What is the problem?

The experimental method tries to abstract certain variables from complicated situations in nature, and reproduce parts of them in the lab in order to determine the effect of certain variables. This allows for generalization from information obtained in the lab back to the original situation.

Subjects being observed are usually viewed as passive responders instead of active participants. Additionally, experimental stimuli tend to be defined in terms of what is done to the subject, not how they react (limited dynamism). These factors combined lead to issues in reproducibility and ecological validity, which are necessary for meaningful experimentation.

What are demand characteristics?

A participant actively wants to contribute to research and will react to ‘demand characteristics’. A participant’s behaviour in an experiment is determined by perceived demand characteristics of the setting as well as by experimental variables.

Demand characteristics are the total cues conveying a hypothesis to participants which determine their behaviour (rumours about experiment, explicit/implicit information given during the experiment, laboratory setting, views based on previous knowledge and experience of participant etc.). the perceived demand characteristics in any experiment can vary.

What factors affect a subject’s reaction to stimuli in an experimental setting?

• Motivation to comply with experimenter’s instructions.
• Perception of behaviour research.
• Nature of cues likely picked up etc.

It is proposed that these factors must be further elaborated and the parameters of an experimental setting should be more carefully defined so that sufficient controls can be designed to isolate the effects of the setting from the effects of the experimental variables.

In our culture the roles of subject and experimenter are well understood and carry well-defined mutual role expectations within an experimental setting:

• Subjects put themselves under experimenter’s control.
• Subjects tolerate boredom/discomfort if required.
• Shared assumption of the purpose justifies request for many things from a participant in an experiment.
• Effort and discomfort are justified by a higher purpose.

It is hard to design an experiment that tests the degree of social control in an experiment because of the already high degree of control in an experimental situation.

Why do people comply with such a wide range of instructions/requests? (motivational aspects)

• They want the experiment to succeed and be a ‘useful’ participant.
• They attribute meaning to their actions.
• They identify with scientific goals.
• Subjects are concerned with their performance: reinforcing self-image, concerned with the usefulness of their performance.
• Subjects will act in line with ‘being a good participant’ and in a way to validate the perceived/assumed hypothesis.

In what kind of contexts and circumstances do demand characteristics become significant in determining the behaviour of subjects in experimental situations?

• Demand characteristics can not be eliminated, but you can study their effect.
• Studies need to take the effects of demand characteristics into account.
• Response to demand characteristics is not just conscious compliance – perception of experimenter’s hypothesis tends to be a more accurate predictor of actual performance than a statement about what the participants think they have done on a task.
• The most powerful demand characteristics, in determining behaviour, convey the experiment’s purpose effectively, but not obviously. If the subject knows the experimenter’s expectations, there may be a tendency for biasing in the opposite direction.

What are experimental techniques to study demand characteristics?

1. Studying each participant’s perception of the experimental hypothesis. Determine how they correlate with observed behaviour.
2. Determine which demand characteristics are perceived, post-experimental inquiry – inquiry procedures required to not provide expectation cues.
   • Criticisms of this inquiry: (a) inquiry procedure is subject to demand characteristics and (b) participant’s won behaviour can influence their perception of the purpose of the study. So a correlation of the participant’s expectations vs. experimenter’s hypothesis may not have much to do with determining behaviour.
3. Pre-experimental inquiry (approximation, not proof) – show procedure, materials, requirements, then ask participant’s what the hypothesis is without them having done experimental tasks. Also ask how they would have asked it if they had been part of the experiment.
   • Leads to formulating possible hypotheses without knowing about their own reactions to testing.
   • Participant’s own behaviour in the experiment can’t influence their perception of the purpose of the study because they did not take part in it yet.
   • Participants of pre-experimental inquiry can’t take part in the actual experiment anymore, but must be drawn from the same population.
   • If subjects describe behaviour matching the one actually performed at testing, it becomes possible that demand characteristics are responsible for behaviour. It ispossible that demand characteristics, instead of experimental variables, could account for the behaviour of an experimental group.
4. Hold the demand characteristics constant and get rid of the experimental variable. Simulating participants: instructed to act as if exposed to experimental variable.
5. Blind design controls for experimenter bias is important, as experimenter bias will also influence the participant’s assumed hypothesis.

All these techniques depend on active cooperation of the control participants. This suggests that the subject does not just respond in these control situations but rather is required to actively solve a problem. We should view experiments as a special form of social interaction. It is suggested that control of demand characteristics could lead to greater replicability and generalizability of psychological experiments.

Summary and outlook

• Experiments as a special form of social interaction.
• Subject should be recognized as an active participant.
• Subject’s behaviour in an experiment is a function of the totality of the situation, including the experimental variables and demand characteristics.
• Control for demand characteristics is suggested to lead to higher replicability and ecological validity.
• Study and control of demand characteristics are not just a matter of good research technique; it is an empirical issue to figure out in what context they significantly influence participants’ experimental behaviour.