SurveyMonkey (popular web data collection service; short surveys free)
Surveyz.com (online survey building and data collection)
PsychData (specializing in social science research)
QuestionPro.com (service for building and analyzing online surveys)
ZipSurvey (web survey application developed by I/O psychologists)
Choosing the Right Tests:
Statistical Decision Tree, from the developers of the MicrOsiris package. This is an interactive set of web pages to help you select the right kind of analysis to perform on your data. It asks you a simple series of questions about your data (how many variables, etc.), then makes recommendations about the best test to perform.
"Selecting Statistics", by Bill Trochim (Cornell). Another interactive set of web pages to help you select the right kind of analysis to perform on your data.
Mx -- a matrix
algebra interpreter and numerical optimizer for exploration of matrix algebra.
Function plotter -- Lets you zoom in and out to view any portion of the graph. (Needs Java.)
Function plotter -- Plot almost any function or relation found in high school and undergraduate college mathematics. Plots functions of the form y = f(x), such as y = x2 or y = 3x + 1, or relations of the form f(x,y) = g(x,y), such as x2 + y2 = 4. (No Java needed.)
Linear Programming Grapher-- Enter a linear function of two variables to be minimized, and any number of linear inequality expressions, and the page will instantly solve it and display a graph showing the feasible region and the constraints.
Simplex Tool -- Similar to the Linear Programming Grapher, but works with functions of more than two variables, and doesn't graph the results.
Probability Distribution
Functions: Tables, Graphs, Random Number Generators
Tolerance Intervals for the Normal Distribution. (Don't confuse tolerance intervals with confidence intervals!) A tolerance interval for a measured quantity is the interval in which there is a specified likelihood that a specified fraction of the population's values lie.
Test for Asymmetry around zero -- Enter a set of numbers (usually a mix of positive and negative numbers), and the program will apply a non-parametric test (originally created by R. A. Fisher) of whether the numbers are consistent with a population frequency distribution that is symmetrical around zero (but does not necessarily have to be normal). It is a frequentist test to work Darwin's experiment with matched pairs, and experiments like it.
Test for the mean being greater than some specified value. This unusual test is Bayesian and frequentist at the same time. The null hypothesis asserts some value for the mean of a population of positive numbers; the alternative hypothesis says the mean is higher than that. This test gives a Bayesian likelihood ratio that is also an upper bound on the p-value of the frequentist test.
Test observed vs. expected rates of occurrence of events, based on Poisson distribution; also includes confidence intervals and analysis of rate-ratios (such as Standardized Mortality Ratio, Morbidity Ratio, and Comparative Mortality Figure)
Compatibility of Multi-Counts -- tests whether up to 14 observed event counts (each over the same amount of time) are consistent with a single expected event rate.
Runs Test for Randomness -- Enter up to 80 numbers, and this page will calculate a runs test to see if the numbers form a random sequence
Testing the Variance -- of up to 80 observations against a postulated population variance.
Test for Normality -- enter up to 42 sets of [value, frequency]; page will calculate skewness, kurtosis, and Liliefors test for consistency with a normal distribution.
Test for Uniform Distribution -- enter up to 42 sets of [value, frequency]; page will calculate the Kolmogorov-Smirnov test for consistency with a uniform distribution.
Testing Poisson Process -- enter up to 14 sets of [value, frequency]; page will calculate a Chi square test for consistency with a Poisson distribution.
Statiscope -- a beautifully-implemented page for calculating and displaying a large number of descriptive statistics from a set of numbers you enter
WebStat (an integrated applet) can generate summary statistics, as well as histograms, stem and leaf plots, boxplots, dotplots, parallel coordinate plots, means plots, scatterplots, QQ plots, and time series plots
Descriptive Sampling Statistics -- Enter up to 80 numbers; this page will calculate the mean, variance, SD, CV, skewness and kurtosis.
Descriptive Statistics -- Enter up to 80 values; page calculates: N, mean, variance, SD, CV, skewness, kurtosis, SEM, median, min, max, range, 1st & 3rd quartiles, interquartile range, quartile deviation, coeff of quartile var, and absolute deviation.
Measuring for Accuracy -- Given a set of observed and predicted values, this page calculates the SD of errors, mean absolute & relative error, and Durbin-Watson statistic.
Basic descriptive statistics (mean, sum of squares, variance, standard deviation, minimum, 25th percentile, median, 75th percentile, and maximum for up to 500 numbers
Multinomial Distributions -- Enter up to 12 values and their corresponding probabilities, and this page will calculate Expected Value, Variance, Standard Deviation, & Coefficient of Variation
Paired Data Sets Statistics -- Enter up to 28 sample paired data sets, and this page will calculate means, variances, and covariance
Histogram -- Enter up to 80 numbers, and this page will display a histogram.
Institute of Mathematical Statistics - The purpose of the Institute is to foster the development and dissemination of the theory and applications of statistics and probability.
American Mathematical Society's home page.
Gives info on membership, activities, and other useful things like
employment opportunities and a preprint server.
A very active professional organization for
statisticians, ASA now has a home page. They have info on membership,
upcoming events, publications, meetings, etc.
The Bernoulli Society is a section of the
International Statistical Institute focusing on probability and mathematical
statistics. Links to membership info and meetings.
The Classification Society of North
America (CSNA) is a nonprofit interdisciplinary organization whose purposes
are to promote the scientific study of classification and clustering
(including systematic methods of creating classifications from data), and to
disseminate scientific and educational information related to its fields of
interests.
RSS home page. Includes links to RSS news,
conferences, membership info, committees, etc. Also includes a link to the
RSS Centre for Statistical
Education.
SIAM home page. Includes the standard links
to membership info, conferences, publications, and career information (nice
because it allows online browsing of job listings from their newsletter,
SIAM News). Also some links
to other math sites. The home page is graphics intensive, so be
prepared to wait if using a slow Internet connection. (This is true only for
the main home page--other pages at this site seem to be mostly text and
transfer pretty quickly.)
Alternates (not hyperlinked):
2008Consulting @ Gmail.com
Help @ DissertationAdvising.com
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