Assesses a self-reward contracting procedure intended to facilitate completion of self-administered desensitization. Self-referred snake phobics received either (a) self-administered desensitization; (b) self-administered desensitization with self-reward contracting; or (c) a self-administered placebo with self-reward contracting. Results show the self-reward procedure significantly impaired the amount of time subjects devoted to self-instructional manuals. (Author)