorted part hold once three items have been taken?Answer: 2, 5, 9. Source: NIST, Dictionary of Algorithms and Data Structures, "insertion sort"; the trace was recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.2 sorting algorithms.
What is the decimal value of the binary number 101101?Answer: 45. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), A.3 number base conversion.
Which of these four numbers is the largest?Answer: Binary 110010. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), A.3 number base conversion.
Which statement about the halting problem is correct?Answer: No algorithm can decide whether any arbitrary program halts. Source: NIST, Dictionary of Algorithms and Data Structures, "halting problem". Outline: ETS Study Companion for Praxis Computer Science (5652), II. Algorithms and Computational Thinking (25%), B.1 problems that cannot be solved by a computer.
Programming 17
A procedure should return true for ages 13 through 19. Which set of test ages is the most useful?Answer: 12, 13, 19, 20. Source: Wikipedia, "Boundary-value analysis". Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.5 debugging techniques and appropriate test cases.
A program adds the floating-point numbers 0.1 and 0.2, and the test sum = 0.3 turns out false. Which kind of error explains it?Answer: Round-off error. Source: Python Software Foundation, The Python Tutorial, 15. Floating-Point Arithmetic: Issues and Limitations. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.2 types of error produced by a code segment.
A program evaluates 20 − 18 / 3 * 2 + 4 with the usual operator precedence. What is the result?Answer: 12. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.5 standard operators and operator precedence.
A program must find a student's locker number from the student's ID, with no searching through a list in order. Which data structure fits best?Answer: A dictionary (map). Source: NIST, Dictionary of Algorithms and Data Structures, "dictionary". Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.4 dictionaries/maps, stacks and queues.
A programmer's high-level source file is turned into a low-level file for the processor before the program is ever run. Which tool does this translation?Answer: A compiler. Source: Wikipedia, "Compiler". Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.14 program compilation and program interpretation.
A sign-up form asks for a new password twice and compares the two entries. It also rejects a birth year of 3024. In the wording of the ETS outline, which is which?Answer: The password check is verification and the year check is validation. Source: ETS Study Companion for Praxis Computer Science (5652), Content Topics, III. Programming (30%), B.9 validating correct input and detecting incorrect input.
An unsigned 8-bit variable can hold 0 to 255. It holds 250 and the program adds 10. The result is stored as 4. What happened?Answer: An overflow. Source: Wikipedia, "Integer overflow"; the wrapped value was recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.2 types of error produced by a code segment.
Class Shape has a method area(). Its subclass Circle defines its own area() with the same name, parameters and return type. What is this called?Answer: Overriding. Source: Oracle, The Java Tutorials, Overriding and Hiding Methods. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.13 overloading and overriding.
Classes Teacher and Student both need a name, an email and a method printBadge(). A programmer writes these once in a class Person and makes both its subclasses. Which benefit of inheritance is this?Answer: Commonly used state and behavior are written once and reused. Source: Oracle, The Java Tutorials, What Is Inheritance?. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.13 benefits of inheritance and encapsulation.
In a language where / between two integers is integer division, what is the value of 17 / 5 + 17 MOD 5?Answer: 5. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.6 integer and floating point division.
n ← INPUT. steps ← 0. WHILE n > 1: n ← n DIV 2, steps ← steps + 1. OUTPUT steps. DIV is integer division. Which input gives the output 3?Answer: 9. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.4 inputs that produce given outputs for a code segment.
On an empty stack a program runs: push 3, push 7, pop, push 5, push 2, pop, pop. Which value is now on top?Answer: 3. Source: NIST, Dictionary of Algorithms and Data Structures, "stack"; the trace was recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.4 dictionaries/maps, stacks and queues.
PROCEDURE gap(a, b): IF a > b THEN RETURN a − b. Otherwise RETURN b − a. What does gap(4, 9) + gap(9, 4) evaluate to?Answer: 10. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), B.1 procedures with parameters and return values.
SUBSTRING(s, start, length) counts the first character as position 1. With s ← "COMPUTER", what is CONCAT(SUBSTRING(s, 4, 3), SUBSTRING(s, 1, 3))?Answer: "PUTCOM". Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.6 sequence of string operations.
total ← 0. FOR i FROM 1 TO 3: FOR j FROM 1 TO i: total ← total + j. What is total when both loops end?Answer: 10. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.4 sequence, selection and iteration.
Which expression is equivalent to NOT (isMember AND total ≥ 50)?Answer: NOT isMember OR total < 50. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.5 Boolean algebra and equivalent Boolean expressions.
x ← 10. REPEAT 4 TIMES: IF x > 6 THEN x ← x − 4, ELSE x ← x + 3. What is x after the fourth pass?Answer: 8. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), III. Programming (30%), A.4 sequence, selection and iteration.
Data 8
A character code turns each letter into a number by a public table that anyone can reverse. What does encryption do that such an encoding does not?Answer: It conceals the data's meaning from those without the means to reverse it. Source: NIST Computer Security Resource Center glossary, encryption. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.2 data encryption and decryption.
A class writes a program in which each student who knows a rumor tells two classmates picked at random each round. Which question can this simulation answer?Answer: About how many rounds pass before most of the class has heard it, under these rules. Source: K-12 Computer Science Framework, Glossary, "simulate; simulation". Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), B.1 simulation and modeling.
A scheme encodes A as 00, B as 01, C as 10 and D as 11. What does 10011100 decode to?Answer: CBDA. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.1 encoding and decoding data.
