 However, the ASQ has been criticized, with some researchers preferring to use a technique called Content Analysis of Verbatim Explanation (CAVE) in which an individual's ordinary writings are analyzed to assess whether s/he is vulnerable to the depressive attributional style.The key advantage of using content analysis is its non-invasive nature, in contrast to collecting survey answers or simulating social experiences.The concept of learned helplessness emerged from animal research in which psychologists Martin Seligman and Steven F. Maier discovered that dogs classically conditioned to an electrical shock which they could not escape, subsequently failed to attempt to escape an avoidable shock in a similar situation.