1. INTRODUCTION

2. THE SEYFERT GALAXIES OF THE 12 μm GALAXY SAMPLE

3. OBSERVATIONS AND DATA REDUCTION

4. OBSERVATIONAL RESULTS
4.1. H₂ excitation diagrams: H₂ temperatures and masses
4.2. Source extendedness

5. AGN DIAGNOSTIC DIAGRAMS: DATA AND MODELS
5.1. Line ratios versus PAH equivalent widths
5.2. Line ratios as density indicators
5.3. Ionization Diagrams
5.4. Line Equivalent Width Diagnostics
5.5. The AGN and starburst contribution to the 19 μm flux
5.6. Line equivalent widths for the different AGN types

6. [NEV] AS INDICATOR OF AGN ACTIVITY

7. AGN STATISTICS
7.1. Average Spectra for each class
7.2. Line Luminosity Functions

8. THE ACCRETION POWER IN THE LOCAL UNIVERSE

9. DISCUSSION AND CONCLUSIONS