Course: Communication Research Methods. Objectives: This activity provides students with an experiential introduction to measurement theory and the methods for assessing measurement reliability. First, multiple measurements of a person's height are interpreted according to classical test theory. Second, the measurement of human height is used as…

As an alternative to Cronbach's [alpha] for estimating scale reliability, McDonald's [omega] has attracted increased attention within the methodological community for its less stringent measurement assumptions. Notwithstanding, [omega] is still seldom used by practitioners, likely due to its unavailability in popular software packages (e.g., SPSS)…

Spearman's correction for attenuation (measurement error) corrects a correlation coefficient for measurement errors in either-or-both of two variables, and follows from the assumptions of classical test theory. Spearman's equation removes all measurement error from a correlation coefficient which translates into "increasing the reliability of…

Multilevel modeling (MLM) is frequently used to detect cluster-level group differences in cluster randomized trial and observational studies. Group differences on the outcomes (posttest scores) are detected by controlling for the covariate (pretest scores) as a proxy variable for unobserved factors that predict future attributes. The pretest and…

Interpreting and creating graphs plays a critical role in scientific practice. The K-12 Next Generation Science Standards call for students to use graphs for scientific modeling, reasoning, and communication. To measure progress on this dimension, we need valid and reliable measures of graph understanding in science. In this research, we designed…