Originally Posted by
User Name
Apologies. We actually agree. I made the mistake of making a cup of tea in the middle of typing that!
^ (actually I did wonder as I agreed with your explanation, just not with your mistyped conclusion!
) Hope you enjoyed the tea though!!
Originally Posted by
muishkin
Under the pre-choice, assume the same distribution of meal loads, the probability of not getting your first choice are still the same
No actually, that probability of someone not getting their first choice will increase. The key is that not getting your first choice is not random error but sampling error, ie BA actually know what proportion of people tend to choose the beef, chicken, etc dishes and organise loads accordingly (they don't just take, say, 5 of each, but maybe 7 beef, 4 chicken, 2 salads, etc).
If all BA F customers were flying on one gigantic first class flight at the same time, BA's prediction would thus be extremely accurate and the proportion not getting their choice would be extremely low. However, as you reduce the sample size (which is what you do when most people have chosen their main through pre-order and you only cater for the rest), sampling error increases and so does the 'risk' that the sample will not be representative of the whole will increase accordingly.