Test Data | Computer for GCSE/IGCSE - Year 11 PDF Download

Suggesting and applying suitable test data

• Testing Sub-Systems Before System Deployment: Before a system is put into operation, each sub-system should undergo tests to verify proper functionality and seamless interaction with other sub-systems. 
• Program Testing Procedures: Programs are evaluated by running them on a computing device. Additionally, pseudocode and flowcharts necessitate manual dry runs. Both processes demand carefully selected and varied test data sets. The resulting outputs are then cross-referenced with the anticipated results to validate the algorithm's intended operation. 

Various Types of Test Data

Normal

• Standard test data refers to the data that a system is anticipated to manage routinely, being valid for the algorithm and yielding anticipated outcomes.
• Illustrations encompass entering individuals' personal information like names, addresses, phone numbers, and student grades represented as percentages.
• Test data for student percentage grades might include figures like 34, 41, 56, 78, 12, and 92.

Abnormal

• Termed as erroneous data, abnormal data refers to data anticipated to result in failure and should be declined by the system. It serves to demonstrate the system's accuracy by rejecting incorrect data.
• Instances of abnormal data include inputting numerical values instead of a person's name or entering textual content instead of numerical values.
• Examples of abnormal data for student percentage grades might include entries like "abc," "7&n," "Harry," "£300," and "<!%."

Extreme

• Extreme test data represents the maximum and minimum values within the acceptable range of normal data that the system acknowledges.
• Illustrations encompass percentage values like 0 and 100, days in April ranging from 1 to 30, or the character count range for passwords.
• For a password range of 8 to 20 characters, testing would include passwords of both 8 and 20 characters in length.

Boundary

• Boundary test data is akin to extreme data but also includes testing values immediately adjacent to the maximum and minimum values.
• It involves testing the largest and smallest acceptable values, as well as the largest and smallest unacceptable values.
• For instance, in a percentage boundary test, values tested would include 0 and -1 (for 0), as well as 100 and 101 (for 100). Similarly, for days in April, testing would involve 1 and 0 (for day 1) and 30 and 31 (for day 30). For passwords with an 8-20 character range, testing would include an 8 and 7 character password, as well as a 20 and 21 character password.