And all of this implies a newly minted coin. On Mar 2, 2015, at 8:29 AM, John Kulig <[email protected]> wrote:
> It's my understanding that the head side has just a touch more surface area > because of the beveled edge (i.e. they are not perfect rectangles viewed from > the side). That would have been a better way for me to say it (i.e. beveled > edge). Sorry for my poor choice of words > > https://www.cointalk.com/threads/pennies-beveled-edges.111533/ > > ========================== > John W. Kulig, Ph.D. > Professor of Psychology > Coordinator, Psychology Honors > Plymouth State University > Plymouth NH 03264 > ========================== > > From: "Jim Clark" <[email protected]> > To: "Teaching in the Psychological Sciences (TIPS)" > <[email protected]> > Sent: Monday, March 2, 2015 9:17:23 AM > Subject: RE: [tips] Are coin tosses random? > > > If the head side is larger (heavier?), shouldn’t it come up tails? > > Jim > > Jim Clark > Professor & Chair of Psychology > University of Winnipeg > 204-786-9757 > Room 4L41 (4th Floor Lockhart) > www.uwinnipeg.ca/~clark > > From: John Kulig [mailto:[email protected]] > Sent: Monday, March 02, 2015 8:10 AM > To: Teaching in the Psychological Sciences (TIPS) > Subject: Re: [tips] Are coin tosses random? > > As a practical demo of a related issue, stand a few pennies on their edge (I > would alternate which side heads is on) on a table and shake or tap the table > and most will come up heads due to the fact that the head side of a penny is > ever so slightly larger than the tail side, hence has a very slight > preexisting tilt (that's what I have read .. I have not microscopically > examined them). But I have done it with pennies and if done carefully it is > very easy to demonstrate p<.05 :-) a value very different that 50%. A > physicist friend once explained how coins spun have a bias (slight) for tails. > > And I have usually regarded random as ignorance ,,, > > ========================== > John W. Kulig, Ph.D. > Professor of Psychology > Coordinator, Psychology Honors > Plymouth State University > Plymouth NH 03264 > ========================== > > From: "Wuensch, Karl L" <[email protected]> > To: "Teaching in the Psychological Sciences (TIPS)" > <[email protected]> > Sent: Sunday, March 1, 2015 11:01:21 PM > Subject: RE: [tips] Are coin tosses random? > > > > Philosophically this issue is more important. Does “random” just > mean ignorance of the mechanisms involved in determining the outcome (and > ignorance of the current states of those mechanisms). In the absence of > ignorance, would anything be random? > > Cheers, > <image001.jpg> > From: Jeffry Ricker, Ph.D. [mailto:[email protected]] > Sent: Sunday, March 01, 2015 3:37 PM > To: Teaching in the Psychological Sciences (TIPS) > Subject: Re: [tips] Are coin tosses random? > > > On Feb 28, 2015, at 6:28 PM, Jim Clark <[email protected]> wrote: > > One lesson I take away from Jeff`s original post (i.e., that even a simple > coin toss probability is a challenge to determine) is that we should not > worry too much by such minutia as whether all the abstract assumptions for > statistical tests are met. The real world is so messy that such contributions > to the correctness of our conclusions are probably minimal and in an > uncertain direction. > > Yes, that's an excellent point. I also was thinking about several other > issues that these studies might help to clarify for students. > > One is the issue of internal versus external validity (and yes, ecological > validity also could be mentioned, although that isn't what concerns me with > coin tossing). > > Based on what I was able to understand of their conclusions, both groups of > researchers seemed to be stating that their findings had high internal > validity, but they didn't think they would generalize to the types of > situations in which coins typically are tossed. > > I thought this would be an easy–to–understand example to use when I discuss > validity—as long as I leave the math out!!! > > Best, > > > -- > --------------------------------------------------------------------------------- > Jeffry Ricker, Ph.D. > Professor of Psychology Paul Brandon Emeritus Professor of Psychology Minnesota State University, Mankato [email protected] --- You are currently subscribed to tips as: [email protected]. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=42419 or send a blank email to leave-42419-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