A school wants to give each of 100 students a different binary code of the same length. What is the least number of bits per code?Answer: 7. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.1 bits and bytes required to store data.
A student must shrink a file of exam scores and later get back every character exactly. Which kind of compression is needed?Answer: Lossless compression. Source: Wikipedia, "Lossless compression". Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.1 lossy and lossless data compression.
A table lists five students: Ana, grade 10, Chess. Ben, grade 11, Chess. Cy, grade 10, Band. Di, grade 10, Chess. Eli, grade 9, Chess. How many rows match grade = 10 AND club = "Chess"?Answer: 2. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), B. manipulation of data.
An uncompressed image is 800 pixels wide and 600 pixels high, and each pixel takes 24 bits. How many bytes does the pixel data take?Answer: 1,440,000. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.1 calculations using bits and bytes.
Spreadsheet cells A1 to A5 hold 4, 9, 2, 9 and 6. What does =COUNTIF(A1:A5, ">5") return?Answer: 3. Source: Worked out from the figures in the question and recomputed. Outline: ETS Study Companion for Praxis Computer Science (5652), IV. Data (15%), A.3 computational tools, including spreadsheets.
Computing systems and networks 7
A data center fits every server with two power supplies, so that one can fail and the server keeps running. Which design idea is this?Answer: Redundancy. Source: K-12 Computer Science Framework, Glossary, "redundancy". Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), computing systems.
A laptop is switched on. One program is loaded before any application can start, and its kernel then stays in memory the whole time. Which program is it?Answer: The operating system. Source: NIST Computer Security Resource Center glossary, operating system. Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), computing systems.
A long video sent across the internet does not travel as one piece. It is sent as many small units of data. What is each unit called?Answer: A packet. Source: K-12 Computer Science Framework, Glossary, "packet". Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), networks and the Internet.
A school makes staff sign in with a password and then a code from a device they carry. Which practice is this?Answer: Multi-factor authentication. Source: NIST Computer Security Resource Center glossary, multi-factor authentication. Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), security of computing systems.
A student types a site's name into a browser, and the browser must first learn the numerical address of the server. Which system supplies it?Answer: The Domain Name System. Source: Wikipedia, "Domain Name System". Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), networks and the Internet.
Which device determines the path that data packets travel from their source to their destination across networks?Answer: A router. Source: K-12 Computer Science Framework, Glossary, "router". Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), networks.
Which network component limits access between two networks according to the local security policy?Answer: A firewall. Source: NIST Computer Security Resource Center glossary, firewall. Outline: ETS Study Companion for Praxis Computer Science (5652), V. Computing Systems and Networks (15%), security of computing systems.
How this list was compiled: Our own questions, written to the content topics of the ETS Study Companion for Praxis Computer Science (5652) (https://www.ets.org/pdfs/praxis/5652.pdf, read 2026-10-13; test page https://praxis.ets.org/test/5652.html): five content categories, Impacts of Computing 15%, Algorithms and Computational Thinking 25%, Programming 30%, Data 15%, Computing Systems and Networks 15%. The bank holds 8, 13, 17, 8 and 7 questions. Every definition was read on 2026-10-13 on the public page the question names: the glossary of the K-12 Computer Science Framework (k12cs.org), the NIST Dictionary of Algorithms and Data Structures (xlinux.nist.gov/dads), the glossary of the NIST Computer Security Resource Center (csrc.nist.gov), Creative Commons (creativecommons.org), the Open Source Initiative (opensource.org), the U.S. Copyright Office (copyright.gov), The Python Tutorial (docs.python.org), The Java Tutorials (docs.oracle.com) and six Wikipedia articles. Every traced or calculated answer was recomputed. Licence: Questions, choices and explanations are original work of this site.
How it works
This free computer science Praxis study guide is 53 practice questions of our own, spread over the five content categories of test 5652 as ETS weights them. It is unofficial and not affiliated with, endorsed by or sponsored by ETS.
Read the full guide
What test 5652 covers
By the ETS Study Companion read October 13, 2026, Computer Science (5652) has 100 selected-response questions in 3 hours: Impacts of Computing 15%, Algorithms and Computational Thinking 25%, Programming 30%, Data 15%, Computing Systems and Networks 15%. This bank holds 8, 13, 17, 8 and 7 questions.
Code without one language
ETS says the test is not designed to be aligned with any particular computer science curriculum. The code questions here are written in plain pseudocode, so each trace can be followed line by line.
Where the answers come from
Each definition names the public page it was read on: the K–12 Computer Science Framework glossary, two NIST glossaries, Creative Commons, the U.S. Copyright Office and others. Every traced or calculated answer was recomputed.
On the real test some questions ask for more than one answer choice. Here every question has four choices and one right answer.
ETS says the test may contain some questions that do not count toward your score.
Questions and answers
Is there a free practice test for Praxis Computer Science?
Yes, this one. All 53 questions are free and need no account. They were written for this site from the ETS content topics for test 5652, and none repeats or rewords a real test question or an ETS sample question.
What should a Praxis Computer Science 5652 study guide cover?
The five categories of the ETS outline. Programming and algorithms together are 55% of the test, so tracing code, converting number bases and counting the steps of a search deserve the most time. Impacts of computing, data and networks share the rest.
Is this a Praxis 2 computer science practice test?
It practices the Praxis subject test named Computer Science, code 5652. The official outline is the free ETS Study Companion, and this page follows its five categories.
What score do I need to pass Praxis Computer Science?
ETS says passing scores are not set by ETS and vary by state. Look up the qualifying score of your state or licensing agency. A result here is a count of right answers and carries no verdict.