Transferring Data Between R and Excel

For a long time, I assumed that the only way to transfer data between R and Excel was to do something like the following:

write.csv(x=some.data.frame, file="some_file.csv")

and then to open the resulting CSV file in Excel.  I didn't like doing this, because by the end of an analysis I would have a bunch of temporary "deleteme.csv" files cluttering my Desktop.

It turns out there is a better way to move data between R and Excel:

Move Data from R to Excel

First, from R:
write.table(x=some.data.frame, file="clipboard", sep="\t")

This command copies the specified data frame (not sure how well it works with other object types) to the system clipboard.

Then all one needs to do is open a new workbook in Excel and Ctrl-V (paste) the data into the workbook!  Easy as pie!

Move Data from Excel to R

First, in Excel, select the data you would like to copy, then copy it (Ctrl-C).

Then, in R:
data.from.excel <- read.table(file="clipboard", sep="\t")

That's all there is to it.  This will allow you to quickly and easily transfer data between R and Excel, or more generally, between R and any program that can read data from the clipboard.

Excel Changes Values and Formatting when Importing CSV

When opening a text-based data format with Excel (CSV, tab separated, etc.) you will find that Excel has a nasty habit of automatically interpreting the data types of the cells.  Once it (thinks it) has determined the proper data type, it will also reformat the data to its default formats for numbers, currency, dates, times, etc.

For example, I work with data that involves a lot of timestamps.  I frequently have timestamp data in a MySQL database that looks like this:

   2011-11-30 13:56:02

This is a typical timestamp format that is recognized by many different programs and programming languages.

Usually I will export data from the database into CSV format and load it into Excel to do some tweaking before I turn it into a visualization.  However, when reading the data from the CSV file, Excel, detecting it as a date/time value, will reformat it according to its default formatting rules, like this:

   11/30/2011 13:02

If I then save the CSV file, Excel will save it out using its default format (MM/dd/yyyy hh:mm) instead of my original format (yyyy-MM-dd hh:mm:ss).

Yes, ladies and gentlemen, Excel just changed my values and corrupted my data.

Here is how to prevent this from happening:

1. In Windows Explorer rename the file, changing the extension from ".csv" to ".txt".  (If you don't see file extensions, do the following:
1. Press the Alt key in the Explorer window.  (This will make the menu bar visible.)
2. In the newly visible menu bar, select Tools -> Folder Options ...
3. Click on the "View" tab.
4. UNCHECK the box that says "Hide extensions for known file types."
5. Click OK.
6. You should now be able to see the ".csv", ".txt", ".whatever" extensions on the file names.
2. In Excel, open the newly renamed file.  (You will probably need to change the file type selector to "All Files (*.*)" in order to find your .txt file.)  After clicking "Open", Excel will present you with a window titled "Text Import Wizard - Step 1 of 3".
3. In Step 1, choose the "Delimited" radio button.  Click "Next".
4. In Step 2, in the "Delimiters" section, check the "Comma" box (or whatever delimiter your file is using) and make sure that all other delimiter boxes are UNCHECKED.  You should now see your data divided into the appropriate columns at the bottom of this window.  Click "Next".
5. In Step 3, click on the first column.  Use the scrollbar to scroll over to your rightmost column.  Hold down the Shift key and click on the final column.  All columns should now be selected.
6. Click on the "Text" radio button in the "column data format" section.  Now click "Finish."

Following these steps, Excel will NOT try to automatically determine a data type, nor will it reformat or change your data in any way.

Continuously monitoring open files in real-time

Recently, I wanted to be able to get a list of files that were being opened by a running process.  Searching all over the web, I found a number of solutions, but they all involved using the lsof command.

The lsof command has many, many options, and it allows you to see which files have been opened by a given process. Coming the other direction, it also allows you to see which process has opened a given file. I can see how it would be extremely useful in many different circumstances.

However, my problem was that my process was opening files and closing them almost immediately. In other words, I had no hope of using the lsof command to view open files, because lsof only shows files that are currently open, and by the time lsof would run, the files were already closed again!

