A-LevelComputer ScienceProgramming9618/22 · Oct/Nov 2022 · Q111 Marks

Refer to the insert for the list of pseudocode functions and operators. 1 (a) A programmer is developing an algorithm to solve a problem. Part of the algorithm would be appropriate to implement as a subroutine (a procedure or a function).

(a)(i)State two reasons why the programmer may decide to use a subroutine. 1 2[2]
(a)(ii)A procedure header is shown in pseudocode: PROCEDURE MyProc(Count : INTEGER, Message : STRING) Give the correct term for the identifiers Count and Message and explain their use. Term Use[2]
(b)The algorithm in part (a) is part of a program that will be sold to the public. All the software errors that were identified during in-house testing have been corrected. Identify and describe the additional test stage that may be carried out before the program is sold to the public. Test stage Description[4]
(c)Part of an identifier table is shown: Variable Type Example value FlagDay DATE 23/04/2004 CharList STRING "ABCDEF" Count INTEGER 29 Complete the table by evaluating each expression using the example values. Expression Evaluation MID(CharList, MONTH(FlagDay), 1) INT(Count / LENGTH(CharList)) (Count >= 29) AND (DAY(FlagDay) > 23)[3]

Mark scheme

Marking points from the official mark scheme (Oct/Nov 2022). The mark or mark type is shown in brackets.

[2] (a)(i) One mark for each point (Max 2): • When a task which is repeated / reused / performed in several places • When a part of an algorithm performs a specific task • Reduces complexity of program / program is simplified // subroutine already available • Testing / debugging / maintenance is easier
[2] (a)(ii) One mark for each part: Term: Parameter(s) Use: to pass values / arguments to the procedure
[4] (b) One mark for test stage, one mark for each description point (Max 3 for Description) Test stage: Beta testing Description: 1 Testing carried out by a small group of (potential) users 2 Users will check that the software works as required / works in the real world / does not contain errors 3 Users will feedback problems / suggestions for improvement 4 Problems / suggestions identified are addressed (before the program is sold)
[3] (c) One mark per row: Expression Evaluation MID(CharList, MONTH(FlagDay), 1) 'D' INT(Count / LENGTH(CharList)) 4 (Count >= 99) AND (DAY(FlagDay) > 23) FALSE

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