To transform or not to transform

Estimating log models: to transform or not to transform?

Health economists often use log models to deal with skewed outcomes, such as health utilization or health expenditures. The literature provides a number of alternative estimation approaches for log models, including ordinary least-squares on ln(y) and generalized linear models. This study examines how well the alternative estimators behave econometrically in terms of bias and precision when the...

To transform or not to transform: using generalized linear mixed models to analyse reaction time data

Linear mixed-effect models (LMMs) are being increasingly widely used in psychology to analyse multi-level research designs. This feature allows LMMs to address some of the problems identified by Speelman and McGann (2013) about the use of mean data, because they do not average across individual responses. However, recent guidelines for using LMM to analyse skewed reaction time (RT) data collect...

Folic Acid Supplementation: to Advise or not to Advise?

Differential Transform Method to two-dimensional non-linear wave equation

In this paper, an analytic solution is presented using differential transform method (DTM) for a class of wave equation. The emphasis is on the nonlinear two-dimensional wave equation. The procedures introduced in this paper are in recursive forms which can be used to obtain the closed form of the solutions, if they are required. The method is tested on various examples, and the results reveal ...

Transform Conditionals to Polymorphism

Conditionals —i.e., switch statements, nested ifs— that are used to simulate polymorphism hamper evolution and flexibility of applications. The reengineering patterns presented in this paper show you how to transform conditionals in object-oriented code to improve the flexibility of application. This work has been funded by the Swiss Government under Project no. NFS-2000-46947.96 and BBW-96.001...