Use Bayesian estimation with a weak prior on the between slope to increase maximum power or reduce the required budget when resources are very limited¶

Strategy · All strategies
Evidence · 3 claims (3 for) · 1 study (1 theoretical), q2 · 0 of 1 report an effect size · 3 claims rest on one study

Description¶

The article's forward-looking recommendation is that Bayesian estimation can complement optimal design in classroom climate studies. The prior distribution "can be specified in such a way that the variability of the results for the between slope will be small": with a weak prior the variability becomes a factor times the variability in Eq. 5, so "the maximum level of power will be increased given a fixed budget, and the minimum budget required to achieve a prespecified level of power will be reduced." The authors flag this as particularly attractive when a study's budget is very limited and call for further research on its benefits.

Design Implications¶

Context¶

Requirements¶

• Specification of a weak prior for the between slope in a Bayesian estimator applied to the multilevel latent covariate model

Constraints¶

• The article presents this as a promising direction based on prior work (Zitzmann et al., 2015, 2021), not as a procedure demonstrated within this article

Target Learners¶

• Educational researchers conducting classroom climate studies on limited budgets

Target Learning Goals¶

• Maximizing statistical power or minimizing study cost when relating classroom climate to student outcomes

Claims¶

• The variability of the between slope estimate in the multilevel latent covariate model decreases with more classes and students, with higher ICC(1) of the ratings and larger slopes, but increases with higher ICC(1) of the outcome [+W]
• Under a fixed budget, a higher ICC(1) of the outcome variable shifts the optimal design toward more classes and fewer students per class and reduces maximum power [+W]
• A higher ICC(1) of students' ratings and a larger standardized between slope increase power, with opposite effects on the optimal split between classes and students per class [+W]

Related Strategies¶

Examples¶

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Key Sources¶

• Steffen Zitzmann, Wolfgang Wagner, Martin Hecht, Christoph Helm, Christian Fischer, Lisa Bardach, Richard Göllner. (2021). How Many Classes and Students Should Ideally be Sampled When Assessing the Role of Classroom Climate via Student Ratings on a Limited Budget? An Optimal Design Perspective. Educational Psychology Review (2022) 34:511–536. https://doi.org/10.1007/s10648-021-09635-4