Meanings of "1" on arrows on Confirmatory Factor Analysis diagram I am just a novice in factor analysis.
I am writing some presentation about factor analysis and I am mainly reading about exploratory factor analysis. 
Both EFA and CFA have diagrams. For EFA usually factor loadings are seen on the arrows. However, for CFA usually there are some "1" on some arrows, but not all. As I am a novice in this, I do not really understand yet what those mean.
Can you give me some clues? 
For example, see here page 174, there is a picture :
http://psychology.concordia.ca/fac/kline/Library/k13b.pdf
 A: The "1" means that the coefficient for that particular path has been set 
(fixed) to 1, as mentioned by Peter Flom. The diagram you refer to is reproduced here:

In order for a latent variable to have a scale either its variance must be fixed (often to 1), or a path to one of it's indicators must be fixed (usually to 1), as in this case. The same applies for the errors - although it would be possible to fix the error variances instead of their paths, it is usually of interest to estimate the error variances directly, so you hardly ever see models where error variances are fixed instead of their paths. Also, it is worth noting that in many books, papers and software packages, the 1s on the error paths are not usually shown.
A: A "1" on diagrams like this usually means that the coefficient has been set to 1 by the person doing the analysis. Such settings are often necessary to allow model identification. 
A: There is a complete explanation p176: http://psychology.concordia.ca/fac/kline/Library/k13b.pdf