I discovered a different way to continuously monitor, in real-time, all of the files that were being opened by a process, regardless of how quickly they were closed:

strace -tt myprog 2> system_calls.txt
grep 'open(' system_calls.txt > opened_files.txt

strace is a command that logs all of the system calls for myprog.  The -tt option includes a timestamp (with microseconds) at the beginning of each line. Each file is opened with a call to "open(", so grepping for this string should give you a list of all files that were opened.

Installing Ubuntu 10.04 (Lynx) x86_64 Server on Dell XPS 630i

Recently, I needed to install Ubuntu on a Dell XPS 630i.  There was one irritating problem: the installation cd would consistently freeze just after selecting "Install Ubuntu" from the main menu, leaving me with a blinking white cursor and the inner turmoil that can only be experienced while wondering whether your computer is actually doing anything

I've never had these kinds of problems installing Ubuntu before, and I wasn't really sure where to start troubleshooting.  A number of forum websites with postings similar to my own situation recommended changing some of the install parameters, such as noapic, nolapic, noacpi, etc.

None of this worked.

I finally found this post on a Dell community forum, which ingeniously suggested to:

1. Install Ubuntu 8.04 (Heron) x86_64 Server


2. Check for updates in the package manager.  Install all UPDATES (NOT distribution upgrade)


3. Restart


4. In a terminal, sudo update-manager --devel-release


5. Check for updates one more time.  THEN click on the button at the top of the package manager window to install the distribution upgrade to arrive at 10.04 (Lynx).

I never would have thought of that.  I followed the post instructions exactly.  Success!  Everything appears to be working just fine.  Here's to you, jakeman66.

Keeping a remote process running after terminal disconnect

Quoting TheOneKEA at http://www.linuxquestions.org/questions/linux-general-1/keeping-a-process-running-after-disconnect-150235/:

nohup is what you want - it's a wrapper that blocks the SIGHUP signal sent to all applications connected to a terminal when that terminal is closed by the shell.

Just ssh into the box and start the command using this syntax:

[user@remoteboxen user]$ nohup /path/to/command arguments &

The man page explains it better.

Rebuilding the VirtualBox Kernel Modules (Ubuntu 9.04)

Any time there is a kernel update, you would do well to rebuild the VirtualBox kernel module to ensure compatibility with your new kernel version. This can be done by executing the following command from the terminal:

sudo /etc/init.d/vboxdrv setup

Installing Fonts in Linux (Ubuntu 9.04)

First, you can find some good free font downloads at http://www.sostars.com.  I downloaded a stencil font called "Ver Army." I unzipped the file, and found a .ttf font file.

I learned how it install it from this page. Here's a summary:

To install Microsoft Windows fonts: sudo apt-get install ttf-mscorefonts-installer
To install Red Hat Liberation fonts: sudo apt-get install ttf-liberation

To install any other kind of font (including the one I downloaded from sostars.com):

1. mkdir ~/.fonts (make a font directory in your home directory if one doesn't exist already)


2. mv ver-army.ttf ~/.fonts (move your ttf file into the .fonts folder)


3. Restart the computer

GNU sed (Stream EDitor)

sed -r 's/\t+/,/g'



sed	invoke the stream editor
-r	use extended regular expressions (similar to using the -E argument for grep). This gives meaning to the '+' character in my regex.
s	tells sed that we are doing a replacement ("substitution") operation
\t+	find occurrences of one or more tab characters
,	replace it with a comma
g	do this substitution for all occurrences of \t+

So, today I had a problem.  A friend needed me to convert a 10 MB data file from tab-separated format to comma-separated format.

"This should take about 2 seconds."

I wasn't on my trusty little laptop (running Ubuntu 9.04 Jaunty Jackalope since March) and was stuck using a lab computer on campus, which was, of course, running Windows XP with no useful utilities whatsoever.  To try to save some time, I tried to do this conversion right on my friend's computer.  We opened the document in MS Word, and tried to do a Find and Replace for tabs, converting them to commas.

Slow.  Killed the program several minutes into the operation.

Next, over to my trusty laptop.  Loaded up jEdit, a handy programming editor that has done well for me in the past.  Tried to do the find and replace.

Also slow.  Killed this about 10 minutes into the operation.  "It really shouldn't be taking this long."  What went wrong?  JEdit was out of memory.  I found that out from the command-line terminal where I launched jEdit.  Hmmm... Maybe some kind of error box would have been nice so I didn't just sit there for 10 minutes wondering. ;)

No more of this garbage.  We're going to the command line.

