Reading Intervention and Intelligence: A Study on Selection Bias and Testing Effects

Professor Fan C. Pants tested her class of 22 students on their reading ability, provided the 11 lowest scoring students with a reading improvement program, and - when the program ended - gave all students an intelligence test.

Which, if any, of the following apply to Prof. Pants's study? Mark all that apply.

'Statistical regression effects' 'Reversal design' 'Instrumentation' 'Cross-sectional' 'Selection biases' 'Testing effects' 'External validity' 'Discontinuity effects'

'Statistical regression effects' 'Instrumentation' 'Selection biases' 'Testing effects' 'External validity'