Topics / Programming / Testing and Test Data

# Testing and Test Data

It is important to test algorithms to check how they perform under a range of conditions.

This includes testing any validation you have created to ensure it performs as expected.

When creating a testing plan, the test data that you use shouldn’t be random values, but rather values that fulfil the following test criteria.

## Normal data

Normal data is test data that is typical (expected) and should be accepted by the system.

## Extreme data

Extreme data is test data at the upper or lower limits of expectations that should be accepted by the system.

## Boundary data

A pair of values at each end of a range:

• The data at the upper or lower limits of expectations that should be accepted
• The immediate values before or beyond the limits of expectations that should be rejected

## Abnormal data (erroneous data)

Abnormal data is test data that falls outside of what is acceptable and should be rejected by the system.

## Example of normal data, extreme data, boundary data and abnormal data:

A system has validation to ensure that only integers between 1 and 10 are entered as an input.

The test data for this could be:

Normal data: 5
Boundary data: 1, 10 (to be accepted); 0, 11 (to be rejected)
Extreme data: 1, 10
Abnormal data (erroneous data): Thirteen, 5.7, 14

Topics / Programming / Testing and Test Data