Always go to the command line.

I already knew about sed, but my memory was a little rusty on the command-line arguments.  After about 10 minutes, I finally found what I was looking for.

Converted the file in about 2 seconds.

Why is it that something that should take 2 seconds always takes 30 minutes?

Shell script for Google search result parsing

This is the shell script I wrote to help me perform the analysis I did for Quest 5.

1. Perform a site:yoursite.edu search in Google, displaying 100 results per page.
2. Save each page (Google will only give you 10 at most) into a folder named yoursite.edu
3. Download the shell script to the directory that contains the yoursite.edu directory.
4. At the command prompt, type:

./google-results-parse yoursite.edu

5. OR, if you named the yoursite.edu directory something different, run this:

./google-results-parse yoursite.edu savedresultsdirectory

6. It will create a "savedresultsdirectory-parsed" directory, which will contain a "domainlist" file and a "pagelinks" directory. The "domainlist" gives the subdomain breakdown of the search results.  The "pagelinks" folder contains files for each subdomain that include all of the search result URLs for that subdomain.

Download the file here.

Open Ed. Quest 5 -- Searching for a Better Way (to Search)

Quest 5

"Many BYU faculty already openly share their syllabi and other course materials on personal websites, through iTunesU, and through other mechanisms ... Find as many of the open educational resources being shared by BYU faculty as you can..."

It seems to me that discoverability is really going to be the ultimate make-or-break hinge issue for OER.  One could produce world class, high quality OER that trumps everything that any institutional OER effort produces, and yet remain in complete obscurity with no hope of ever actually sharing these wonderful OER with anyone at all.  And after all, if you take the time and trouble to make some kind of resource with openness in mind, it seems silly to have it be completely worthless (or at least, gravely underused) in the end because you weren't able to put it somewhere that people would find it.

This post isn't going to discuss the hows and whys of publishing open educational content for maximum discoverability. We'll save that for another time.  However, Quest 5 gives us the specific assignment to comb over BYU's web presence looking for faculty-produced OER content, and it begs the question, "How would one go about finding all of the OER on a university's web space?"

The task is not trivial.

Copyright in Distance Education

(It is at this time that I would like to make a plug for Creative Commons licenses.  Thank you.)

I think I've talked more about copyright this semester than at any other time in my entire life.  This is not surprising, however, as I would guess that I am like most people in many respects, and I am assuming that most people aren't well versed in the subtle nuances and intricacies of US copyright law, including the Digital Millenium Copyright Act (DMCA) and the Technology, Education, and Copyright Harmonization Act (TEACH).

What a mouthful.

Accessibility in Online Distance Education Courses

A while back I ranted about Google's CAPTCHA human detection implementation, and how it is practically impossible sometimes to sign up for a Google Account.  But the moment of truth arrived when I listened to the accessibility recording of the CAPTCHA.  In case you forgot, I can summarize it with one word -- psychotropic.  (Usual disclaimers against drug use apply.  Seriously, kids, don't do drugs.)

So, this experience made me start thinking.  I've done my fair share of web development.  So, it's not like I was completely unfamiliar with accessibility issues.  I know that images need to have alternate text, I know that it's good practice to put a "Skip to the Content" link at the top of the page to skip over navigational links, etc., etc.  However, I didn't really begin to understand what it was all about until finally having an experience on the web were I was prevented from doing something I wanted to do because my senses were unable to decode the information being presented to me.

Quest 2 - For Real Now

Up to this point in the course we've done a lot of talking.  We've had great discussions about the history of the open education movement, usage rights, sustainability models, reusability, remixability--even hippies!--and just about everything in between.  But now it's time to get to work!  No more talking!  This is going to be fun.

So, looking ahead to Quest 6, we in our guilds will need to collaborate to create a course entirely out of open educational resources.  Because we have so little time left, we decided as a class that we would devote everything we do in the remaining quests to work toward our goals for Quest 6.

The course that we as a class originally (more on that later) decided to build is 10th grade social studies--World Civilizations.  We will attempt to build this course entirely from OERs that meet the Utah State K-12 Core Curriclum Standards for World Civilizations.

