[Roger Hunter]

(02-08-2017, 08:41 PM)Skywise Wrote:

(02-08-2017, 05:59 PM)Duffy Wrote: I have to admit, that I have taken the time to try and understand the meaning of the word "chance".

Roger's use of the word 'chance' is from a statistics point of view. As well as several other words.

A simple example: coin tossing. It's pretty obvious that the odds of throwing heads is 50%. Now, if you throw 10 tosses (HTTHTHTHHT) with 5 heads and 5 tails, then that's chance.

What you are doing is obviously much more complicated. What roger is trying to do is figure out what the chance odds are of your crosses  correlating* with earthquakes. For example, you have 20 crosses, and 15 of them end up with quakes. That's 75% percent of them. But what were the chance odds anyway? If the chance odds ARE 75% then you are doing no better than chance, no better than random guessing, If you do better than chance, then that indicates 'significance'.

Significance also has a meaning in statistics. It's basically a measure of HOW much away from chance something is. This can get quite complicated and is based on things called distributions. Even if you got 90% of your crosses right given a chance of 75%, depending on the distribution curve of a random test, the significance may be high, or low.

By way of comparison, you wouldn't expect 10 coin tosses to ALWAYS have exactly 5 heads and 5 tails. Sometimes you get more of one than the other. 6 heads out of 10 coin tosses is better than chance, but not necessarily significant. It depends on the distribution of the results of many sets of ten coin toss sessions. This is something you can easily try yourself. Do 10 coin flips and record the number of heads. Then do ten more. Do this for at least 10 sets (total 100 coin tosses). Make a chart tallying how many times you get a particular number of heads, that is how many times did you get 0, or 1, or 2, etc, on up to 10. Then graph the results to see the distribution curve. The more sets, the smoother the curve. In this well known example you should get what is called a gaussian or normal distribution. You may have heard it called a bell curve.

*And for more definitions, correlation here means coincide. Science has a saying, though, that "correlation does not equal causation". Just because something correlates doesn't mean one causes the other or has any relationship to it. To drive that point home, check out the Spurious Correlations website - http://www.tylervigen.com/spurious-correlations. But finding correlations is an important first step in scientific progress.

Granted, statistics is not an easily understood subject. But it is such an important tool in the science tool box that its understanding is necessary.

Moving on, it is my observation that there's been a lot of miscommunication. You guys just aren't speaking the same language. I have to admit, I'm having a little trouble totally understanding your method. It happens. Sometimes a thing needs to be explained many different ways until it is comprehended. I've had to do that myself explaining things to others.

I encourage continuing the discussion in spite of these difficulties. I feel that in the end we will all learn something new. Duffy, you will certainly gain a better understanding of science, scientific methods and thinking, and statistics. Roger, I, and others will learn about new ideas in quake prediction (successful or not) and strengthen our knowledge and skills in studying and analyzing quake correlations. Even if your method turns out to be chance and have nothing to do with quakes, it's still important information. Science is built as much on what doesn't work than what does. Perhaps even more so.

I also encourage this discussion if for no other reason than how it is being carried out. It is civilized and constructive. This is how these discussions should be carried out and it is refreshing after years of previously hostile and adversarial discussions in the past.

Brian

Brian;

Thank you for a well thought out presentation of the situation. I'm not good at it, partly because my two fingers get tired. I will add that any result from coin tossing is chance whether 1 head in 10, 5 in 10 or even 10 in 10.
They all have different probabilities.

One of my motives in continuing this project is the hope of finding something that works but has been overlooked by the standard professional groups as too improbable to bother with.

So far all I've done is show they are right.

Roger