A Level Computer Science OCR Practice Exam

When code optimization is executed improperly, one of the main outcomes is that the program may exhibit unexpected errors. Poor optimization techniques can lead to changes in the program's behavior. For instance, the optimizations might inadvertently alter the logic of the code, introduce bugs, or create conflicts that were not present before. This can happen if assumptions made during the optimization process do not hold true in the context of how the code operates, especially if there is a misunderstanding of data dependencies or control flow.

In contrast, the other outcomes do not necessarily occur as a result of incorrect optimization. While running faster might be a goal of optimization, incorrect methods usually slow down the program or produce errors rather than improve performance. Furthermore, optimization can sometimes make code less readable if it utilizes complex or obscure techniques instead of simplifying the logic. Lastly, the runtime remaining unchanged is unlikely if the code has been optimized in some way, but incorrect optimizations typically lead to more significant issues rather than leaving runtime unaffected.