Reliability assesses the extent to which variations in test scores reflect true differences in ability between people (on the construct being measured) rather than random errors in measurement.

The Abstract Thinking Assessment has a reliability coefficient of 0.71. The measure of reliability for this assessment was computed through the split-half method. Here, the assessment is split into two parts and both parts are given to one sample at the same time. The most commonly used method to split the test into two is using the odd-even strategy. The scores from both parts of the test are correlated.

Split-half testing was chosen as it is the most commonly used reliability measure for multiple choice tests. Additionally, it allowed the seamless computation of reliability through one administration of the assessment to the appropriate sample. It overcomes problems associated with multiple test administration, sample accessibility, and the effect of learning and memory.

Validity assesses the degree to which a scale measures the construct that it claims to measure. The Abstract Thinking Assessment has a validity coefficient of 0.37, determined via concurrent validity. Concurrent validity measures how well a new test compares to a well-established test that assesses the same construct.

A sample was administered the Abstract Thinking Assessment and Raven's Advanced Progressive Matrices (APM) to measure the concurrent validity of the Jombay assessment. The APM is a well-established measure of traits associated with fluid intelligence and higher cognition. Concurrent validity has been found to be a robust method of assessing validity and overcomes problems associated with limited access to future outcomes, which plagues other validity methods.