scholarly journals Using Dr. Scratch as a Formative Feedback Tool to Assess Computational Thinking

2022 ◽  
pp. 550-572
Author(s):  
Peter Rich ◽  
Samuel Frank Browning
Keyword(s):  
Maximum Likelihood ◽  
Linear Regression ◽  
Propensity Score ◽  
Multiple Linear Regression ◽  
Treatment Effect ◽  
Computational Thinking ◽  
Formative Feedback ◽  
Treatment Groups ◽  
Automatic Feedback ◽  
Maximum Likelihood Technique

This study investigated if using Dr. Scratch as a formative feedback tool would accelerate students' Computational Thinking (CT). Forty-one 4th-6th grade students participated in a 1-hour/week Scratch workshop for nine weeks. We measured pre- and posttest results of the computational thinking test (CTt) between control (n = 18) and treatment groups (n = 23) using three methods: propensity score matching (treatment = .575; control = .607; p = .696), information maximum likelihood technique (treatment effect = -.09; p = .006), and multiple linear regression. Both groups demonstrated significantly increased posttest scores over their pretest (treatment = +8.31%; control = +5.43%), showing that learning to code can increase computational thinking over a 2-month period. In this chapter, we discuss the implications of using Dr. Scratch as a formative feedback tool the possibilities of further research on the use of automatic feedback tools in teaching elementary computational thinking.

scholarly journals Using Dr. Scratch as a Formative Feedback Tool to Assess Computational Thinking

2020 ◽  
pp. 220-242
Author(s):  
Peter Rich ◽  
Samuel Frank Browning
Keyword(s):  
Maximum Likelihood ◽  
Linear Regression ◽  
Propensity Score ◽  
Multiple Linear Regression ◽  
Treatment Effect ◽  
Computational Thinking ◽  
Formative Feedback ◽  
Treatment Groups ◽  
Automatic Feedback ◽  
Maximum Likelihood Technique

This study investigated if using Dr. Scratch as a formative feedback tool would accelerate students' Computational Thinking (CT). Forty-one 4th-6th grade students participated in a 1-hour/week Scratch workshop for nine weeks. We measured pre- and posttest results of the computational thinking test (CTt) between control (n = 18) and treatment groups (n = 23) using three methods: propensity score matching (treatment = .575; control = .607; p = .696), information maximum likelihood technique (treatment effect = -.09; p = .006), and multiple linear regression. Both groups demonstrated significantly increased posttest scores over their pretest (treatment = +8.31%; control = +5.43%), showing that learning to code can increase computational thinking over a 2-month period. In this chapter, we discuss the implications of using Dr. Scratch as a formative feedback tool the possibilities of further research on the use of automatic feedback tools in teaching elementary computational thinking.

scholarly journals Inference in Multiple Linear Regression Model with Generalized Secant Hyperbolic Distribution Errors

2021 ◽  
Vol 17 (33) ◽  
pp. 45-70
Author(s):  
Álvaro Alexander Burbano Moreno ◽  
Oscar Orlando Melo-Martinez ◽  
M Qamarul Islam
Keyword(s):  
Maximum Likelihood ◽  
Linear Regression ◽  
Regression Model ◽  
Multiple Linear Regression ◽  
Linear Regression Model ◽  
Multiple Linear Regression Model ◽  
Least Square ◽  
Model Parameters ◽  
Modified Maximum Likelihood ◽  
Test Of Hypothesis

We study multiple linear regression model under non-normally distributed random error by considering the family of generalized secant hyperbolic distributions. We derive the estimators of model parameters by using modified maximum likelihood methodology and explore the properties of the modified maximum likelihood estimators so obtained. We show that the proposed estimators are more efficient and robust than the commonly used least square estimators. We also develop the relevant test of hypothesis procedures and compared the performance of such tests vis-a-vis the classical tests that are based upon the least square approach.

scholarly journals Evaluating Glaucoma Treatment Effect on Intraocular Pressure Reduction Using Propensity Score Weighted Regression

