A researcher wanted to test the psychometric properties of a new intelligence test for children. She administered the test twice, two months apart, to children in a fourth-grade classroom. On the second administration, she noticed that the children who performed well were not the same children who performed well on the first administration and that there appeared to be no relationship between student performance on the first and second administration of the test. Based on this scenario, the psychological construct missing from this intelligence test is.

test-retest reliability

Explanation: In other to validate the outcome of a test or an experiment, researchers may often repeat a particular test more than once, in other to ensure that conclusion or inference drawn from the first or initial test aren't wrong. This is known as test-retest reliability. Test retest reliability involves, that the test retaken is performed under the the same condition as the first. This is to ensure that observed differences aren't due to changes in experimental conditions. In the context above, the test was conducted twice using the same participant and condition, in other to establish the validity or reliability of the first or initial test. Since the outcome of the first and second test do not conform, the intelligence test lacks test retest reliability.