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Affordable Online Colleges in America: Rankings & Report -- Edudemic's web site provides information about the most affordable colleges online today. 180 online colleges are ranked on student value, price, and reputation, to determine objectively how far a dollar takes you at each one. These colleges had the best balance of low tuition and stellar performance metrics. (added 09/20/2014)
HTML for Beginners -- A nice introduction to HTML, describing the concept of markup tags, preparing an HTML document, using meta-tags, basic formatting, hyperlinks and anchors, images, forms and tables. It also contains links to other HTML resources. Thanks to the young web designers at the W. B. Goodwin Community Center for suggesting this resource!  (added 07/23/2014)

RegressIt - An Excel add-in for teaching and applied work.  Performs multivariate descriptive analysis and ordinary linear regression.  .  Creates presentation-quality charts in native editable Excel format, intelligently formatted tables, high quality scatterplot matrices, parallel time series plots of many variables, summary statistics, and correlation matrices.   Easily explore variations on models, apply nonlinear and time transformations to variables, test model assumptions, and  generate out-of-sample forecasts.   Includes audit trail and organization features: output stored in separate worksheets, date/time/username worksheet stamps, unique model names in all table and chart titles, and an additional worksheet with side-by-side comparisons of models. (added 05/23/2014)

Develve -- stats package for fast and easy interpretation of experimental data in science and R&D in a technical environment. Everything is directly accessible and  results are directly visible, with no hidden menus; e.g.:  graphs are easily scrollable, and when clicked, a bigger version pops up. Results for group comparisons directly indicate the significance of the difference in average and variation, and if the sample size is sufficiently large. Has a basic mode for statistical testing, and a design-of-experiments mode. (added to Free Software page on 03/27/2014)

 ID Hunter -- a comprehensive listing of online graduate certificates in instructional design, online teaching, e-learning, and related fields, along with info on credit hours required, costs, application requirements, and related master’s programs. The website is free to use and requires no registration. (added to Other Links page on 03/27/2014)

Diagnostic Test Evaluation -- From a 2x2 cross-tab of diagnostic test results (positive or negative) vs. true disease state (present or absent), calculates sensitivity, specificity, positive and negative likelihood ratios and predictive values, and disease prevalence, along with their 95% confidence intervals. (added 03/06/2014)

Textbook rental for the duration of a course can save you 80 to 90% of the cost of buying the textbook outright. (added 02/25/2014)

An interactive homework-tutoring system for math (including algebra, geometry, trigonometry, calculus, probability and statistics). A paid service, but there's a 7-day free trial. (added 02/25/2014)

Check out the web site, which contains (at last count) 19 interactive calculators for power or  required sample size for many different types of statistical tests: testing 1 mean, comparing 2 or more means, testing 1 proportion, comparing 2 or more proportions, testing odds ratios, and two 1-sample tests (normal and binomial-based). This site also provides calculators for non-inferiority and equivalence studies. The web pages display graphs that dynamically show how power varies with various design parameters as you change other parameters. (added 02/18/2014)

3-D Regression and Interactive Graph (by MiaBella LLC) -- a powerful web page that fits a linear function of two predictor variables (Z = a + b*X + c*Y), and displays a very elegant 3-D scatterchart of the {X,Y,Z} points and the fitted plane. You can rotate the graph in three dimensions using the mouse, and you can see the X, Y, and Z values of any point (say, an outlier) by clicking on the point. (added 01/27/2014)

Mometrix Academy - a set of free videos to help you prepare for various kinds of standardized tests (ACT, GED, GRE, SAT, LSAT, MCAT, and others), and to improve your general knowledge in various areas (business & finance, English, health & fitness, humanities, mathematics, medical, science, and teaching). These videos are presented as a public service of  Mometrix, The World’s Most Comprehensive Test Preparation Company™. The main purpose of this site is to offer free, practical test-taking advice. If you like the content of these videos and you're taking a test in the near future, you may want to look at their more comprehensive study resources at the Mometrix Home Page.

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