This book presents an approach to quantifying consciousness and its various states. It represents over ten years of work in developing, test ing, and researching the use of relatively simple self-report question naires in the retrospective assessment of subjective or phenomenologi cal experience. While the simplicity of the method allows for subjective experience to be reliably and validly assessed across various short stim ulus conditions, the flexibility of the approach allows the cognitive psy chologist, consciousness researcher, and mental health professional to quantify and statistically assess the phenomenological variables associ ated with various stimulus conditions, altered-state induction tech niques, and clinical procedures. The methodology allows the cognitive psychologist and mental health professional to comprehensively quantify the structures and pat terns of subjective experience dealing with imagery, attention, affect, volitional control, internal dialogue, and so forth to determine how these phenomenological structures might covary during such stimulus conditions as free association, a sexual fantasy, creative problem solving, or a panic attack. It allows for various phenomenological pro cesses to be reported, quantified, and statistically assessed in a rather comprehensive fashion that should help shed greater understanding on the nature of mind or consciousness.