Hawthorne Experiment

Part I - Illumination Experiments (1924-27)
These experiments were performed to find out the effect of different levels of illumination (lighting) on productivity of labour. The brightness of the light was increased and decreased to find out the effect on the productivity of the test group. Surprisingly, the productivity increased even when the level of illumination was decreased. It was concluded that factors other than light were also important.

Part II - Relay Assembly Test Room Study (1927-1929)
Under these test two small groups of six female telephone relay assemblers were selected. Each group was kept in separate rooms. From time to time, changes were made in working hours, rest periods, lunch breaks, etc. They were allowed to choose their own rest periods and to give suggestions. Output increased in both the control rooms. It was concluded that social relationship among workers, participation in decision-making, etc. had a greater effect on productivity than working conditions.

Part III - Mass Interviewing Programme (1928-1930)
21,000 employees were interviewed over a period of three years to find out reasons for increased productivity. It was concluded that productivity can be increased if workers are allowed to talk freely about matters that are important to them.

Part IV - Bank Wiring Observation Room Experiment (1932)
A group of 14 male workers in the bank wiring room were placed under observation for six months. A worker's pay depended on the performance of the group as a whole. The researchers thought that the efficient workers would put pressure on the less efficient workers to complete the work. However, it was found that the group established its own standards of output, and social pressure was used to achieve the standards of output