i repeat ... the r value shows the extent to which a straight line (in a 2 variable problem) can pass through a scatterplot and, be close TO the data points
in that sense, r is an index value for the extent to which a straight line MODEL fits the data ... knowing how the dots on the scatterplot got to be ... is totally outside the realm of what r can know At 10:06 AM 12/6/01 -0700, Alex Yu wrote: >Whether we can get causal inferences out of correlation and equations has >been a dispute between two camps: > >For causation: Clark Glymour (Philosopher), Pearl (Computer scientist), >James Woodward (Philosopher) > >Against: Nancy Cartwright (Economist and philosopher), David Freedman >(Mathematician) > >One comment fromm this list is about that causal inferences cannot be >drawn from non-experimental design. Clark Glymour asserts that using >Causal Markov condition and faithfulness assumption, we can make causal >interpretation to non-experimental data. > >**************************************************************************** >Chong-ho (Alex) Yu, Ph.D., MCSE, CNE, CCNA >Psychometrician and Data Analyst >Assessment, Research and Evaulation >Cisco Systems, Inc. >Email: [EMAIL PROTECTED] >URL:http://seamonkey.ed.asu.edu/~alex/ >**************************************************************************** > > > >================================================================= >Instructions for joining and leaving this list and remarks about >the problem of INAPPROPRIATE MESSAGES are available at > http://jse.stat.ncsu.edu/ >================================================================= _________________________________________________________ dennis roberts, educational psychology, penn state university 208 cedar, AC 8148632401, mailto:[EMAIL PROTECTED] http://roberts.ed.psu.edu/users/droberts/drober~1.htm ================================================================= Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =================================================================
