calculateAdaptivityMeasures is a function for
calculating commonly used adaptivity measures.
calculateAdaptivityMeasures(x)calculateAdaptivityMeasures returns a named list:
corr the correlation between final theta estimates and average test locations.
ratio the ratio of (1) standard deviation of average test locations, versus (2) standard deviation of final theta estimates.
PRV the proportion of variance reduced, from (1) the variance of item locations of all items in the pool, by (2) the average of test location variances.
info (1) average information of a test at final theta estimate, relative to (2) best average obtainable from item pool using same test length, adjusting for (3) average information from item pool using random selection.
an output_Shadow_all object.