In biology, Tsui and Treagust (2009) developed a two-tier instrument for students' understanding about genetics.
The "Tiering Tool" instrument asked the MHFs to assess the extent to which sites were building the capacity to make sustainable changes to the practice, and actually testing and implementing changes.
Two-tier instruments have also been developed that focus less explicitly on scientific content but on other outcomes of interest in science education.
Assessment developers who create two-tier instruments may wish to report not only information on the overall performance of students, but also information on how the items may have varying difficulty according to content and to tier.
Implications: This study indicates that the workbook may be a useful first-tier assessment instrument and educational tool for the older driver.
Evaluating secondary students' scientific reasoning in genetics using a two-tier diagnostic instrument.
[Abstract available: www.informaworld.com/smpp/content∼db=all∼content=a912566870] Tsui and Treagust document the development and implementation of a two-tier multiple-choice instrument for diagnosing high school students' knowledge about genetics (tier 1) as well as their explanations of that knowledge ("reasoning," tier 2).
One approach is a return to an assessment tool format that has been developed previously by science education researchers, namely, the "two-tier" multiple-choice instrument (for examples, see Tamir, 1971; Treagust, 1988).
Computer-assisted formative assessments with multiple-tier items are a valid instrument for diagnosing students' conceptual understanding in learning domains with well-structured declarative knowledge (e.g. science education).
However, in the case of the paired items on this instrument, the first-tier "What happens?" item is often quite easy, and provides the necessary context for the more difficult second-tier "Why does this happen?" item.
Employing a Rasch measurement model on TTMC items, the researchers explored whether items were distinguishable according to different traits, different content sub-topics within the instrument, or both content and tier.
