JP Guilford (1961) developed a model of intelligence in which he explained that every intellectual activity can be described in terms of three different basic dimensions, viz., operations- the act of thinking, contents- the terms in which we think like words, symbols, etc. and products- the ideas we develop.
He has proposed his tri-dimensional theory of intelligence represented by cubical model. This model is provided with 120 primary abilities, and is a combination of 4 contents, 5 operations and 6 products (4x5x6=120).
Guilford (1967) has expanded his cube-shaped model of intellect to include 150 factors, which includes 5 contents, 6 products and 5 operations (5x6x5=150).
This may be understood by studying this example: A child is asked to determine the day of the week on a particular date with the help of a calendar. The task involves operations like convergent thinking, memory and cognition.
In carrying out these operations, he has to make use of the contents. In this particular case, he will make use of semantics, i.e. reading and understanding of the printed words and figures indicating days and dates of a particular month in the calendar.
By carrying out mental operations with the help of the contents he will finally arrive at the products. The day of the week to which the date in question refers represents the factor known as ‘relations’.