Field Experiments

Experiments look for the effect that manipulated variables (independent variables) have on measured variables (dependent variables), i.e. causal effects.

Field experiments are conducted in a natural setting (e.g. at a sports event or on public transport), as opposed to the artificial environment created in laboratory experiments. Some variables cannot be controlled due to the unpredictability of these real-life settings (e.g. the public interacting with participants), but an independent variable will still be altered for a dependent variable to be measured against.

Evaluation of field experiments:

Strengths

- Field experiments generally yield results with higher ecological validity than laboratory experiments, as the natural settings will relate to real life.

- Demand characteristics are less of an issue with field experiments than laboratory experiments (i.e. participants are less likely to adjust their natural behaviour according to their interpretation of the study’s purpose, as they might not know they are in a study).

Weaknesses

- Extraneous variables could confound results due to the reduced control experimenters have over them in non-artificial environments, which makes it difficult to find truly causal effects between independent and dependent variables.

- Ethical principles have to be considered, such as the lack of informed consent; if participants are not made aware of their participation in an experiment, privacy must be respected during observations and participants must be debriefed appropriately when observations come to an end.

- Precise replication of the natural environment of field experiments is understandably difficult, so they have poor reliability, unlike laboratory experiments where the exact conditions can be recreated.

- Field experiments are more susceptible to sample bias, as participants are often not randomly allocated to experimental conditions (i.e. participants’ groups are already pre-set rather than randomly assigned).