- Prof Dev
Calculate the number of respondents needed in a survey using our free sample size calculator. Our calculator shows you the amount of respondents you need to get statistically significant results for a specific population. Discover how many people you need to send a survey invitation to obtain your required sample. You can also calculate the margin of error based on your sample size.
Rseek.org is a search engine for R resources. Type any topic in the search box, and get resources that are R specific. You can further narrow your search to just articles, books, packages, support, or "for beginners."
This online software allows you to load data and make professional-looking graphs with it. Graph types are basic (scatterplot, line plot, bar charts, etc.), statistical (histograms, box plots), scientific (error bars, heat map, contour), 3D charts, and financial (e.g. time series). Other graphs are available with the paid pro version. Log in is required, which allows you to upload data and save it for next use.
This software makes it easier to use the R language. It includes a code debugger, editing, and visualization tools.
This is a web application framework for R, in which you can write and publish web apps without knowing HTML, Java, etc. You create two .R files: one that controls the user interface, and one that controls what the app does. The site contains examples of Shiny apps, a tutorial on how to get started, and information on how to have your apps hosted, if you don't have a server.
This software allows you to extract data from published graphs. There is a web-based app and a downloadable version. First, you provide the software with a picture of the graph in question. Then you give it two points on the x-axis and two points on the y-axis for reference. Then you click on the points on the graph that you want to extract. The points are put into a .csv file.
This is an extensive collection (and a continuously expanding collection) of applets on topics that include probability, descriptive statistics, sampling distributions, Monte Carlo simulation, Buffon's coin problem, chi-square, p-values, correlation, and more. There is even a random number generator that is part of the collection.
OStats is a simple tool for data visualisation and statistical analysis, particularly aimed at helping students learn statistics.