In this article we report on middle school students' understanding of concepts related to the second step of the statistical problem-solving process, study design: create a plan and collect data. Students participated in an open-ended statistics lesson involving nonexperimental study design. For this research we analyzed the students' discourse…

This paper reports the findings of the second year of a four-year empirical research project. Its aim is to modify 'step-by-step' instructions for practical activities in a way that may enable the development of experimental design skills among junior high school learners. Each school year pupils spend six lessons doing practical activities using…

Background/Context: Observational studies often employ regression discontinuity (RD) designs and multiple control-group designs to explore the causal quantities of interest. RD designs assess policy and program effectiveness by assigning subjects to treatment based on whether they exceed a pre-defined cutoff. RD designs are classified into two…

Astronomy education is essential for STEM education in primary schools, and integrating engineering design-based science education enhances student engagement and achievement in the field of space science. Integrating engineering design into science education is essential for students to excel in astronomy and to meet the requirements of…

Recently developed randomized-test procedures for two independent-samples single-case designs are presented and applied to a memory-strategy intervention study with eight underperforming students from low SES backgrounds. Research design aspects, data-analysis features, and various output measures are provided to demonstrate the potential utility…

Background/Context: Some observational studies involve multiple layers of treatment selection, specifically in the context of the extended time accommodation (ETA) for English language learners (ELLs). In ETA settings, the first selection occurs due to the eligibility rule, where students whose ELL English proficiency is below a certain threshold…

In paired experiments, participants are grouped into pairs with similar characteristics, and one observation from each pair is randomly assigned to treatment. The resulting treatment and control groups should be well-balanced; however, there may still be small chance imbalances. Building on work for completely randomized experiments, we propose a…

Minimum discriminant information adjustment (MDIA), an approach to weighting samples to conform to known population information, provides a generalization of raking and poststratification. In the case of simple random sampling with replacement with uniform sampling weights, large-sample properties are available for MDIA estimates of population…

Many research problems in social science involve multilevel phenomena. However, discussions about multilevel research designs are limited in the mixed methods (MM) literature. Building on early writings in the field, this methodological discussion advances a refined definition of a multilevel MM research design. The refinement emerges from a…

Background: A common critique of adventure education research methodology is the overreliance on pre-/post-study designs to measure change. Purpose: This paper compares and contrasts two methods of data analysis on the same adventure education data set to show how these distinct approaches provide starkly different results and interpretation.…

Background: Over the past 20 years, much has been written about the merits and limitations of matching methods, particularly propensity score matching (see, e.g., Stuart, 2010 for a review of matching approaches), and the myriad ways matching can be implemented to identify a comparison group that is similar to the treatment group on observable…

Findings from experimental studies have increasingly been used to inform policy in school settings. Thus far, the populations in many of these studies are typically defined in a cross-sectional context; namely, the populations are defined in the same academic year in which the study took place or the population is defined at a fixed time point.…

Despite great interest in the transformative mixed methods, an example of using vignettes in a multiphase mixed methods interventional study has been lacking. This study investigates the social justice problem of poverty in the context of financial education with Hong Kong early adolescent ethnic minority students. The discussion contributes to…

These are the appendices for the report "The Effects of an Academic Language Program on Student Reading Outcomes." This study investigated WordGen Elementary, a program designed to improve fourth- and fifth-grade students' ability to understand and communicate academic language and their general reading skill. The program provider…

This follow-up study presents a design-based research (DBR) setting implemented over a three-year project called 'eKidZ - Teach Your Parents Well' which uses research-based learning and follows the four phases of DBR. In an iterative cycle, 20 teenagers aged 14-16 took on the role of researchers and investigated intergenerational learning and the…