The Elsmar Cove Forum Regression analysis with discrete dependent variable and continuous independent var.
 Forum User Name Keep Me Logged In Password
 Register Photo Albums Blogs FAQ Social Groups Calendar Search Today's Posts Mark Forums Read

 Elsmar Cove Forum Visitor Notice(s) It is the Memorial Day holiday weekend in the US so activity in the forum will be slow through the weekend. Since Memorial Day is observed on Monday 27 May this year, I expect activity here to be somewhat slow. Normal activity in the forum will start to pick up again next week. Please see the forum Calendar for more information on the holiday.Logged In Registered Members can click the red X to close this notice box.

 Elsmar Cove Forum Sidebar @import url(http://www.google.com/cse/api/branding.css); Custom Search Monitor the Elsmar Forum Monitor New Forum Posts Follow Marc & Elsmar Elsmar Cove Groups Sponsor Links Donate and \$ Contributor Forum Access Sponsored Links Courtesy Quick Links Links that Elsmar Cove visitors will find useful in your quest for knowledge: Howard'sInternational Quality Services Atul'sSymphony Technologies Marcelo Antunes'SQR Consulting Bob Doering'sCorrect SPC - Precision Machining NIST's Engineering Statistics Handbook IRCA - International Register of Certified Auditors SAE - Society of Automotive Engineers Quality Digest Portal IEST - Institute of Environmental Sciences and Technology ASQ - American Society for Quality

#9
14th June 2012, 09:51 AM
 blindfreak Getting Involved (6 to 9 Posts)   Registration Date: Jun 2012 Location: Germany Posts: 7 Thanks Given to Others: 11 Thanked 1 Time in 1 Post Karma Power: 4 Karma: 15
Re: Regression analysis with discrete dependent variable and continuous independent v

Using MiniTab, I calculated Spearman's rho and Pearson's r (you find the "How to" in Minitab support ID1198). I ran it with all my data sets and found both (rho and r) to be very similar. As Spearman's analysis only assumes a monotonic dependence, while Pearson's assumes a linear dependence I would conclude, that a linear model could be used (right?).
This is further supported by the fact, that both (rho and r) gave the same directional results as a linear regession model.
While Spearman's analysis only allows to analyse a single factor at a time, based on the findings described above, could I still apply a multifactorial linear regression model?

Again, many thanks!!!
Linus
 Thanks to blindfreak for your informative Post and/or Attachment!

#10
14th June 2012, 09:59 AM
 Barbara B Number Cruncher   Registration Date: May 2005 Location: Germany Posts: 390 Thanks Given to Others: 95 Thanked 270 Times in 173 Posts Karma Power: 79 Karma: 3799
Re: Regression analysis with discrete dependent variable and continuous independent v

Imho ordinal logistic regression is the correct approach if your response is a ranked variable (with or without non-equidistant ratings). is defined as a variable which has a ranking, but the distance between the ranks couldn't be quantified and aren't equal. On the Minitab help pages you'll find the following
Quote:
 Use ordinal logistic regression to perform logistic regression on an ordinal response variable. Ordinal variables are categorical variables that have three or more possible levels with a natural ordering, such as strongly disagree, disagree, neutral, agree, and strongly agree.
An ordinal regression analyzes which predictor has an effect on the ranking, e. g. if the amount of revenue has an impact on the students' attractivity ranking. Due to the 71 different ranks you got 70 different coefficients (1 level is used as reference level and 70 differences are calculated for the other 70 ranks) along with a test if this coefficient is different from the reference level (in this case p<0.05 if alpha=5%).

But the use of 71 different rankings will blur the results, so I would try to group the rankings, e. g.
• 1 - most attractive: rank 1-5
• 2 - very attractive: rank 6-10
• 3 - attractive: rank 11-20
• 4 - less atttractive: rank 21-30
• 5 - unattractive: rank 31-71

Barbara
 Thank You to Barbara B for your informative Post and/or Attachment!
#11
14th June 2012, 04:45 PM
 Miner Forum Moderator   Registration Date: Apr 2002 Location: Greater Milwaukee area, Wisconsin Posts: 3,110 Thanks Given to Others: 557 Thanked 1,719 Times in 1,104 Posts Blog Entries: 13 Karma Power: 390 Karma: 16643
Re: Regression analysis with discrete dependent variable and continuous independent v

Quote:
 In Reply to Parent Post by blindfreak Using MiniTab, I calculated Spearman's rho and Pearson's r (you find the "How to" in Minitab support ID1198).
Since you found this, I searched and discovered that Minitab has a hidden, experimental command for Rank Regression called RREGRESS (Minitab support ID 619). You cannot access it through the menu, but must enter it on the command line (Editor > Enable Commands).
Attached Thumbnails

__________________
"A fool can learn from his own experiences; the wise learn from the experience of others." - Democritus, 460-370 B.C.
 Thanks to Miner for your informative Post and/or Attachment!
#12
15th June 2012, 08:28 AM
 blindfreak Getting Involved (6 to 9 Posts)   Registration Date: Jun 2012 Location: Germany Posts: 7 Thanks Given to Others: 11 Thanked 1 Time in 1 Post Karma Power: 4 Karma: 15
Re: Regression analysis with discrete dependent variable and continuous independent v

@Miner: Wow! Amazing that you found that hidden command! Many thanks for your efforts!