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mengfei Wu ◽  
Mengling Liu ◽  
Joel S. Schuman ◽  
Yuyan Wang ◽  
Katie A. Lucy ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Propensity Score ◽  
Selection Bias ◽  
Treatment Effect ◽  
Laser Surgery ◽  
Observational Studies ◽  
Combination Therapies ◽  
Treatment Groups ◽  
Valid Assessment ◽  
Important Evidence

Abstract Observational studies in glaucoma patients can provide important evidence on treatment effects, especially for combination therapies which are often used in reality. But the success relies on the reduction of selection bias through methods such as propensity score (PS) weighting. The objective of this study was to assess the effects of five glaucoma treatments (medication, laser, non-laser surgery (NLS), laser + medication, and NLS + medication) on 1-year intraocular pressure (IOP) change. Data were collected from 90 glaucoma subjects who underwent a single laser, or NLS intervention, and/or took the same medication for at least 6 months, and had IOP measures before the treatment and 12-months after. Baseline IOP was significantly different across groups (p = 0.007) and this unbalance was successfully corrected by the PS weighting (p = 0.81). All groups showed statistically significant PS-weighted IOP reductions, with the largest reduction in NLS group (−6.78 mmHg). Baseline IOP significantly interacted with treatments (p = 0.03), and at high baseline IOP medication was less effective than other treatments. Our findings showed that the 1-year IOP reduction differed across treatment groups and was dependent on baseline IOP. The use of PS-weighted methods reduced treatment selection bias at baseline and allowed valid assessment of the treatment effect in an observational study.

scholarly journals Trophectoderm biopsy of blastocysts for a preimplantation genetic test does not affect serum β-hCG levels in early pregnancy: a study using propensity score matching

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yixuan Wu ◽  
Ying Ying ◽  
Mingzhu Cao ◽  
Jianqiao Liu ◽  
Haiying Liu
Keyword(s):  
Linear Regression ◽  
Propensity Score ◽  
Multiple Linear Regression ◽  
Propensity Score Matching ◽  
Live Birth ◽  
Genetic Test ◽  
Clinical Pregnancy ◽  
Control Group ◽  
Trophectoderm Biopsy ◽  
Β Hcg

Abstract Background Although preimplantation genetic test (PGT) has been used worldwide, few studies investigated the effect of trophectoderm biopsy of blastocysts on early embryo development. This study aimed to investigate whether trophectoderm (TE) biopsy of blastocysts for a PGT affected serum β-human chorionic gonadotropin (hCG) levels 14 days after transfer. Methods This was a retrospective cohort study conducted at the Third Affiliated Hospital of Guangzhou Medical University. The study population comprised pregnant women undergoing the transfer of single vitrified-warmed blastocysts after PGT between January 1, 2018, and July 30, 2020. The control group had non-PGT cycles with other inclusion criteria identical to those for the study group. Propensity score matching was used to screen a group of patients so that the baseline characteristics were similar between the two groups. Serum β-hCG levels were compared between the PGT and non-PGT cycles. Multiple linear regression was used to analyze the influence of PGT on serum β-hCG levels, while receiver operating characteristic curves (ROC curves) were plotted to predict pregnancy outcomes using serum β-hCG levels. Results Serum β-hCG levels were comparable between the PGT and non-PGT patients: live birth: 2503 ± 1702 mIU/mL vs 2266 ± 1289 mIU/mL (P = 0.219); clinical pregnancy: 2261 ± 1564 mIU/mL vs 2148 ± 1348 mIU/mL (P = 0.461); and ongoing pregnancy: 2412 ± 1589 mIU/mL vs 2278 ± 1308 mIU/mL (P = 0.422). Multiple linear regression analysis indicated no impact of PGT on the serum β-hCG level (standardized coefficient = − 0.001, P = 0.989). For clinical pregnancy, the cutoff value was 482 mIU/mL and 302 mIU/mL for PGT and non-PGT patients, respectively. The threshold to predict live birth was 1345 mIU/mL and 1621 mIU/mL in the PGT and non-PGT cycles, respectively. Conclusion Trophectoderm biopsy of blastocysts for PGT did not affect the serum β-hCG level 14 days after transfer.

