IGCSE Computer Science Paper 2 Definitions Worksheet: 7c Pseudocode and Flowcharts (Modules 242–253)
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Key terms
Write what each term means, in your own words.
1
Data type error
2
flowchart error
3
Line 3 should be Total ← 0
4
Total ← Total + Value
5
Count ← Count + 1
6
IF Value > Max THEN Max ← Value
7
Average ← Total / Count
8
linear search
9
bubble sort
10
trace table
Answer Key
IGCSE Computer Science Paper 2 · Modules 242–253 · Student wording will vary for definitions
1Data type error — An error caused by using a value its data type does not allow (e.g. a STRING stored in an INTEGER, or an index outside the array) or by using a variable that was never DECLAREd.
2flowchart error — A mistake in a flowchart, such as the wrong symbol shape, a missing Yes or No label, a path that never reaches Stop, or a loop arrow joining the wrong place.
3Line 3 should be Total ← 0 — To suggest a correction, name the wrong line or symbol, say why it is wrong, write the corrected statement, and explain what the fix changes in the algorithm's output.
4Total ← Total + Value — Totalling builds a running total. Set Total ← 0 before the loop, add each Value to Total inside the loop, then OUTPUT Total after the loop has finished.
5Count ← Count + 1 — Adds 1 to Count each time an item meets a condition. Put it inside an IF in the loop, and set Count ← 0 before the loop starts so the count begins at zero.
6IF Value > Max THEN Max ← Value — Finds the largest value: set Max to the first value, loop through the rest, and replace Max whenever a larger value is found. The minimum works the same way using < instead.
7Average ← Total / Count — An average is the total divided by the count. Work it out after the loop ends, and only when Count is not 0. Store it in a REAL variable.
8linear search — Checks each array element in order from the first, comparing it with the target, until a match is found or the end of the array is reached.
9bubble sort — A sort that makes repeated passes, comparing neighbouring items and swapping them using a Temp variable if they are in the wrong order, until a pass makes no swaps.
10trace table — A table with a column per variable and a row per step. Use it to test an algorithm such as total, maximum, search or bubble sort by following a short list of values by hand.