A-LevelComputer ScienceSoftware development9618/12 · May/June 2023 · Q716 Marks

A software developer is working in a team writing a program for a client.

(a)(i)Define the term program library.[2]
(a)(ii)Explain two benefits to the developer of choosing to create a Dynamic Link Library (DLL).[4]
(b)The development team needs to use a translator whilst writing the program for the client. Identify whether an interpreter or a compiler would be more appropriate at this stage of the program development. Justify your choice. Translator Justification[3]
(c)The development team uses an Integrated Development Environment (IDE). Complete the table by describing the typical features found in an IDE. Feature Description Breakpoints Dynamic syntax checks Context-sensitive prompts Single stepping[4]
(d)One section of the program being developed will convert user's speech into commands. Explain how Artificial Intelligence (AI) can be used in this program.[3]

Mark scheme

Marking points from the official mark scheme (May/June 2023). The mark or mark type is shown in brackets.

[2] 1 mark each to max 2 • Set of pre-written / pre-compiled / pre-tested subroutines • ... which can be called in other programs • ... by installing/importing the library
[4] 1 mark for each bullet point. Mark in pairs; 1 mark for a benefit and 1 mark for an appropriate expansion • (main) memory requirements for program is reduced • as dynamic link library is loaded only once / when required • the executable file size of the program using the DLL will be smaller • because the executable does not contain (all) the library routines • maintenance not needed to be done by the programmer • because the DLL is separate from program • no need to recompile the main program when changes are made to DLL • because changes / improvements/ error correction to the DLL file code are done independently of the main program • A single DLL file can be made available to several application programs • Saving space in memory / easing the pressure on memory
[3] No mark for choice. 1 mark each to max 3 for justification Interpreter • Allows the developer to make real-time changes • so the program can be debugged at each stage • the effect of any changes made by the developer can be seen immediately • The developer can test when incomplete • so small parts can be tested without having to test the rest of the program • if one section does not work others can still be tested • To avoid dependent errors Compiler • The developer can debug multiple errors simultaneously • Produces an executable file • so that the developer can test the program multiple times without recompiling
[4] 1 mark each Breakpoints: Stop the code at a specific line to check the current progress / values Dynamic syntax checks: Highlight / underline / colour syntax errors as the code is entered Context-sensitive prompts: Suggest the code to add // automatically complete statements Single stepping: Run the code one line at a time so the values can be checked
[3] 1 mark each to max 3 • Uses speech recognition • ... which identifies key phrases / words spoken • ... and matches these to a database • ... and generates the most likely sentence / command / word