The 2024 AP Computer Science A FRQ 3 assesses students’ ability to traverse and manipulate a 1D ArrayList<String> through two methods:
isWordChain() (3 points) evaluates adjacency checks and substring searches.createList(String target) (6 points) evaluates list construction, filtering, and element transformation.
A maximum of 3 penalty points may be assessed per question for side effects, undeclared variables, or collection‐access errors, but only after points are earned (AP Central, AP Central).Penalty points (1 point each) apply only in parts that have earned credit, up to 3 per question.
[] vs. get()) (AP Central)No penalties are assessed for unambiguous spelling/case issues, missing semicolons/braces when intent is clear, or extraneous non–side‐effect code (AP Central).
public boolean isWordChain() (3 points)| Point | Criterion & Decision Rules |
|---|---|
| 1 | Traverses all adjacent pairs of wordList without bounds errors. • May “return early” if a violation is found ⮕ still earn point if bounds correct (AP Central). |
| 2 | Checks containment: uses indexOf(previous) to determine whether each string contains its predecessor. • May use a single comparison or compare every element to the first ⮕ still earn (AP Central). |
| 3 | Returns correct boolean: false on first failed pair; true if all adjacent pairs satisfy the condition. • Must use both return true and return false in appropriate contexts (AP Central). |
Total for part (a): 3 points (AP Central)
public ArrayList<String> createList(String target) (6 points)| Point | Criterion & Decision Rules |
|---|---|
| 4 | Declares and constructs an ArrayList<String> named (typically) result. • Omission or wrong type (e.g., array) ⮕ no credit (AP Central). |
| 5 | Traverses all elements of wordList without bounds errors. • “Return early” is allowed if bounds remain correct (AP Central). |
| 6 | Identifies strings that begin with the parameter* (current.indexOf(target) == 0). • Must guard against too-short strings or use equivalent substring-with-length check (AP Central). |
| 7 | Constructs new String by removing target.length() characters from the start of each matching element. • Off-by-one or missing substring guard affects point 6 only (AP Central). |
| 8 | Adds at least one correctly constructed String to result via result.add(...). • Must call add on the constructed list; wrong list or wrong method ⮕ no credit (AP Central). |
| 9 | Returns the ArrayList<String> containing all and only appropriately revised strings, in the original order. • No modification of wordList; no extra or missing elements; no early/misplaced return (AP Central). |
Total for part (b): 6 points (AP Central)
This rubric is drawn directly from the 2024 College Board Scoring Guidelines for AP Computer Science A FRQ 3, ensuring precise alignment with official grading standards.