IBM® SPSS® Amos™ 28
The Tucker-Lewis coefficient (
in the notation of Bollen, 1989b) was discussed by Bentler and Bonett (1980) in the context of analysis of moment structures, and is also known as the Bentler-Bonett non-normed fit index ( NNFI).
,
where 
and 
are the discrepancy and the degrees of freedom for the model being evaluated, and 
and 
are the discrepancy and the degrees of freedom for the baseline model.
The typical range for TLI lies between zero and one, but it is not limited to that range. TLI values close to 1 indicate a very good fit.
Use the \tli text macro to display TLI on a path diagram.
