Greenfield School is building an online admissions form for parents. The form includes: - a Month of Birth box, which only accepts a whole number for the month the child was born - a Home Postcode box, which must always contain something before the form can be submitted - a Conf…

Answer: ((a)) Validation is an automated check, carried out by a program, that data is reasonable, sensible or allowable (for example, that it falls within a set range or matches a required format); it does not check that the data is actually correct. Verification checks that data has been co… ((b)) A range check, limiting the entry to whole numbers from 1 to 12. An entry of 13 falls outside this range (a year has only 12 months), so it would be rejected by the range check. ((c)) A presence check (also called a required-field check). It tests whether a field has been left blank, so that the form cannot be submitted until the Home Postcode box contains some data. ((d)) Double-entry verification. The system compares the characters typed into the two boxes; if they are not identical, this indicates a mistyped reference number, and the parent is asked to re-enter one or both values - though the check cannot tell which of the two entries, if eithe…. Part (a): Validation vs verification Validation is an automated check performed by a program on entered data to test whether it is reasonable, sensible or allowable. For example, checking that a value falls within an expected range, is in…

AS & A Level Computer Science 9618: Validation vs Verification Checks

Greenfield School is building an online admissions form for parents. The form includes:

a Month of Birth box, which only accepts a whole number for the month the child was born
a Home Postcode box, which must always contain something before the form can be submitted
a Confirm Reference Number box, which asks the parent to type their 6-digit School Reference Number a second time, after typing it once into an earlier box

(a) State one difference between data validation and data verification. [2]

(b) State the name of a suitable validation check for the Month of Birth box, and use it to explain whether an entry of 13 would be accepted by this check. [2]

(c) Name the validation check that would be used to make sure the Home Postcode box is never left empty when the form is submitted, and explain what this check tests for. [2]

(d) Name the verification method used by the Confirm Reference Number box, and describe how it would detect that a parent has mistyped their reference number into one of the two boxes. [2]

Part (a): Validation vs verification

Validation is an automated check performed by a program on entered data to test whether it is reasonable, sensible or allowable. For example, checking that a value falls within an expected range, is in the correct format, or has not been left blank. Validation can never confirm that data is actually correct, only that it is plausible.

Verification checks that data has been transferred or entered accurately, so that it matches its original source. This is usually done either by a person checking the data by eye against the original, or by typing the same data in twice (double entry) and having the system compare the two copies.

[2 marks]: [1] for correctly describing validation as an automated program check of reasonableness, [1] for correctly describing verification as a check that data has been accurately copied or entered, without conflating the two.

Part (b): Validating the Month of Birth box

A range check is appropriate here, since a month must be a whole number between 1 and 12 inclusive.

An entry of 13 is outside this allowed range, there is no 13th month, so the range check would reject it and the form would not accept the entry.

[2 marks]: [1] for naming a range check, [1] for correctly explaining that 13 is rejected because it falls outside the range 1 to 12.

Part (c): Validating the Home Postcode box

A presence check (required-field check) is used here. It simply tests whether the field contains any data at all when the form is submitted. It does not check the pattern or format of what has been typed, only that the box has not been left empty.

[2 marks]: [1] for naming a presence check, [1] for correctly explaining that it tests whether the field has been left blank.

Part (d): Verifying the Confirm Reference Number box

This is an example of double-entry verification. The parent types their reference number once, then types it again into a second box. The system compares the two entries character by character: if they match, the reference number is accepted as accurately entered; if they do not match, the mismatch reveals that at least one of the two entries was mistyped, and the parent is prompted to check and re-enter the number.

Note that this only checks that the two entries agree with each other. It cannot confirm that the reference number itself is genuinely correct, since an incorrect number typed identically both times would still pass.

[2 marks]: [1] for naming double-entry verification, [1] for correctly describing how comparing the two entries detects a mistyped number.

Final answers

(a) Validation is an automated program check that data is reasonable/allowable; verification checks that data has been accurately copied or entered, matching its source.
(b) Range check (1 to 12); 13 is rejected as it is outside this range.
(c) Presence check; tests whether the field has been left blank.
(d) Double-entry verification; comparing the two typed entries reveals a mismatch caused by a mistyped number.