Report Data Ready

The survey data you'll be analyzing for your reports is ready to download. Notice that there is now a new Reports section and that there is a old section (Surveys) missing. If you click on the Reports tab you'll find sub-headers. One of those subheaders is the Surveys section that has now be re-filed under reports.

Much more important to each one of you, however, is that you can go to your group's page. I've labelled groups as 1, 2, 3, 4, and 5. The main Reports page tells you who is in each group. Next go to that respective group page (you'll see the sub-header tabs just under the banner image) and you'll find links to download the data for each of your four members.

Please keep in mind that while the data sets for a group are similar, only one person has the actual "true" data set.

You are free to talk to people within, or outside, of your group. However, talking to other people should be in the form of discussing ideas, getting clearer about statistical concepts, or getting clearer about how to use a spreadsheet. Under no circumstances should these other people be doing the analysis or the interpretation of the data for you.

Session 4 Updates

I have updated the Session 4 page on ANOVA to include the live audio plus the handouts from our class meeting on September 26th. If you want to download either of these, then just go to the ANOVA page in the Learn section.

ANOVA page in Learn section link

Session 5 Materials Ready

All of the learning materials for Session 5 on Inference are ready to download. Make sure you can download these items before this upcoming Saturday class. If you experience problems, then let me know. I'll bring a USB flash drive that you can use to transfer the materials to your computer in class.

session 5 page link

Spreadsheet Form Page

About 25% of you use the latest version of MS Office. In this latest version Word documents are save as DOCX files instead of DOC, and Excel documents are saved as XLSX files instead of XLS. Those 25% of you also know that you have not been able to successfully send me your work using the Spreadsheet form page.

I thought I had fixed all of that about two weeks ago and that this continued problem was something we'd have to live with. Today I discovered I made a really silly mistake. And, of course, now it's been corrected! So starting today onwards those of you using XLSX files made from the newest version of Excel will be able to send me your work from the Spreadsheet form page.

DevSq is the Word

Problem Set 5, originally uploaded by Mathew Mitchell.

Several of you have been posting questions about small rounding off errors. There are a few ways to handle this including: (1) willing to live with small rounding off errors when hand calculating, (2) using Raylene's super-smooth calculation trick (email/phone her), or (3) using your new found spreadsheet skills.

In the end, the real direction you want to go is to become comfortable enough with spreadsheets that you use them for all your basic calculation needs. (The notable exception is that you'll want to use dedicated statistical analysis software for big and complicated analyses.)

1. Spreadsheet Setup
You can easily calculate all of the homework Problem Set 5 answers using your current spreadsheet skills. However, I'm going to make it even easier! First, set up your spreadsheet for the calculations. You should have something like what you see at the top of this post. Note that I've filled in some cells, but left others empty for you to figure out. (All the shown calculations you've already calculated in previous problem sets.)

2. New Spreadsheet Command
The new spreadsheet command that makes life easier for you: DEVSQ. This is a command to figure out the Sum of Squares (or deviations squared) for a specified array of numbers. With this command you do not need to create Deviation and Deviation Squared columns.

Notice that you have three possible DEVSQ commands you'd want to use with the data presented above: SS for the female group, SS for the male group, and SS for the total sample.

3. Calculate
All that is left is to do the calculations. SS Total is very simple since it treats all the data as belonging to one group. SS Within is also straightforward since it's the same thing as adding up the SS for each of your groups. So the one place where you'll really be practicing your formula-creation-chops is figuring out SS Between. That said the formula for this is much simpler than the one used for s_pooled. Finally, eta^2 is easy to calculate once you have SS Between.

4. Spreadsheet Concepts Revisited
There's a conceptual difference between what you do by hand, and how a spreadsheet operates. When you round off then you end up using those rounded-off-numbers in subsequent calculations. In this way it's easy for hand calculations (even if done correctly) to vary a small amount from the actual correct answer. (Of course if your calculations vary a large amount then something went askew!) However, spreadsheets work differently. In essence, spreadsheets always use the full number in all calculations. However, with a spreadsheet you can choose to have only part of the full number (e.g. two decimal places) displayed on the screen. So with spreadsheets you get the best of both worlds: all calculations done with the full number, but your eyes only need to look at the nicely formatted two-decimal-place rounded off number.

Surveys Open

The five group surveys are now open to be completed. You need to complete all 5 by September 24th at midnight.

It's probably easiest to answer all 5 at the same time. There will be some repetitious questions, but the data ends up going to different groups so please be understanding.

I have erased all submittals posted before today. There have been various small tweaks made to the surveys and they simply weren't ready for real submittals until this morning.

I have linked the five surveys. That means when you successfully complete Survey 1 you'll be taken to Survey 2 and so on. After completing Survey 5 you'll be taken to a general confirmation notice page. In total you can probably respond to all 5 surveys in less than 5 minutes. What a deal!

Please be honest when you are responding. I won't know the names of individual respondents, but I will have running counts of how many people from a few different courses have responded.

survey one link

Class List

I have created a class list form. To fill out the form use the link below. To see the results of the form, click on the brand new class list subpage link just above.

class list form link

Due Soon Assignments

There are lots of small assignments to complete before our next class. Let me briefly go over each type in turn.

