1. A computer-implemented method of measuring speech for stress, fatigue and uncertainty, by a user of a computer system, comprising: providing a speech analysis device into which a user is directed by a computer system, to speak random text retrieved from a database and shown on a computer display; obtaining user-specific identification related to user speech, which is used in conjunction with identification of said user, to provide identification and authentication data of said user; providing a questionnaire to said user, to obtain data to establish a user-specific profile, and storing the provided data in said database; providing targeted speech to said user on a computer display, as a series of randomly selected text strings retrieved from said database, for the user to speak into said speech analysis device for speech analysis identification and authentication, and after validating of said user, storing said targeted speech data in said database for analysis; and obtaining intermittent stress measurements from said user during a task, through real-time speech analysis using targeted speech; wherein after completion of said speech analysis for identification and authentication of said user, said speech analysis identifies fluctuations in stress measures caused by stress, fatigue, and uncertainty of said user; and calculating a stress score for said user based upon said speech analysis.