Publications by matloff
Online But In-Class Examinations (with an R Example)
About a year-and-a-half ago, some students and I wrote OMSI, Online Measurement of Student Insight, an online software tool to improve examinations for students and save instructors lots of time and drudgery currently spent on administering exams. It is written in a mixture of Python and R. (Python because it was easier to find students for the p...
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A Partial Remedy to the Reproducibility Problem
Several years ago, John Ionnidis jolted the scientific establishment with an article titled, “Why Most Published Research Findings Are False.” He had concerns about inattention to statistical power, multiple inference issues and so on. Most people had already been aware of all this, of course, but that conversation opened the floodgates, and ...
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More on R and Reproducible Research
Readers who found my posting last week on our revisit package of interest may wish to check the somewhat related package ropensci/rrrpkg, which Edzer Pemesma tweeted about today. Related To leave a comment for the author, please follow the link and comment on their blog: Mad (Data) Scientist. R-bloggers.com offers daily e-mail updates abou...
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My Presentation at useR! 2017, Etc.
I gave a talk titled, “Parallel Computation in R: What We Want, and How We (Might) Get It,” at last week’s useR! 2017 conference in Brussels. You can view my slides here, and I think the conference organizers said the videos would be placed online, not sure of that though. The goal of the talk was to propose general design patterns for pa...
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Understanding Overhead Issues in Parallel Computation
In my talk at useR! earlier this month, I emphasized the fact that a major impediment to obtaining good speed from parallelizing an algorithm is systems overhead of various kinds, including: Contention for memory/network. Bandwidth limits — CPU/memory, CPU/network, CPU/GPU. Cache coherency problems. Contention for I/O ports. OS and/or R limits...
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Update on Our ‘revisit’ Package
On May 31, I made a post here about our R package revisit, which is designed to help remedy the reproducibility crisis in science. The intended user audience includes reviewers of research manuscripts submitted for publication, scientists who wish to confirm the results in a published paper, and explore alternate analyses, and members of the ori...
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Wrong on an Astronomical Scale
I recently posted an update regarding our R package revisit, aimed at partially remedying the reproducibility crisis, both in the sense of (a) providing transparency to data analyses and (b) flagging possible statistical errors, including misuse of significance testing. One person commented to me that it may not be important for the package to in...
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cdparcoord: Parallel Coordinates Plots for Categorical Data
My students, Vincent Yang and Harrison Nguyen, and I have developed a new data visualization package, cdparcoord, available now on CRAN. It can be viewed as an extension of the freqparcoord package written by a former grad student, Yingkang Xie and myself, which I have written about before in this blog. The idea behind both packages is to remedy ...
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Regression Analysis — What You Should’ve Been Taught But Weren’t, and Were Taught But Shouldn’t Have Been
The above title was the title of my talk this evening at our Bay Area R Users Group. I had been asked to talk about my new book, and I presented four of the myths that are dispelled in the book. Hadley also gave an interesting talk, “An introduction to tidy evaluation,” involving some library functions that are aimed at writing clearer, more ...
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Xie Yihui, R Superstar and Mensch
Yesterday a friend told me, “Yihui has written the most remarkably open blog post, and you’ve got to read it.” I did and it was. Though my post here is not about R per se, it is about a great contributor to R, our Yihui, Dr. of Statistics and (according to him) Master of Procrastination. I can relate to his comments personally, and indeed h...
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