I conducted the rank regression and got the following output:

Rank Regression: Ideal Employ versus ENVTL. IMPAC; ENVTL. MGMT.; ...
The regression equation is
Ideal Employer Rank = 31,1 + 0,0850 ENVTL. IMPACT - 0,201 ENVTL. MGMT. +
0,149 DISCLOSURE + 0,000009 Revenue \$ mio - 0,000171 Profit \$ mio

Coefficient Coefficient
Predictor Rank Least-sq Rank Least-sq
Constant 31,05 29,33 18,86 17,22
ENVTL. IMPACT 0,0850 0,1112 0,1990 0,1817
ENVTL. MGMT. -0,2007 -0,1842 0,2351 0,2147
DISCLOSURE 0,1492 0,1385 0,1426 0,1302
Revenue \$ mio 0,00000922 0,00000836 0,00004042 0,00003692
Profit \$ mio -0,0001714 -0,0001511 0,0005948 0,0005433
Hodges-Lehmann estimate of tau = 18,19 Least-squares S = %2

Unusual observations
Ideal
ENVTL. Employer
Observation IMPACT Rank Pseudo Fit SE Fit Residual
23 45,3 29,00 28,24 38,42 11,86 -9,42 X
51 48,4 44,00 45,79 40,13 11,05 3,87 X
59 63,8 50,00 51,78 32,56 12,56 17,44 X
X denotes an observation whose X value gives it large leverage.

My question: Is there any number or value that assesses the strength or confidence of the relationship (I am desperately looking for something like a p-value or adjusted R-square value)? In the end, I want to reject my H0 hypothesis and need the relevant information to accomplish that.

@ Barbara B: Thanks for the 'grouping hint'! I will definitiely try that approach. Many thanks for your efforts as well!
#13
15th June 2012, 12:27 PM
 Miner Forum Moderator   Registration Date: Apr 2002 Location: Greater Milwaukee area, Wisconsin Posts: 3,110 Thanks Given to Others: 557 Thanked 1,719 Times in 1,104 Posts Blog Entries: 13 Karma Power: 390 Karma: 16643
Re: Regression analysis with discrete dependent variable and continuous independent v

The Hodges-Lehmann estimate of tau is the number that you want. I am researching information on how to interpret it, but I can tell you that the lower this number is, the better.

The third number from the left in the coefficients table is the equivalent of the SE (standard error) in a least squares analysis. Again, the smaller the better.
__________________
"A fool can learn from his own experiences; the wise learn from the experience of others." - Democritus, 460-370 B.C.
 Thanks to Miner for your informative Post and/or Attachment!
#14
18th June 2012, 05:33 AM
 blindfreak Getting Involved (6 to 9 Posts)   Registration Date: Jun 2012 Location: Germany Posts: 7 Thanks Given to Others: 11 Thanked 1 Time in 1 Post Karma Power: 4 Karma: 15
Re: Regression analysis with discrete dependent variable and continuous independent v

I opened a new thread on the Hodges-Lehmann question because it is quite deviant from my original question.

Last edited by blindfreak; 18th June 2012 at 06:41 AM.

 The Elsmar Cove Forum Regression analysis with discrete dependent variable and continuous independent var.

 Bookmarks

 Visitors Currently Viewing this Thread: 1 (0 Registered Visitors (Members) and 1 Unregistered Guest Visitors)

 Forum Posting Settings You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules

 Similar Discussion Threads Discussion Thread Title Thread Starter Forum Replies Last Post or Poll Vote jayjo Using Minitab Software 7 22nd August 2012 05:18 AM MohammedT Using Minitab Software 7 27th September 2010 03:23 AM Wicked SPC Monitoring and Statistical Analysis Techniques 7 26th April 2010 10:11 AM Randy Definitions, Acronyms, Abbreviations and Interpretations 3 26th December 2006 06:41 PM Paul F. Jackson SPC Monitoring and Statistical Analysis Techniques 3 28th January 2004 04:06 PM

The time now is 07:58 AM. All times are GMT -4.