| Tag | Value |
|---|---|
| file | Reliability_eur-reliability-113-en_eur-reliability-113-en |
| name | eur-reliability-113-en |
| section | Reliability/Analysis/Cronbach's alpha |
| type | string |
| solution | "" |
| Type | Conceptual |
| Program | |
| Language | English |
| Level | Statistical Reasoning |
The “Three Minutes Test” (TMT) is a test to assess technical reading level. Children have to accurately read as many words as possible during three minutes. A teacher from grade 5 wants to use the test, which was constructed for children in grade 2, to assess the reading skills of her grade 5 children. Cronbach’s alpha based on the grade 2 population is .88 and the standard deviation of the test scores in grade 2 is 3.
Explain why the TMT will probably be less reliably for the children in grade 5.
The TMT will probably be less reliably for the children in grade 5 because the variation in true scores is expected to be smaller. Since it is assumed from classical test theory that the error variance is equal for children in grade 2 and grade 4, the reliability will be lower in a population with less true score variance.