Model Development in Processing Local Item Dependency (LID) in Testlet-composed Test Analysis

A new finite element model (FEM) reduction method is presented for use in the generation of Test-Analysis-Models (TAM) in test-analysis correlation. The method addresses the concern that some current TAM methodologies, specifically the Modal TAM, are overly sensitive to differences between test mode shapes and analysis mode shapes. This sensitivity can result in large off-diagonal terms within the orthogonality and cross-orthogonality matrices used for test-analysis mode shape correlation. It has been hypothesized that the sensitivity is due to the Modal TAM’s poor representation of residual mode shapes and frequencies which are modes that are not targeted for identification. In many cases it has been observed that the less accurate static TAM often gives better off-diagonal correlation results. A new Hybrid TAM methodology is developed to combine the exact representation of the FEM target modes from the Modal TAM with the more accurate static TAM representation of the residual modes. The superior residual dynamics representation of the Hybrid TAM is demonstrated for both a simple spacecraft and a much more detailed representation of a Large Space Structure. Simulated test-analysis correlation results are presented for both examples where test mode shapes are represented by FEM target modes with noise modeled as a random linear combination of all FEM modes. Analysis indicates that the Hybrid TAM’s improved residual representation results in reduced sensitivity of the test-analysis correlation to model error.

Download Full-text

Development of Pop-Up Book Learning Media to Improve Understanding of Teaching

Middle European Scientific Bulletin ◽

10.47494/mesb.2021.13.625 ◽

2021 ◽

Vol 13 ◽

Author(s):

Dwi Lestariningsih ◽

Pandi Rais ◽

Nurdyansyah, Nahdliyah Mutala'liah

Keyword(s):

Model Development ◽

T Test ◽

P Value ◽

Test Statistic ◽

Test Analysis ◽

Mean Values ◽

Significance Level ◽

Content Expert ◽

Group Trial ◽

Expert Validation

Research uses the development of Borg and Gall model development. The product produced in the development of grade 4 pop-up books in elementary schools in Sidoarjo, Indonesia. The results of the development of learning media by the criteria with the results of content expert validation have a 100% validity percentage. Validation from design experts has a 90% validity percentage, Validation results from linguists have a 100% validity percentage, individual results are found 100%, small group trial results are 97.14%, large group trial results are 98.21%. The results of the t-test analysis using SPSS 16 with a significance level of 0.05 indicate the p-value of the t-test statistic is 0.00, which means (<0.05), it can be concluded that there is a significant significance in the pretest mean values and posttest. This shows the pop-up book learning media developed effectively in increasing students' understanding of Class 4 in Sidoarjo, Indonesia.

Download Full-text