So I decided that for Quest 2 I would just jump into the pool and do my best to find as many OERs as possible that could help us meet the objectives and standards set out in the Utah K-12 Core.  This actually turned out to be the first time I've ever made a real attempt to collect a large number of OERs from multiple repositories for a single purpose.  Everything that follows here is a description of my first purposeful experience looking for OERs.

If at any point you feel like cutting to the chase, click on this link or just scroll to the end.

Accessibility Issues are No Laughing Matter

Except this one really made me laugh quite loudly.  I was trying to create a new Google account so there would be a webmaster email address for the BYU PSST research group's website.  As I went about happily filling out information for this new account, I suddenly hit a wall when Google wanted me to type in some letters that looked all swirly and mashed together like a trick one's eyes might be playing when one has been smoking peyote.  (I would, at this point, like to disclose that I have never actually smoked peyote and don't know if the preceding comparison is a good one or not.  I would also like to discourage anyone from smoking peyote to find out.  Moving on.)

History and Status of OER at BYU (DRAFT)

While the social climate for a policy of openness at BYU is currently in its nascent and humble stages, it is quickly gaining momentum.  Despite the lack of an official university-wide “open” policy at BYU, a number of open activities are already well under way.  To date, a growing number of OERs and OER-like resources are already offered through various channels on campus.

BYU Independent Study is one example of an organizational effort to contribute to the OER community.  IS already offers free access to a selection of their courses for personal development.  Additionally, IS will soon launch a pilot program to offer several of their most popular courses to all BYU students and the general open education community in a manner similar to OER initiatives currently underway at other universities.

One more such organizational effort is based in the McKay School of Education, which recently launched a pilot program to openly publish (with voluntary instructor participation) several School of Education courses.

In addition to these organizational efforts, many BYU faculty have, as individuals, posted personally developed course content in various ways to make these resources available to the general public.  Some faculty post course syllabi, reading lists, and other course content on personal websites, while other faculty have even recorded their lectures and published them on well known online media repositories such as iTunes and YouTube.

While each of these efforts is a step in the direction of openness, the efforts are typically isolated from each other.  The real power behind these efforts will be found in strength of numbers and unity of purpose.  Because many departments and individuals at BYU are already beginning to contribute to the OER movement, there is a clear need for a central repository of BYU-produced OERs.  The Center for Teaching and Learning is clearly the organization with the resources and momentum toachieve such an undertaking.

