## Educational web applications

### Overview

Working with my postdoctoral advisor, Roger Peng, I have developed R software that allows someone to create a complete web application by creating question templates using the R language. Since this software requires no knowledge of PHP or other languages commonly used for web applications, it allows academics who know only R to create sophisticated web-based problem sets. I have used this software to develop or direct development of web applications for two Master's level Biostatistics courses at Johns Hopkins Bloomberg School of Public Health.

### Screenshot Demonstration

These web applications can only be accessed by members of the course for which they were developed. However, I created this screenshot demonstration to show students how to use the web applications, and it walks through one of the web applications we created. This web application was for the Biostatistics 611, a Masters' course in Statistical Reasoning at Johns Hopkins Bloomberg School of Public Health.

### Pilot Tests

#### Biostatistics 653, *Methods in Biostatistics III*

In Spring 2012, I worked with Roger Peng and his teaching assistants to develop a web application with homework and practice problems for this course. The course covers linear regression and is offered to students pursing a Masters' degree in Biostatistics at Johns Hopkins Bloomberg School of Public Health, as well as students from other departments of JHSPH interested in mathematical biostatistics. Approximately 30 students were enrolled in this course.

The web application we created with Bespoke Homework served two functions. First, the entire first homework was administered and graded through the web application. This homework included 10 question types, each randomly generated 30 times to provide multiple examples. To get full credit for the homework, a student had to continue answering questions until he had successfully answered, for each question type, three of the last four questions attempted.

Second, we created a practice set of problems to help students study for the Midterm Exam. This practice set included about 30 question types, each randomly generated to get 30 separate versions of the question. Students could choose to practice by topic or to use a self-graded option to access their progress through the material.

#### Biostatistics 611, *Statistical Reasoning in Public Health I*

In Fall 2012, I worked with John McGready and Aaron Fisher to develop a web application to provide students additional practice problems. This course introduces students at Johns Hopkins Bloomberg School of Public Health to the concepts and techniques of Biostatistics. This year's course included over 200 students, with approximately half taking the course online and half onsite.

For this web application, Aaron Fisher used my Bespoke Homework software to develop the content for the set of practice problems, and I administered the web application during the course. This pilot test allowed us to try out a web application in a very large class with a significant group of online students. While we did not use the web application for any graded assignments, the success of the web application for this course showed that this type of web application could be successful used for graded homework in a large course in the future.