Hawthorne Effect

research-methodology

The Hawthorne effect refers to the phenomenon whereby participants alter their behaviour because they know they are being studied, not because of the experimental treatment itself. Any observed improvement may reflect the novelty of participation, increased attention, or awareness of being observed rather than the independent variable.

Origin

The term derives from a series of studies conducted at the Western Electric Company's Hawthorne Works in Cicero, Illinois (1924-1933). Researchers (including Elton Mayo) manipulated working conditions — lighting, rest periods, hours — and found that productivity improved regardless of the specific change. The explanation offered was that workers performed better because they were receiving attention and knew they were being observed. J.R.P. French (1953) coined the term "Hawthorne effect" to describe this phenomenon.

The original studies have been heavily criticised: Levitt & List (2011) re-analysed the data and found that the supposedly dramatic patterns were overstated. Nevertheless, the concept remains a standard validity threat in experimental research.

In Classroom Research

The Hawthorne effect is a significant confound in SLA classroom studies:

Treatment group novelty — a class receiving a new teaching method may improve simply because the method is different, not because it is better
Observer presence — students and teachers may behave differently when being recorded or observed (overlaps with Observer's Paradox)
Participation awareness — knowing they are in a study may increase learner motivation and effort
Teacher enthusiasm — teachers delivering a new treatment are often more engaged than those teaching as usual, confounding the treatment effect with teacher effect

Mitigating the Hawthorne Effect

Active comparison groups — instead of treatment vs no treatment, compare two alternative treatments so both groups experience novelty
Longer studies — novelty effects diminish over time; initial Hawthorne gains may wash out in delayed post-tests
Blind/double-blind procedures — where feasible, participants and/or teachers are unaware of which condition is the treatment
Baseline observation periods — allow participants to habituate to being observed before data collection begins
Comparison of multiple post-tests — if immediate gains disappear at delayed post-test, the Hawthorne effect is a plausible explanation

Relationship to Other Threats

The Hawthorne effect overlaps with several Internal Validity threats: it resembles the testing effect (awareness changes behaviour), novelty effect (new methods seem exciting), and the Observer's Paradox (observation changes the phenomenon). Distinguishing between these requires careful design and transparent discussion.

Key References

Mayo (1933) — The Human Problems of an Industrial Civilization
French (1953) — coined the term in Experiments in field settings
Levitt & List (2011) — re-analysis of original Hawthorne data
Cook & Campbell (1979) — Hawthorne effect as a validity threat