Washback effect refers to the impact of testing on curriculum design, teaching practices, and learning behaviors.
[1] The influences of testing can be found in the choices of learners and teachers: teachers may teach directly for specific test preparation, or learners might focus on specific aspects of language learning found in assessments.
Tests were made to be economical, using multiple-choice questions and focusing on psychometric validity, but perhaps not measuring more complex abilities.
Significant variability has been noted in the ways that teachers respond to test changes and classroom assessments.
Effects may be superficial, indirect, and unpredictable due to individual differences in the way that learning is mediated by teachers, textbook writers, and publishers.