GROUP DIFFERENCES

Ditto about pasting the table in my reloading room. Thanks Joe.

This is not a criticism of Joe's contribution but unfortunately it is often impractical to achieve a 95% confidence level in many kinds of decisions including deciding what load is best by shooting groups. Very few of us are going to shoot 20 5-shot groups of each load to decide which load is better when the difference in average group size is 10%. If we do shoot that many groups for one decision we won't have time to test for many other loads and maybe miss something better.  That would be counterproductive so we have to make decisions with less than 95% confidence levels.  That is OK we do it all the time for other decisions.

We seldom have the luxury of having a 95% confidence level for life decisions about things much more important that which load is best (to change jobs, to continue our education, get married, invest in which stock etc.).  The confidence level must be much less for these decisions (50% of marriages fail, an investor would soon be rich if he guessed which way a stock was going to move even 70% of the time and few are.)

It seems to me that what we need to offer us practical support for decision making is a table like Joe's above but based on a confidence level of 60 or maybe 80% it would require a number of groups that we might actually fire and being right most of the time wouldn't be bad. Something to think about.

John