Publications by Francis Smart
Modified Bin and Union Method for Item Pool Design
# Reckase (2003) proposes a method for designing an item pool for a computer # adaptive test that has been known as the bin and union method. This method # involves drawing a subject from a distribution of abilities. Then selecting # the item that maximizes that subject's information from the possible set of # all items given a standard CAT pro...
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A Call for Contributors
Dear Readers,This blog has been going for a year and a half now and I have posted nearly 300 posts to date. I plan to continue to post though I am going to probably continue to shift my focus from daily blogging to that of getting a dissertation together within the next year. In addition, I would like this blog to extend resources...
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Efficiency Balanced Information Criterion for Item Selection
# Han (2012) in the paper "An Efficiency Balanced Information Criterion # for Item Selection in Computerized Adaptive Testing" proposes a method # of evaluating potential items based on expected item potential information # as a function of maximum potential item information. # This method favors items which have lower a values to be initially...
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Consumer’s Choosing an Optimal Bundle – Utility Maximization
# The theoretical basis of classical consumer theory lies # in utility maximization. The idea is that consumers # make consumption decisions based on choosing a bundle # of goods that will maximize individual utility. # Despite this hypothesis being largely unsupported # by reproducible results indicating the superiority # any utility function o...
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The Motivation for the Poisson Distribution
# The Poisson distribution has the interesting property that it # models outcomes from events that are independent and equally # likely to occur. The distribution takes only one parameter mu # which is equal to both the mean (expected number of events) # as well as the variance. # This distribution as with all distributions is somewhat # fasc...
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A Shiny App for Playing with OLS
Ordinary least squares continues to be the staple estimator for causal inference for good reason. In order to help new and veteran OLS users get a better sense of how it is working I have created a shiny app that allows for instant interactivity returning coefficient estimates and prediction graphs through Shiny’s easy to use user interface c...
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A Shiny App for Experimenting with Dynamic Programming
This post demonstrates the dynamics involved in a susceptible, infected, and recovering (SIR) model previous post for the model. The shiny ui and server code can be found on GitHub.of dynamic programming. As a dynamic infection model, I find it particularly satisfying to be able change parameters and observe instantaneously changes in predicted...
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Alpha testing shinyapps.io – first impressions
ShinyApps.io is a new server which is currently in alpha testing to host Shiny applications. It is being designed by the RStudio team and provides some distinct features different from that of the ShinyApps.io is intended for larger applications and I am guessing commercial applications in the long run. Right now it is only allowing users by ...
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A Survey Tool Designed Entirely in Shiny Surveying Users of R
I have written a very basic survey tool built entirely in the Shiny package of R. I hope the tool is useful. Modifying the survey for your own purposes is trivially easy (I hope).I have not commented my code so it is pretty messy right now. You can find the source on GitHub.In order to run your own survey all you need do is edit the Qlist.c...
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Results of an Informal Survey of R users
# This post does some basic correlation analysis between responses # to the survey I recently released through R Shiny at: http://www.econometricsbysimulation.com/2013/11/Shiny-Survey-Tool.html # I have saved the data from the survey after completing the survey myself. # This data is incomplete because the survey has been running since I # saved...
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