Summative Assessment — Karel Programming

In Karel, what is a function (procedure) and how is it different from a command in the API? Explain with: how it's defined, how it's called, and why naming/indentation matter.

Time allowed: 1 minute

• A function in Karel is a user-defined set of instructions, defined with a name and called in the program, while API commands are built-in; naming and indentation help organize and clarify code.

• A function in Karel is a built-in command, while API commands are user-defined; naming and indentation do not matter.

• A function in Karel is only used for moving Karel, while API commands are for turning; naming and indentation are not important.

• A function in Karel and an API command are the same, and there is no difference in how they are defined or called.

Which of the following best defines sequencing, selection, and iteration in Karel, and provides a correct example for each?

Time allowed: 1 minute

• Sequencing is executing steps in order, selection is making decisions, iteration is repeating actions; e.g., move; if(frontIsClear()){move();}; repeat(3){move();}

• Sequencing is repeating actions, selection is executing steps in order, iteration is making decisions; e.g., repeat(3){move();}; move; if(frontIsClear()){move();}

• Sequencing is making decisions, selection is repeating actions, iteration is executing steps in order; e.g., if(frontIsClear()){move();}; repeat(3){move();}; move

• Sequencing, selection, and iteration all mean executing steps in any order; e.g., move; turnLeft(); putBeeper();

Which of the following best describes Karel’s API and provides three commands from the API with their expected effects?

• Karel’s API is a set of commands for controlling the Karel, such as move() to move forward, turn_left() to turn left, and put_ball() to place a ball

• Karel’s API is a list of programming languages, such as Python, Java, and C++, each with its own syntax.

• Karel’s API is a collection of mathematical formulas used to solve equations, like add(), subtract(), and multiply().

• Karel’s API is a set of drawing tools, such as drawCircle(), drawSquare(), and erase().

An interface in this context is:

• A set of commands that allows your program to interact with the Karel world.

• A graphical representation of Karel's movements.

• A physical device used to control Karel.

• A programming language unrelated to Karel.

Abstraction can be explained as hiding complex details and showing only the necessary features. Which of the following is a correct example of abstraction in real life and in Karel?

Time allowed: 1 minute

• A TV remote (real life) and using a helper function to turn right in Karel (Karel example)

• A car engine (real life) and writing all code in main (Karel example)

• A book cover (real life) and repeating the same code everywhere in Karel (Karel example)

• A pencil (real life) and not using any functions in Karel (Karel example)

Top-down design and decomposition are important concepts in planning a larger Karel program. You have 1 minute to answer: Which statement best defines their relationship?

• Top-down design involves breaking a problem into smaller parts (decomposition) to make programming easier.

• Decomposition means writing code without any structure, while top-down design ignores decomposition.

• Top-down design and decomposition are unrelated concepts in programming.

• Decomposition is only used after a program is fully written, not during planning.

The behavioral difference between 'if' and 'if/else' in Karel is that 'if' only executes code if a condition is true, while 'if/else' executes one block if the condition is true and another if it is false. You have 1 minute to answer: Which situation requires 'if/else' rather than just 'if'?

• When you need to perform one action if a condition is true and a different action if it is false.

• When you only need to check a condition and do nothing if it is false.

• When you want to repeat an action multiple times.

• When you want to check multiple unrelated conditions.

For loop vs while loop in Karel: When is each more appropriate?
Time allowed: 1 minute

• For loop is best for a known count, while loop is best for an unknown distance.

• For loop is best for an unknown distance, while loop is best for a known count.

• Both loops are only used for unknown distances.

• Both loops are only used for known counts.

Which of the following lists three debugging strategies you can use in Karel (no IDE) and the type of bug each helps catch?

Time allowed: 1 minute

• Tracing code execution (flow), checking pre/post conditions (logic), reviewing syntax rules (syntax)

• Using print statements (syntax), running code backwards (logic), ignoring errors (flow)

• Guessing the output (logic), skipping lines (syntax), random changes (flow)

• Only running the code once (syntax), never checking logic (logic), avoiding flow analysis (flow)

Which of the following best illustrates the use of sequencing, selection, and iteration in the mini-algorithm goal: “Scan a hallway, pick all balls on any tile, then stop.”?

Time allowed: 1 minute

• Sequencing: Move forward; Selection: If ball present, pick up; Iteration: Repeat until end of hallway.

• Sequencing: Pick up ball; Selection: Move forward if no ball; Iteration: Stop immediately.

• Sequencing: Repeat until end; Selection: Pick up ball if present; Iteration: Move forward once.

• Sequencing: If ball present, pick up; Selection: Move forward; Iteration: Stop if no ball.