I'm trying to determine the LL of the null model for a HB run model. I understand from other posts that the model LL is determined by:

A) For each respondent, take the natural log of the RLH and multiply it by the number of tasks completed by that respondent: LN(RLH)*#Tasks. This gives you the LL per respondent.

B) Multiply that amount by the number of respondents, giving you the total LL across respondents.

However, I don't know how to determine the LL for the null model. I want to find this out to determine a McFadden's R^2.

Keith mentions in another post that Perct.cert is the same as McFadden's R^2 but with values in the. 5-.7 or higher range this would make the model fit extremely good as McFadden's R^2 in the range of .2-.4 represent values of extremely good fit. So I'm a little confused.

I'd love some direction here.

Jasha