(Distance Ed) Week 6 - Findings

Article	Findings
Dalsgaard, C., & Mathiasen, H. (2008). Self-organized learning environments and university students' use of social software: A systems theoretical perspective. International Journal of Instructional Technology and Distance Learning, 5(2). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Feb_08/article01.htm.	Finding: "The study of the two project groups suggests that a conference system offering asynchronous discussion forums and file sharing has the potential to support students' self-organized learning environment." My thoughts: The results of this study were not earth shattering.  Nor were they particularly bold.  I felt that they were timid, hedging their conclusions.  They concluded that social software in general can help support a self-organized learning environment.  I wouldn't have thought to argue with that in the first place, but it's good that they're not assuming anything, right? Finding: "Given that students are allowed to work independently and are provided with a range of tools, they are excellent in choosing the right media in a given context." My thoughts: I'm not sure that this study (with a sample size of 4) really justifies the generalization that "students are excellent in choosing the right media in a given context."
Ganjooei, B. A., & Rahimi, A. (2008). Language learning strategy use for EFL E-learners and traditional learners: A comparative study. International Journal of Instructional Technology and Distance Learning, 5(12). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Dec_08/article01.htm.	Finding: "the education system has little influence on the way learners usually go about applying language learning strategies." Finding: "No significant differences were observed in regard to the frequency of occurrence of learners' use of strategies." My thoughts: I thought this was a valid research question, and I think it is interesting to see that there is no difference between online and F2F students regarding usage of learning strategies. Finding: "Learners with high language proficiency level showed more effective use of strategies whereas the learners with low level of proficiency usually failed to choose the appropriate learning strategies in their process of language learning." Finding: "There is a positive correlation between language proficiency level and application of subcategories of language learning strategies." Finding: "Analyzing the results from one-way Analysis Of Variance (ANOVA), one could claim that there were differences regarding language learning strategy use in each proficiency level, but contrasting each proficiency level two by two, no significant differences were observed." Finding: "Both language learning strategy use and language proficiency level can be predicted by each other." My thoughts: The study was well thought out, planned, and seems (in my limited knowledge of what good research is all about) to be rigorous in its methodology.
Gouge, C. (2008). Redesigning online instruction: theory and application. International Journal of Instructional Technology and Distance Learning, 5(2). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Feb_08/article04.htm.	Finding: "Evaluations showed that what students valued most about the structure of the course was not any one individual demonstration or other aspect of the course (no matter how sophisticated the technology used to support it);" Finding: "students reported that they appreciated the variety of interactivity and opportunities to communicate with me and their classmates encouraged and made possible by the course structure." Finding: "90% of students cited the message board interaction with me and their peers as the most useful to their learning in the course." My Thoughts: This was a nice case study, Interesting to hear her personal results from this particular course redesign
Holbein, M. F. (2008). From traditional delivery to distance learning: Developing the model. International Journal of Instructional Technology and Distance Learning, 5(8). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Aug_08/article05.htm.	Finding: "Sitting in a classroom and listening to a lecture or small group discussion can actually be quite passive. Online learning is active and alive. Beyond the technology and instructional design lies the human element. Students want and need to be connected. The challenge for instructors is to help them build a sense of community so that while they may not see one another face-to-face, they know one another and share their ideas thereby contributing to learning for all." My thoughts: This one was more theory-based and focused on the importance of building community and interaction for an online setting to be instructionally effective.
Kiriakidis, P., & Parker, A. (2008). Faculty and learner interaction in online courses. International Journal of Instructional Technology and Distance Learning, 5(11). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Nov_08/article03.htm.	Finding: The relationship between the extent of faculty interaction and the extent of learner interaction in online courses was found to be of statistical significance (r = .763, p < .01). " Finding: "The findings of this study suggest that there is a direct relationship between faculty and learner interaction in online courses." My thoughts: No argument here.  Teachers interact with students more = students interact with teachers more.
Kok, A. (2007). Metamorphosis of the mind of online communities via E-Learning. International Journal of Instructional Technology and Distance Learning, 5(10). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Oct_08/article03.htm.	Finding: "Recognizing the learners' input, providing opportunities to develop a sense of group cohesiveness, maintaining the group as a unit and helping learners to work collaboratively may increase the effectiveness of online communities." My thoughts: Mostly theory based; conclusions seem valid.
Kupczynski, L., Davis, R., Ice, P., & Callejo, D. (2008). Assessing the impact of instructional design and organization on student achievement in online courses. International Journal of Instructional Technology and Distance Learning, 5(1). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Jan_08/article01.htm.	Finding: "The original intent of this study was to determine if a relationship existed between instructional design / organization and student performance in online courses. None of the three methods revealed a relationship between the predictor and criterion variables."
Royal, P., & Bell, P. (2008). The relationship between performance levels and test delivery methods. International Journal of Instructional Technology and Distance Learning, 5(7). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Jul_08/article05.htm.	Finding: "There was a difference between student performance and test delivery method. However, the overall difference was not significant." My thoughts: Surprising.  I would've thought that there would be a much higher achievement rate on exams that were non-proctored.
Shi, S., Bonk, C., Tan, S., & Mishra, P. (2008). Getting in sync with synchronous: The dynamics of synchronous facilitation in online discussions. International Journal of Instructional Technology and Distance Learning, 5(5). Retrieved January 12, 2009, from http://www.itdl.org/Journal/May_08/article01.htm.	Finding: Moderators effectively moderate an online  group discussion by posting messages with "hooks on both ends" Finding: "When a moderator was demonstrating and modeling, hopefully within the zones of proximal development of most or all of the participants and coupled with deep engagement with real issues related to the topic, participants were drawn into the discourse. Finding: "when individuals operate on each other's reasoning, they become aware of contradictions between their logic and that of their partners. The struggle to resolve these contradictions might very well propel them to new and higher levels of understanding." Finding: Moderators can effectively moderate an online group discussion by establishing group norms. Finding: Moderators can effectively moderate an online group discussion by trying to accommodate for students' social-emotional needs. My thoughts: A "best practices" type of article.  From their experience, they collected a number of things moderators can do to provide high quality online group discussions for distance education situations.
Young, B., Hausler, J., & Sanders, J. W. (2008). Do online students exhibit different learning styles than onsite students? International Journal of Instructional Technology and Distance Learning, 5(4). Retrieved January 12, 2009, from http://www.itdl.org/Journal/Apr_08/article02.htm.	Finding: "While we found students who preferred visual learning were slightly less inclined to prefer online classes, we found no one discernable learning style to be prevalent in most of our online classes.  Preferences were more likely dictated by other considerations than learning styles." My thoughts: This finding was surprising to me, and I think it made for a good study.  I would have thought that online courses would appeal to a specifically different type of learner.

