The authors have developed an evaluation tool of intellectual productivity based on a concept of work concentration.
The tool consists of a cognitive task which is given to office workers and an analysis subsystem which analyzes the results of task and calculates CTR(Concentration Time Ratio) as an index of intellectual productivity.
In addition, a subject experiment was conducted in which the illumination conditions of office room were changed.
As the result, it was found that the index was not affected by learning effect and the difference of intellectual productivity by changing the illumination conditions could be evaluated quantitatively with the index.