 The Feuerstein Program The Feuerstein Instrumental Enrichment IE program has been well-established as an effective intervention in other age groups and clinical situations. The methods creator, Professor Reuven Feuerstein, postulated that the thinking process is divided into three major phases - Input, Elaboration and Output - and that in each phase, different mental functions are at work. The quality of thinking depends upon the way the different functions are activated in each of the phases. The IE tools enable the correction or activation of cognitive deficiencies through use of targeted and focused mediation, which conserves and reinforces cognitive ability. 