Podcast
Questions and Answers
What is the purpose of validation in data entry?
What is the purpose of validation in data entry?
The purpose of validation is to ensure that the data entered conforms to defined rules and is sensible.
Explain the difference between a range check and a limit check.
Explain the difference between a range check and a limit check.
A range check involves two boundaries (a lower and an upper limit), while a limit check has only a single boundary either as the highest or lowest possible value.
How does a presence check function in data validation?
How does a presence check function in data validation?
A presence check ensures that data has been entered; if not, an error message prompts the user to provide the required data.
What does a type check verify in data entry?
What does a type check verify in data entry?
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Why can valid data still be incorrect, and provide an example?
Why can valid data still be incorrect, and provide an example?
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Study Notes
Data Validation Techniques
- Validation ensures data is sensible and conforms to predefined rules before being accepted into a computer system.
- Each data type must adhere to specific rules; invalid data will trigger an error message.
Presence Check
- Ensures that required data has been entered.
- Accepts data if present; prompts for input if data is missing.
Range Check
- Validates that data falls within a defined numeric range.
- Limit check involves a single boundary, while range check has both lower and upper boundaries.
- Examples of comparison symbols:
-
greater than
-
= greater than or equal to
- < less than
- <= less than or equal to
-
- Data within boundaries is valid, but valid data may still be incorrect.
Type Check
- Ensures data is of the correct data type, such as:
- Age must be an integer.
- Grade must be text without numbers.
- Price must be numerical.
- Date of birth must be a valid date.
- Correct data type does not guarantee correctness; for example, future dates may be valid in format but incorrect in context.
Length Check
- Validates that data conforms to specified lengths or ranges.
- Examples:
- Passwords must be at least six characters.
- Grades must be one character long.
- Product codes range from four to six characters.
- Valid length does not ensure data correctness.
Format Check
- Ensures data conforms to a predefined pattern or format.
- Valid data meets the specified format, but may still be incorrect, like an improper email address.
Lookup Check
- Tests if input data exists within a defined list.
- Examples include predetermined values for gender (e.g., Male, Female) or grading systems (X for fail, P, M, D for pass, merit, distinction).
Consistency Check
- Compares two fields of data within a record to ensure consistency between them.
Check Digit
- A number or letter appended to an identification number used for validation.
- Generated by an algorithm, the check digit must match when inputting the identification number.
- Check digits provide redundancy and serve as an error detection mechanism.
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Description
Test your knowledge on data validation techniques, including presence checks, range checks, and type checks. Understand how these methods ensure data integrity before entering a computer system. This quiz is essential for anyone interested in data management and computer systems.
