Robert MacG. Dawson pretty much said it - a statistical population is not always obvious.
I use the following with my students: Population: The set of all possible measurements under discussion; the part of the Universe you care about. By 'possible' we may mean a procedure which cannot in fact be repeated. Repeated sample selection, however, asks us to assume that the repeat samples are taken from the same defined population. "Same" here means 'no effective change in measured properties.' See how complex it gets in a hurry?!! :) R. MacG. pointed out that the population is the part of the Universe you may make inferences about. Usually you wish to estimate a future outcome (sales next month, % product pass inspection next shift), so it follows that most populations are infinite - incompletely measurable. Therefore, any sample you take will be (for these populations) an incomplete sample. Then the average of the sample, x-bar, estimates the mean of the population, mu, and the estimated standard deviation, s, estimates the (true) standard deviation, sigma. Clearly (I hope!) these entities are not identical, no matter how much instructors - including me - neglect the subtleties. Hope this helps a little at least, Jay Mel wrote: > Hi there, > > I am trying to understand the basics of statistics and was needing a brief > explanation of Population. To me this terms simply means the gathering of > data values and the "work" that is involved with this. Can someone please > correct me if I am wrong. > > Thanks in advance > Mel > > . > . > ================================================================= > Instructions for joining and leaving this list, remarks about the > problem of INAPPROPRIATE MESSAGES, and archives are available at: > . http://jse.stat.ncsu.edu/ . > ================================================================= -- Jay Warner Principal Scientist Warner Consulting, Inc. 4444 North Green Bay Road Racine, WI 53404-1216 USA Ph: (262) 634-9100 FAX: (262) 681-1133 email: [EMAIL PROTECTED] web: http://www.a2q.com The A2Q Method (tm) -- What do you want to improve today? . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
