Test-Retest Reliability of Individual Student Acquisition and Retention Rates as Measured by Instructional Assessment
Authors:   ,   Andrews University, Burns Matthew 
Published: May 2023

Statement of the problem. Research on Instructional Assessment is in its infancy. To date, no studies regarding its psychometric properties have been published, but the need for using technically sound assessment methods is prominent in education. Therefore, demonstrated technical adequacy is crucial. The lack of psychometric data for Instructional Assessment is especially noteworthy since it is one of the few educational assessment techniques that includes assessment of performance and cognitive learning theory, both of which have been linked to improved student achievement. Method. Ninety-six students from Grades 1, 3, and 5 were individually taught a series ofwords from the Esperanto International Language using the Incremental Rehearsal technique until they reached a defined level of interference. The number of words learned before interference occurred was recorded as the rate of acquisition, and the students were tested for retention 1 to 3 days later. After an interval of 14 days, the same students were again individually taught different words from the Esperanto list using the Incremental Rehearsal technique until interference occurred, and they were again tested for retention 1 to 3 days later. The acquisition rates, rates of retention expressed in terms of the number of words remembered, and rates of retention expressed as a percentage of the acquisition rate were all correlated using the Pearson r . The two different approaches to retention rates were compared using a t -test. Results. The results of the study listed test-retest coefficients for the rates of acquisition that ranged from .756 to .931. The coefficients for the rates of retention described as the number of words retained fell between .679 and .919, while the reliability coefficients for the retention rates listed as a percentage of the acquisition rate fell between .342 and .848. The test-retest reliability of rates of acquisition and retention fell above a standard minimum level necessary to base educational decision on the data, and revealed significant correlations ( p < .01). However, this was true only for Grades 3 and 5, not Grade 1, and was not true for rates of retention listed as a percentage of the acquisition rate. The comparison between correlations for retention rates as a number of words retained and asa percentage of words acquired revealed significantly higher ( p < .01) correlations for the former over the latter. Conclusions. Instructional Assessment using the Incremental Rehearsal model is a reliable method of measuring an individual student's rate of acquisition for Grades 3 and 5. It is also a reliable approach for Grades 3 and 5 to measure rates of retention if they are expressed asthe number of words retained. In general, expressing the rate of retention as the number of words retained is a more reliable method than expressing it as a percentage of the acquisition rate. The practical applications for effective instruction are discussed in terms ofthe amount of new information that can be presented to individual learners to increase student achievement.