Class List
I've posted a form for each student to complete so we can create a class list on the website. This will take you less than a minute. Please complete by this Friday.

Spreadsheet
Each person needs to submit their spreadsheet by September 22nd. This version of the spreadsheet needs to include your Cohen's d calculations.

Dig and Problem Set
Per usual Knowledge Dig 4 comments/questions and Problem Set 5 are due by midnight of the Wednesday just before the next teaching weekend (Sept 23).

Group Surveys
I've received surveys from 4 out of the 5 groups. I've also sent out clarification questions to a couple of groups. Once all the surveys are submitted and my questions resolved, then they will be posted to the website and opened for submittals. Each of you will need to complete each survey (even if you were in the creation group). However, each survey should be very easy and quick to complete. I hope to have all of this posted by Wednesday.

Session 3 Update

I have posted the live audio recording from yesterday's class at the Effect Size learning page.

effect size page link

How Google Saved a School

I had this posted at the Home page last week, but I'm cleaning up things and reposting here. Some of you may not have seen this short video clip yet. Very little to do with statistics, but quite interesting and they touch on the role Google Docs can play within a public school environment.

Effect Size Calculations Galore

I've just posted a new download package titled Effect Size Revisited. It includes answers to your problem set questions and much more. You don't need to download right now, but if you want to find out more head on over to the Session 3 learning page.

effect size learning page link

Laptops & Headphones

Recently someone asked if they should bring their laptop and headphones to every class meeting. The realistic answer is: probably.

Here's the bottom line: At almost every class session we'll view a spreadsheet construction movie and you'll be provided some time to work on your own spreadsheets. Some of you may want to review part of the movie on your own during this time—and thus headphones are needed. Most of you will want to do spreadsheet construction work on your own computer—and thus a laptop is needed.

All that said, if you want to buddy up with someone in class so you share a laptop and headphones then that's fine. It will mean you'll need to add to your own spreadsheet later at home, but that's not a real problem and in fact might be beneficial for learning the material well.

Put differently, if you want to work with at stats buddy then only one of you need to bring a laptop/headphones combo. If you'd prefer to work on your own then, well, bring your own gear.

Session 4 Materials Ready

All of the learning materials for Session 4 on ANOVA (or Analysis of Variance) are ready to download. No new resources have been posted, but the page itself has been updated so it's clearer which items are required versus those that are optional. Make sure you can download these items before this upcoming Saturday class. If you experience problems, then let me know. I'll bring a USB flash drive that you can use to transfer the materials to your computer in class.

session 4 page link

Effect Size Movie Draft

I'm working on creating a movie about calculation effect size using Cohen's d. If you are interested you can download the last 9 minutes (of the 21 minute movie) below. This is a draft version so I may tweak some settings. The final version will contain 3 case studies plus supplementary handouts (such as the PDF of the article this movie refers to). At any rate, some of you may benefit from seeing this preview of the upcoming movie that we'll all view together in class.

effect size partial movie download

Home Page Updates

There have been two recent updates to the Home page. So, if you automatically come to this News page first, then let me tell you why you may want to check out the Home page:

PBS Movie
I've added a 7 minute movie made by Frontlines at PBS titled, "How Google Saved a School." Important for learning statistics? No. Perhaps useful to see how one NYC school is starting to incorporate technology? Yes. And their choice of software is Google Docs, the same suite of software I use for creating surveys and collecting data in this class.

Disqus Personalized
Some of you have still not personalized your Disqus account with an intuitive display name and an avatar. Instead of a movie I've posted a pop-up image gallery that shows you how to do these changes in 5 easy steps. Check it out!

Statistics Consulting

There are two sources of statistics consulting help for this course. First, as all of you are aware, Raylene Potter serves as the official course statistics consultant. Most of you met her through the Technology Workshops given over the first two teaching weekends. Raylene previously wrote:

My planned onsite office hours will be from 5:15 - 6:15 pm, every teaching weekend Saturday, in your Applied Stats classroom. I also have scheduled phone-in or online office hours from 5:00 - 7:00 pm every Friday. Please feel free to call me or email me at any time. I will try to respond to messages within a reasonable timeframe.

My cell phone is: (831) 334 - 7438

The best email address to use is: raylenepotter@hotmail.com

Second, in addition to Raylene, if you live near USF then you may want to take advantage of our wonderful Learning & Writing Center. They offer specific help for graduate students in APA-style writing and statistics.

To learn more about their services you can download an eight minute interview conducted with Dr. Charlene Lobo-Soriano, Director of the Learning and Writing Center. Charlene addresses three key issues: (1) what services the Learning and Writing Center offers doctoral students, (2) what kinds of support it does not provide, and (3) what are the specific steps students need to take in order to set up either a writing or math consultation at the Center.

lobo-soriano interview download

You can visit the USF Learning & Writing Center webpage for more details. Alternatively you can phone the Center directly at: (415) 422-6713. The Center is located in Cowell Hall 227. No appointments can be made by leaving a phone message: instead you need to talk to a live person. Statistics consultations can be arranged on weekends with an advance appointment. You can also arrange statistics tutorials for other times also.