No abstract

This study aimed to investigate to what extent the use of hands-on science activities influences on students" academic achievement in science. Review of literature revealed several research studies focusing upon such aim and thus, a meta-analysis of these researches was carried out to obtain an overall effect size estimate of hands-on science activities on science achievement. Of the available studies, 15 with multiple outcomes satisfied the pre-determined inclusion criteria. In addition to the estimation of overall effect size using fixed-and random-effects models, subgroup analyses were also run through a mixed-effect model to determine whether heterogeneity in effect size estimates is due to the influence of moderator variables. Results showed that the estimated effect size was statistically significant (Z=8.57, p < .01). The magnitude of the overall effect size estimate indicated that the hands-on activities had a very large impact on students" science achievement (Hedge`s g = 1.55, 95% CI= [1.20-1.91]). The effect size estimates for each moderator variable was also statistically significant at alpha level of .01, but no difference was found within sub-categories of moderator variables.

The aim of this study is to compare the performances of Identity, Nominal Weights Mean (NMW), and Circle-Arc (CA) equating methods under the Non-Equivalent Groups Anchor-Test (NEAT) design. Synthetic equating functions (SFs) of the NWM and CA (NWS and CAS) were also created using an equal weighting system (w = 0.5). Different sizes of small examinee samples (n = 10, 20, 50, 100) were used to equate new test forms to base test forms. Chained Equipercentile (CE) with bivariate log-linear presmoothing was used as population criterion equating function to compare the performances of the equating methods. Overall, the identity (ID) equating was the most favorable, but the NWS method produced less equating error than the ID and Tucker Linear (TL) equating methods under specific simulation conditions. The use of the SF of the NWM method can be used in practice to equate the test forms with samples less than 25 examinees. In future studies, the SFs of other existing equating methods should be tested to determine the best performing equating method(s) for small sample equating.