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What's New in the Interactive Statistical Pages

Number Needed to Treat (NTT) Calculator -- you enter the risk of outcome for the treated and control groups, and this page will calculate the absolute risk reduction (ARR), relative risk (RR), relative risk reduction (RRR), and number needed to treat (NNT). This page also contains a handy table showing NNT for various values of control group risk and relative risk, and a chart illustrating the relationship. (added 11/06/2014)
Affordable Colleges Online -- provides free higher education tools and information for current and future college students and their families. Focusing mainly on the not-for-profit programs, this site provides guidebooks for veterans, students with disabilities, Hispanic students, and other college hopefuls; an in-depth financial aid section with articles, guides, expert Q&As, and walkthroughs of key processes and forms; an expert-driven, 20-page guide to online learning success; and a directory of introductory Massive Open Online Courses (MOOCs) from top universities. (added 10/18/2014)   The web site contains a Graduate Degree Guidebook to Online Masters Programs that discusses online master's degrees and program options, and includes helpful information regarding accreditation, time expectations and deadlines, and other frequently asked questions. (added 11/06/2014)

Guide to College Internships -- a student's guide to skillfully locating, bargaining and accepting Internships.  Part of the web site, which also contains several other guides, lists of colleges and online degrees, and several rankings of colleges by net price, selectivity, and graduation rates. (added 10/09/2014)

Online MBA Programs -- part of the Affordable Colleges Online web site. MBA career guide tailored to the needs of current and future MBA students. The guide includes several key sections, including industry resources, career path outlines, supplemental free online courses, an MBA specialization matrix, and moreThe developers of this page worked with two career counselors and an MBA student to create this content with the intention of providing actionable, relevant, and timely information. (added 10/08/2014)

a very polished calculator for two-group Student t test, with graphical display of means and confidence intervals, and an interpretation of the results. Can take individual values or summary statistics (N, mean, SD) for each group. (added 10/04/2014)

Comparison of two proportions between two groups (each given as # successes / # of trials). Shows confidence intervals, and interprets the results of the comparison. (added 10/04/2014)

a very polished calculator for comparing two event rates (number of events in a certain amount of time). Shows confidence intervals around each event rate, and interprets the significance of the difference between the rates of the two groups. (added 10/04/2014)

Kaplan-Meier Survival Plot and LogRank -- calculates survival curves (with confidence bands), and performs a LogRank test test to  comparing survival curves between two groups. (added 10/04/2014)

Compare Average Survival Time between two distributions -- Enter the number of events and the average time to event for each of two groups. The calculator will display the confidence interval around each mean time, and will compare the two mean times. (Assumes an exponential-shaped survival curve.) (added 10/04/2014)
Required sample size for comparing proportions between two groups (added 10/04/2014)

Wizard -- (for Macintosh only), provides all basic statistical tests, emphasizes easy-to-understand, graphically-based results. Imports data from text files, spreadsheets, SQL databases,  and R workspaces (the Pro version can also import SAS, Stata and SPSS files). The free trial versions (standard or Pro versions) never expire; they don't provide p values, or export/save. (added 10/04/2014)

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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