scholarly journals Trophectoderm Biopsy of Blastocysts for a Preimplantation Genetic Test does not Affect Serum β-hCG Levels in Early Pregnancy: A Study using Propensity Score Matching

2020 ◽  
Author(s):  
Yixuan Wu ◽  
Ying Ying ◽  
Jianqiao Liu ◽  
Haiying Liu
Keyword(s):  
Linear Regression ◽  
Propensity Score ◽  
Multiple Linear Regression ◽  
Propensity Score Matching ◽  
Live Birth ◽  
Genetic Test ◽  
Clinical Pregnancy ◽  
Control Group ◽  
Trophectoderm Biopsy ◽  
Β Hcg

Abstract Background: Although preimplantation genetic test (PGT) has been used worldwide, few studies investigated the effect of trophectoderm biopsy of the blastocysts on early embryo development. This study aimed to investigate whether trophectoderm (TE) biopsy of blastocysts for a PGT affected serum β-human chorionic gonadotropin (hCG) levels 14 days after transfer.Methods: This was a retrospective cohort study conducted at the Third Affiliated Hospital of Guangzhou Medical University. The study population comprised pregnant women who underwent the transfer of single vitrified-warmed blastocysts after PGT between January 1, 2018, and July 30, 2020. The control group had non-PGT cycles with other inclusion criteria identical to those for the study group. Propensity score matching was used to screen a group of patients so that the baseline characteristics were similar between the two groups. Serum β-hCG levels were compared between the PGT and non-PGT cycles. Multiple linear regression was applied to analyze the influence of PGT on serum β-hCG levels, while receiver operating characteristic curves (ROC curves) were plotted to predict pregnancy outcomes using serum β-hCG levels. Results: Serum β-hCG levels were comparable between the PGT and non-PGT patients: live birth: 2478 ± 1675 mIU/mL vs 2303 ± 1300 mIU/mL (P = 0.361); clinical pregnancy: 2244 ± 1537 mIU/mL vs 2270 ± 1387 mIU/mL (P = 0.634); and ongoing pregnancy: 2391 ± 1600 mIU/mL vs 2360 ± 1372 mIU/mL (P = 0.852) respectively. Multiple linear regression analysis indicated no impact of PGT on the serum β-hCG level (standardized coefficients = –0.016, P = 0.756). For clinical pregnancy, the cutoff value was 482 mIU/mL and 277 mIU/mL for PGT and non-PGT patients, respectively. The threshold to predict live birth was 1345 mIU/mL and 1113 mIU/mL in the PGT and non-PGT cycles, respectively.Conclusion: Trophectoderm biopsy of blastocysts for PGT did not affect the serum β-hCG level 14 days after transfer.

scholarly journals Inference in Multiple Linear Regression Model with Generalized Secant Hyperbolic Distribution Errors

2021 ◽  
Vol 17 (33) ◽  
pp. 45-70
Author(s):  
Álvaro Alexander Burbano Moreno ◽  
Oscar Orlando Melo-Martinez ◽  
Q Qamarul Islam
Keyword(s):  
Maximum Likelihood ◽  
Linear Regression ◽  
Regression Model ◽  
Multiple Linear Regression ◽  
Linear Regression Model ◽  
Multiple Linear Regression Model ◽  
Least Square ◽  
Model Parameters ◽  
Modified Maximum Likelihood ◽  
Test Of Hypothesis