Quest 1 - Reusability in the Land of OERs

Aaron's Rogue Quest 1

"Carefully review the following sites that publish open educational resources, noting the types of media predominantly used by each site and any site characteristics that seem unique. Pay close attention to the quality of reusability exhibited by the media from each site.  Be certain to review a sufficient sample of courses per site to gain accurate insight into their practice. Write a substantive post with references on the variety of media, touching on the reusability aspect of each medium type you encountered."

In this post, I have sampled a number of courses from each of the following websites that offer open educational resources.

MIT OCW
Berkeley
Yale
Stanford
Carnegie Mellon Open Learning Initiative
Connexions
Open University of the UK

Throughout the rest of this post, I intend to discuss each of the different media types of OERs that I found on these sites, discussing their strengths and weaknesses with particular regard to the 4 Rs of Reusability and the SLAM (or, less violently, the ALMS) analysis (from our in-class discussion on 15 Jan. 2009).

(Distance Ed) Week 5 - Theoretical Foundations

So, here is a brief synthesis of the theoretical foundations from the 10 articles I chose.

Constructivist

Also, Garrison was quoted a number of times in the context of "communities of inquiry." Several of the papers didn't really boast of anything that could be considered a theoretical foundation. Or if they did, they sure didn't make it explicit. How annoying.

In response to Charles' thoughts on Learner Autonomy

This post originally started out as a comment reply to a comment from Charles in reply to this post. (Sorry, couldn't think of a better way to write that.) It eventually became long enough to become a post of its own, and thus worth more points for my Distance Ed class. (YEAH!)

"In my view learner autonomy can be a good thing and a bad thing."

You know, you are absolutely right. At first I disagreed with your statement, thinking that we had just been using a different definition of "learner autonomy." I was using the phrase to designate only the quality and extent of the autonomy characteristic exhibited by the learner, and I thought you were using it to describe the degree of autonomy encouraged or allowed by the instructor.

However, despite the possibility of our using different definitions of the phrase, I am nonetheless forced to agree with you after more careful consideration of the matter. Imagine a classroom full of learners who are fully autonomous, needing no help at all from the teacher, and can come to all of the correct answers on their own, solely through interaction with the textbook. (Please ignore for a moment, if you will, the fact that the situation just described is, arguably, a contradiction.) Now, imagine a classroom full of students who, in order to truly learn the content, desperately need the instructor to hold their hands and spoon-feed them all course content. The first scenario I described sounds much less easier to me as an instructor, and thus much more appealing. So learner autonomy is obviously a good thing, right?

Moore's Theory of Transactional Distance

While reading several of Moore's descriptions of his own Transactional Distance Theory (hereafter TDT), I found myself saying unusually large numbers of "yeps" and "uh-huhs". This is troubling to me, only because I tend to think that sometimes I do not read academic literature with a sufficiently critical eye. However, based on my observations of those students in my graduate program that are senior to me, I believe that developing a healthy sense of skepticism is inevitable (although to what extremes it can still be considered "healthy" is debatable). But, I digress.

Still, I think he's got a good theory here! In any case, I felt like I could understand and relate to a lot of Moore's ideas. Of course, I haven't done any empirical research myself on this theory, but everything he stated seems congruent with my recollection of my own experiences. And where my experiences are different from others' experiences, I don't have to work too hard to imagine how it might still apply to them as well.

I won't attempt to cover everything about the theory here (no sense in rewriting Moore's work), but I think it will be helpful to clarify what the major points of his theory are, and I may write a few thoughts on them as I go along.