title: Some Checking Procedures For Extension Analysis.
abstract: The extension procedure in common factor analysis is a two-stage least squares estimation procedure which may yield very poor fit to the extension variables and may yield Heywood cases. The three residual matrices, and three measures of goodness of fit that arise from the procedure should be examined in most applications, and the possible presence of Heywood variables in the extension set should be considered.
authors.forename: R P
authors.initials: RP
authors.lastname: McDonald