An accessible, R-based suite of statistical applets inspired by Stapplet.com, designed for educational purposes with a strong focus on accessibility, colorblind-friendliness, and WCAG alignment.
This project provides a collection of interactive Shiny applications that mirror the functionality of the popular statistics education website, Stapplet.com. The primary goal is to offer a free, open-source, and highly accessible alternative for students and educators. Each applet is designed to illustrate a specific statistical concept, from sampling distributions and confidence intervals to hypothesis testing and regression.
A key focus of this project is to ensure that all tools are usable by as many people as possible, including those who rely on screen readers and other assistive technologies.
The suite includes interactive applets for:
- Sampling Distributions:
- Distribution of Sample Means
- Distribution of Sample Proportions
- Confidence Intervals:
- CI for a Single Mean (t-Interval)
- CI for a Difference in Means
- CI for a Single Proportion (z-Interval)
- CI for a Difference in Proportions
- Hypothesis Tests:
- Test for a Single Mean (t-Test)
- Test for a Difference in Means
- Test for a Single Proportion (z-Test)
- Test for a Difference in Proportions
- Chi-Square Goodness-of-Fit Test
- Chi-Square Test for Independence
- Probability Distributions:
- Normal, t, Chi-Square, F, and Binomial distribution calculators.
- Regression:
- Simple Linear Regression analysis and visualization.
- ANOVA:
- One-Way Analysis of Variance.
- Tools:
- Descriptive Statistics calculator.
- Probability simulators (coin flips, dice rolls, card draws).
To get a local copy up and running, follow these simple steps.
- R: You must have a recent version of R installed. You can download it from the Comprehensive R Archive Network (CRAN).
- RStudio or VS Code: It is highly recommended to use an IDE like RStudio Desktop or VS Code with the R Extension.
- Clone the repository:
git clone https://github.com/your_username/StappletSHiny.git
- Navigate to the project directory:
cd RShinyStapplet - Install required R packages:
Open R or RStudio and run the following command in the console to install all necessary dependencies.
install.packages(c("shiny", "ggplot2", "dplyr", "gridExtra", "BrailleR", "viridis"))
You can run the application in several ways:
-
Using an IDE (Recommended):
- Open the
RShinyStappletfolder in RStudio or VS Code. - Open the
app.Rfile. - In RStudio, click the "Run App" button that appears at the top of the editor.
- In VS Code or Positron, click the "Run App" CodeLens text that appears above the
uidefinition.
- Open the
-
From the R Console:
- Open your R console.
- Set your working directory to the
RShinyStappletfolder.
setwd("path/to/your/RShinyStapplet")- Run the application.
shiny::runApp()
-
From the Command Line (Quick Entry Scripts):
- Use one of the scripts in the
launch_Scriptsdirectory to quickly launch the app from your terminal or command prompt. - Available scripts:
launch_shiny_app.sh(Bash)launch_shiny_app.zsh(Zsh)launch_shiny_app.ps1(PowerShell)launch_shiny_app.cmd(Windows CMD)
- Example usage (from the project root):
bash launch_Scripts/launch_shiny_app.sh
Or on Windows:
launch_Scripts\launch_shiny_app.cmdOr in PowerShell:
.\launch_Scripts\launch_shiny_app.ps1 - Use one of the scripts in the
The application will launch in a new window or your web browser.
This project is committed to being accessible to all users, including those with disabilities. The applets have been developed to align with the principles of the Web Content Accessibility Guidelines (WCAG) 2.1 Level AA.
-
Screen Reader Support:
- ARIA Roles: Proper use of ARIA landmarks (
role="main",role="complementary", etc.) and roles (role="form",role="status") allows screen reader users to easily understand the page layout and navigate between sections. - Programmatic Labels: All form controls are programmatically linked to their labels, ensuring that screen readers announce the purpose of each input.
- Live Regions: Dynamic content, such as calculated results, uses ARIA live regions (
aria-live="polite") to announce updates without interrupting the user's workflow.
- ARIA Roles: Proper use of ARIA landmarks (
-
Text Alternatives for Visuals:
BrailleRIntegration: For allggplot2-based visualizations, theBrailleRpackage is used to generate detailed, human-readable descriptions of the plot's contents. This provides a rich, equivalent experience for users who cannot see the plot.- Descriptive Text: For visuals where
BrailleRis not suitable (e.g., base R plots), a screen-reader-only paragraph describes the plot's purpose, and accompanying data tables provide the raw values for inspection.
-
Keyboard Accessibility: The application is designed to be fully operable using only a keyboard. Users can tab between all controls, use arrow keys for sliders and radio buttons, and activate buttons using the
EnterorSpacekey.
While we have made every effort to ensure accessibility, we acknowledge the following limitations:
- No Formal Audit: This application has not undergone a formal accessibility audit by a third-party expert. True compliance with standards like Title II of the ADA is a legal determination that can only be affirmed through such an audit.
- No Widespread Human Testing: The applets have not yet been tested by a wide range of users with different disabilities and assistive technologies. User feedback is critical to identifying and fixing usability issues that automated tools cannot detect.
- Color Contrast: The color palette and theme have been updated to maximize foreground-background contrast and use colorblind-friendly palettes (including the viridis palette for all plots). All navigation and interactive elements have been reviewed for sufficient contrast and accessibility.
We are committed to improving the accessibility of this project. If you encounter any accessibility barriers, please open an issue on GitHub.
- Accessibility Improvements: All UI elements and tables have been refactored for better screen reader support and keyboard navigation. Unicode mathematical symbols are now rendered as actual characters.
- Colorblind-Friendly Theme: The app uses a high-contrast, colorblind-safe theme for all UI elements and navigation. All plots use the viridis color palette for maximum accessibility.
- Navigation Bar Fixes: Navigation buttons and links now have visible, high-contrast backgrounds and text.
- Unicode Rendering: All Unicode escapes (e.g.,
\u03bc) have been replaced with the actual Unicode characters (e.g.,μ) throughout the UI and outputs. - Quick Entry Scripts: Added
launch_Scriptsdirectory with scripts for Bash, Zsh, PowerShell, and Windows CMD to quickly launch the app from the command line. - Table Accessibility: Large tables on the welcome page have been split into separate tables under clear headings for better screen reader navigation.
- General Bug Fixes: Various UI and accessibility bugs have been fixed, including missing commas, ARIA attribute handling, and button layout improvements.
Contributions are what make the open-source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.
If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".
- Fork the Project
- Create your Feature Branch (
git checkout -b feature/AmazingFeature) - Commit your Changes (
git commit -m 'Add some AmazingFeature') - Push to the Branch (
git push origin feature/AmazingFeature) - Open a Pull Request
If you find a bug, please open an issue and provide a clear description of the issue, steps to reproduce it, and any relevant error messages.
Distributed under the Apache 2.0 License. See LICENSE text below for more information.
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