tag:blogger.com,1999:blog-9505187697150221962011-07-08T13:26:23.812-06:00Data Analysis, Statistics, Quality and Presentation.Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.comBlogger131100tag:blogger.com,1999:blog-950518769715022196.post-11007475765123938992010-07-27T10:04:00.001-06:002010-07-27T15:56:27.153-06:00

Scientific writing is sometimes hard to read because of bad grammar, even more than because of strange abbreviations and technical terminology. This is sadly expected in journal articles, even though clear writing will make it more likely that someone will read far enough through your research to use it and cite it. It is also the reason that so many whitepapers are written by non-experts. The

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-84612060004015211412010-07-26T19:13:00.007-06:002010-09-06T12:46:07.445-06:00

It is true that people often like to denigrate statistics derived from survey data, but the reason that I hear most frequently - "But five thousand is less than 0.1% of 300 million!" - is not actually a significant source of error. The error to watch for more carefully is sampling bias. For a long time, "random dialing" has been a great way to get a random sample that could include about 99% of

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-80926966129170076092010-07-22T19:04:00.003-06:002010-07-22T19:11:32.416-06:00

From the realm of hard to interpret statistics based on easy to get data with unknowable biases: From Google searching, with English language set: "single mother" 3,030,000 "single father" 568,000 "single parent" 5,400,000 From"googlefight.com": "single mother" 24,000,000 "single father" 12,800,000 "single parent" 3,670,000 Major news stories have been based on less than this. Easily

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-12042946402437692982010-07-18T13:34:00.009-06:002010-07-26T20:54:40.728-06:00

This post is a re-edit of a half serious note that I was inspired to write by the use of words in a snippet of tongue in cheek conversation about professional statistics. Hopefully this will be found to be an enjoyable read for at least a few people. The inspiration, with no apologies for the really awful pun, stop reading this post now if you can't suffer punning. That's the mood I was in, so it

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-21119900339671031642010-07-14T17:40:00.002-06:002010-07-27T16:00:00.492-06:00

At some point, academics have to give presentations to classes, as students, lecturers, or just simply trying to raise interest in our work. Here's a couple of notes for those terrified of the day they are presenting their research. If using a slide presentation program, have a backup copy on a USB stick. At least with a math audience, there's going to be another working computer in the room. It

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-64811739363809209622010-07-13T01:25:00.000-06:002010-07-18T16:27:40.106-06:00

LaTeX is a typesetting system that mathematicians are expected to be able to use. In a class I am taking, we had a presentation over it, and my response was too long to reasonably post for the class. So I decided to put it here instead. If you ever wonder why a people who live by publishing papers might use something other than Word or other word processor, here's why... Why does LaTeX exist,

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-78364875388448691732010-06-17T09:16:00.006-06:002010-07-18T11:04:27.116-06:00

PowerPoint/ Keynote/ Impress/ other slideshow, or (even better because of wider compatibility) a pdf formatted for projection, is great for PowerPoint sized ideas. Note that Keynote does not have a freely available viewer (thus, no link). If you use it, you are depending on your machine working, or other people having Keynote on their machines. Slide projectors are also rare these days, so be

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-51985819182403810882010-06-04T00:39:00.001-06:002010-07-21T11:29:09.556-06:00

Anscombe (1973) Possibly one of the most famous sets of artificial data sets. And rightly so, if you're not familiar with "Anscombe's Quartet", follow the above link. Now that we've had that graphic reminder to LOOK AT THE DATA, I'm going to skip the usual next step of writing about what to do, and instead refer you, kind reader, to the discussion of this data at the Princeton Office of

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-20428007076668486242010-06-02T14:55:00.004-06:002010-07-23T09:54:11.231-06:00

Yesterday I was helping Jim with a model for predicting non-profit registration by county, and a little problem came up about how to explain some data. He had found a really strong relation, ran the model, and made a pretty choropleth of the results. But the legend had entries like "-0.500 standard deviation to 0.500 standard deviation". And the underlying data had been log transformed. He didn't

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-52391169040777593452010-04-16T09:48:00.006-06:002010-07-21T11:28:48.880-06:00

There are currently four big more-or-less homogeneous markets. By population: China, India, the EU, and the USA. With EU and Indian data, one is quickly aware of the need to detect language early in data processing. While I am not certain about the situation in China, the other "big market" gets certain assumptions made about it. This note covers a "gotcha" about the addresses. When processing

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-27803599384125562582010-04-13T12:18:00.004-06:002010-07-23T11:00:09.050-06:00

The check: Daily average water surface temperature is usually well correlated with the lagging three day average of the daily maximum air temperature. This is robust enough that it can be used as the basis for an interpolation model, and outperforms a lag of the average air temperature. Yes, this summary does skip a lot of analytical details: the tables of correlations between site observations

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-47273019908062178832010-04-09T10:03:00.004-06:002010-07-21T11:27:19.539-06:00

In an effort to simplify things for me, I am making a "data sources" page to merge a large scattered set of references into one place. If you find this helpful for you, I'd be pleased to hear what it helped you with, and perhaps a pointer to the results. In a similar vein, I have started a "software" page. There are so many moving parts in a complete analytical system that I find it helpful to

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0tag:blogger.com,1999:blog-950518769715022196.post-27938228662266471212010-04-08T09:42:00.005-06:002010-07-18T16:26:13.917-06:00

Data Gorilla (noun) - a Data Monkey that has grown up and learned to use power tools. This particular data gorilla uses a lot of windage, common sense and "let's ask what they really meant by this" calls as data power tools, with backup from SAS, R, C++, C, Python, perl, and whatever else is handy. Done previously in contexts of climate research, consumer modeling, behavioral forecasting,

Seanhttp://www.blogger.com/profile/17823438710925543759noreply@blogger.com0