On the Cover
Ally Shay Thomas · Educational Measurement Issues and Practice · 2018
It is a common practice to track test forms in equating chains across various administrations. The submitted plot aims to augment form information in an equating chain diagram to help inform and evaluate assessment and equating designs. In general, the plot displays a chronological sequence of forms that have been administered, and form information including 1) form name, 2) form difficulty, 3) administration time, 4) cumulative test-taker volume on the form, 5) problematic item information (i.e., DNS as “Do not score” item), 6) DNS item id, and 7) whether the form has been reused. The plot resembles a tree where each circle's location defines the average raw score for a particular form at a given administration. The line connections indicate the form sequence in the equating chains. The plot shows the spread of the average raw scores across the forms within each administration in relation to the scaling form, and over administrations which can help detect any consistent shift over time (e.g., forms getting easier). The plot can also inform the potential overuse of any form that has been reused and has a cumulative test-taker volume up to its most recent administration. In addition, the plot offers dynamic features to 1) show form information once the mouse is hovered over any circle, and 2) enable users to zoom in and pan the plot so that the form information can be scrutinized easily. If you are interested in learning more about this informative and detailed data visualization, contact the principal author Caiyan Zhang ([email protected]). We want to hear your feedback! Let us know what you think by emailing Ally Shay Thomas ([email protected]).