A Followup question on Mlucas...

[cheesehead]

An apology and clarification:

Originally Posted by cheesehead

I think you are failing to distinguish between a priori probability and a posteriori probability ...

Dr. Silverman,

It occurs to me that my posting #32 came out looking more like I'm trying to teach you the distinction between priori and posteriori than I had intended. I apologize for that.

What I had originally intended was to point out to you just that I thought that novice posters were focusing more on a priori probabilities than you were, then to append my explanation of the distinctions, addressed to the possibly-novice reader.

I intended to use quotations from your posting as "paragraph headers" to show the latter audience where the priori/posteriori distinction mattered. However, during my composition I failed to keep that division clearly in mind, and wound up directing my whole message to you. I apologize for my carelessness and failure to focus there.

- - - -

(Also, I apologize to my memory of the late Doris Niles, my wonderful high school speech teacher who impressed me with the importance of defining one's audience in a way that had never "clicked" in my English classes.)

[ewmayer]

Uh-oh ... this is starting to look worryingly like the "Thoughts on President Bush's January 10 speech about Iraq" thread in the Soap Box...

[m_f_h]

In spite of Wunderdoktor's comment...

Originally Posted by cheesehead

Some of you knowledgable folks have been indulging in the bad habit of attributing lesser intellect to those whom you do not understand. I suggest that if you "do not understand" someone, you need to remember that you may be part of the problem!
(...)
Well, that's convenient, isn't it? A quick, simple explanation ... gratifying ... almost ... instantly.
Avoids all that tedious analysis of whether "instant gratification" actually has anything to do with a novice's confusion between TF and LL, doesn't it? :-)
Why spend time figuring out a reason for a novice's error that is respectful of him/her (and, BTW, is a better fit to the observed facts)? So much easier to chime in with the "instant" answer.
If the reason for a novice's confusion isn't immediately obvious, it's the novice's fault, not ...

Dear cheesehead, (1) you seemed to have missed our investments to politely, patiently, and quite explicitely answering the initial question and explain what's going on during the iterations of an LL test.
(2) right from the beginning I "defended" the thesis that the question arises by comparing LL to TF (I don't think "confusion between LL and TF" is appropriate) or other methods of "progressively eliminating other possibilities".
(3) I DO try to understand my student's problems, and I got quite frustrated in searching the "problem of comprehension" always first on my side; making my explanations more and more simple, adding "worked out examples", putting on my website solutions of all exercices and exams, summary of lectures, "cheat sheets", etc etc etc.
Then, more and more, I realized that more I did, less they did : whenever a solution to an exercise was available, they would not try to figure it out; whenever a summary was available, they would not look at the "long version"; when I took the habit of summarizing the previous lecture at the beginning of the next one, they would never try to get it if they had missed it, and this would even conduct them to not looking at the past lectures, since the "instantly gratifying" summary was there for that purpose, which would in addition underline what was important and what "a waste of time".
Now I'm almost of the point of getting convinced that the pedagogical effect is somehow antiproportional to the well-organizedness of the lectures.
(Just in case, I insist on the fact I'm talking about teaching math at university, to students who are supposed to have deliberately chosen to study this (admittedly particular) subject, in favour of everything else.)

Y'all oughta be ashamed of yerselves.

Fortunately there's our perfect hero Robin "Cheesehead" Hood to save the poor and helpless erring in the dark forests of Mersennewood...

[masser]

Originally Posted by ewmayer

Uh-oh ... this is starting to look worryingly like the "Thoughts on President Bush's January 10 speech about Iraq" thread in the Soap Box...

GULP!

[cheesehead]

Originally Posted by m_f_h

In spite of Wunderdoktor's comment...

Dear cheesehead,

I apologize for having cluttered this thread.

Moderators, can you transfer my clutter to a Soap Box thread?

[ewmayer]

Originally Posted by cheesehead

I apologize for having cluttered this thread.

Moderators, can you transfer my clutter to a Soap Box thread?

Don't sweat it, dear Cheesums - let's just stay on-topic and try to refrain from excessive post-posting post-dissection, 'kay?

[cheesehead]

Originally Posted by ewmayer

let's just stay on-topic

Ernst,

I am preparing to post a detailed reply to m_f_h's post #36. It will be about as on-topic, or not, as my #33. I expect my next reply to motivate others to reply, in turn.

I don't know your evaluation of the on-topicness or post-postingness of #33 or #36, but there's going to be more of it. So, do you want that here ... or in Soap Box?

[ewmayer]

Go for it, Cheesehead - we're pretty lenient when it comes to on-topic-ness around here.

Well, except maybe in the official "The Immortal Poetry of Donald Rumsfeld" thread...

[m_f_h]

Trying to summarize the main ideas of this thread:

1. The answer to the original question is now clear, and could have been found in a few minutes by the questionsetter by googling, following the "Math" link on any of mersenne.org pages, or reading http://mathworld.wolfram.com/Lucas-LehmerTest.html (although that starts with a defining recurrence equation written (mod Mp) - don't know if this makes sense if mod is not seen as operator and S_n not as an element of Z/(Mp)...).
2. There was some discussion about "the probability of a given number (Mp) being prime" ; I think here also the different meanings of this statement are clear (needless to say that since R.D.Silverman has probably published more papers on the subject than all other participants together on whatsoever topic, no need to try to explain it to him...)
3. There's starting an "education" sub-thread that could be moved wherever else ("Education" channel, soap box,...) - but we won't solve such fundamental worldwide problems on mersenneforum.org,anyway...

The most positive thing I will retain from this thread is the "big flower" analogy (in spite of a light flaw regarding the residue)... we wouldn't have had that if moderators would redirect initial questions of that kind directly to the "STICKY - README FIRST - WHAT'S HAPPENING DURING LL TEST" threads which certainly do exist; on the other hand this would have saved some time to those of us who have other things to do in life...