The present article considers a fundamental question in evaluation research: "By how much do program effects vary across sites?" The article first presents a theoretical model of cross-site impact variation and a related estimation model with a random treatment coefficient and fixed site-specific intercepts. This approach eliminates…

In learning systems and environment research, intelligent tutoring and personalisation are considered the two most important factors. An Intelligent Tutoring System can serve as an effective tool to improve problem-solving skills by simulating a human tutor's actions in implementing one-to-one adaptive and personalised teaching. Thus, in this…

We examined whether 2 types of interpolated tasks (i.e., retrieval-practice via free recall or guessing a missing critical item) improved final recognition for related and unrelated word lists relative to restudying or completing a filler task. Both retrieval-practice and guessing tasks improved correct recognition relative to restudy and filler…

Weak performance in short-term memory (STM) in children with cochlear implants (CI) may have an impact on vocabulary development. Vocabulary, phonological STM (non-word repetition), phonological/verbal STM (digit span) and rapid naming measures were administered to 15 Greek-speaking children with CI (ages 4;6-8;6) and to chronological age (CA) and…

Researchers may have multiple motivations for combining disparate pieces of evidence in a meta-analysis, such as generalizing experimental results or increasing the power to detect an effect that a single study is not able to detect. However, while in meta-analysis, the main question may be simple, the structure of evidence available to answer it…

In a world where environmental degradation is taking on alarming levels, understanding, and acting to minimize, the individual environmental impact is an important goal for many science educators. In this study, a green chemistry curriculum--combining chemistry experiments with everyday, environmentally friendly substances with a student-centered…

Propensity score applications are often used to evaluate educational program impact. However, various options are available to estimate both propensity scores and construct comparison groups. This study used a student achievement dataset with commonly available covariates to compare different propensity scoring estimation methods (logistic…

As an initial effort to reorient the current Malaysian chemistry curriculum, "green chemistry" was developed. In this study for the purpose of investigating the effectiveness of the green chemistry curriculum on secondary school students' understanding of chemistry concepts a quasi-experimental design was used. One-group pretest posttest…

Errors in detecting randomness are often explained in terms of biases and misconceptions. We propose and provide evidence for an account that characterizes the contribution of the inherent statistical difficulty of the task. Our account is based on a Bayesian statistical analysis, focusing on the fact that a random process is a special case of…