We study multiple linear regression model under non-normally distributed random error by considering the family of generalized secant hyperbolic distributions. We derive the estimators of model parameters by using modified maximum likelihood methodology and explore the properties of the modified maximum likelihood estimators so obtained. We show that the proposed estimators are more efficient and robust than the commonly used least square estimators. We also develop the relevant test of hypothesis procedures and compared the performance of such tests vis-a-vis the classical tests that are based upon the least square approach.

scholarly journals Collateral status and tissue outcome after intra-arterial therapy for patients with acute ischemic stroke

2016 ◽  
Vol 37 (11) ◽  
pp. 3589-3598 ◽  
Author(s):  
Anna MM Boers ◽  
Ivo GH Jansen ◽  
Olvert A Berkhemer ◽  
Albert J Yoo ◽  
Hester F Lingsma ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Linear Regression ◽  
Acute Ischemic Stroke ◽  
Brain Tissue ◽  
Treatment Effect ◽  
Significant Interaction ◽  
Standard Care ◽  
Treatment Groups ◽  
Interaction Terms ◽  
Grade 3

Intra-arterial therapy (IAT) for ischemic stroke aims to save brain tissue. Collaterals are thought to contribute to prolonged penumbra sustenance. In this study, we investigate the effect of collateral status on brain tissue salvage with IAT. In 500 patients randomized between IAT and standard care, collateral status was graded from 0 (absent) to 3 (good). Final infarct volumes (FIV) were calculated on post-treatment CT. FIVs were compared between treatment groups per collateral grade. Multivariable linear regression with interaction terms was performed to study whether collaterals modified IAT effect on FIV. Four-hundred-forty-nine patients were included in the analysis. Median FIV for the IAT group was significantly lower with 54.5 mL (95% IQR: 21.8–145.0) than for the controls with 81.8 mL (95% IQR: 40.0–154.0) ( p = 0.020). Treatment effect differed across collateral grades, although there was no significant interaction (unadjusted p = 0.054; adjusted p = 0.105). For grade 3, IAT resulted in a FIV reduction of 30.1 mL ( p = 0.024). For grade 2 and 1, this difference was, respectively, 28.4 mL ( p = 0.028) and 28.4 mL ( p = 0.29). For grade 0, this was 88.6 mL ( p = 0.28) in favour of controls. IAT saves substantially more brain tissue as compared to standard care. We observed a trend of increasing effect of IAT with higher collateral grades.

scholarly journals Effect of Caesarean Section on Neonatal Health in Bangladesh after Controlling Selection Bias: Propensity Score Based Analysis

2021 ◽  
Vol 69 (1) ◽  
pp. 23-29
Author(s):  
Md Mahmudur Rahman ◽  
Sabina Sharmin ◽  
Taslim Sazzad Mallick
Keyword(s):  
Caesarean Section ◽  
Propensity Score ◽  
Neonatal Mortality ◽  
Treatment Effect ◽  
Early Initiation ◽  
Treatment Groups ◽  
Early Neonatal Mortality ◽  
Early Initiation Of Breastfeeding ◽  
Weighting Methods ◽  
Initiation Of Breastfeeding

The paper examines the effect of caesarean section (C-section) on early neonatal mortality, neonatal mortality, and early initiation of breastfeeding using Bangladesh Demographic and Health Survey (BDHS), 2014 data. Propensity score matching and weighting methods were used to estimate unbiased estimate of treatment effect. The study demonstrates how conclusion about treatment effect varies with and without having balance in the treatment groups. Standard analysis, without caring about balance, reveals that C-section has no significant impact on early neonatal mortality and neonatal mortality. After applying propensity score adjusted methods, balance was achieved in the treatment groups and it was found that C-section has significant effect on early neonatal mortality and neonatal mortality. However, there was no difference between standard and PS adjusted methods in estimating the effect of C-section on early initiation of breastfeeding. It is concluded that children who were delivered by C-section have significantly lower odds of early neonatal mortality, neonatal mortality, and early initiation of breastfeeding as compared to the children who were not delivered by C-section. Dhaka Univ. J. Sci. 69(1): 23-29, 2021 (January)

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