Demand Characteristics and Investigator Effects

What is the difference between demand characteristics and investigator effects?

Demand Characteristics = how participant influences results of experiment

Investigator Effects = how researcher influences results of experiment

What are demand characteristics?

Aspects of an experimental study that could give participants cues about the hypothesis.

What are examples of demand characteristics?

1. Leading questions

2. Repeated measures design

What are the consequences of demand characteristics?

-leads to participant reactivity

-lowers internal validity of study

What is participant reactivity?

When the participant alters their behaviour to support or hinder the aim of the research.

What are examples of participant reactivity?

1. Expectancy Effect

2. Social Desirability Effect

3. Hawthorne Effect

What is the Expectancy Effect

When a participant believes they’ve guessed the hypothesis of the experiment and changes their behaviour to support or hinder the aim.

What is the Social Desirability Effect?

Is when a participant acts in a way they believe will cause them to be viewed favourably.

What is the Hawthorne Effect?

Is when participants work harder than usual because they know they are being observed.

What are Investigator Effects?

How a researcher’s conscious or unconscious behaviours could give participants cues about the hypothesis.

Examples of Investigator Effects.

1. Direct Investigator Effects

2. Indirect Investigator Effects - loose procedure effect and investigator experimental design effect

What are Direct Investigator Effects?

Unconscious cues given by the researcher that encourages or discourages a certain response from participants, when interacting with the participants face-to-face.

What are Indirect Investigator Effects?

Unconscious cues given by the researcher that encourages or discourages a certain response from participants, without interacting with participants face-to-face.

What is the Loose Procedure Effect?

A type of indirect investigator effect, where the researcher has not standardised the study, leading to highly subjective results.

What is the Investigator Experimental Design Effect?

Is when the variables in a study have not been operationalised, leading to dependent variable being measured in a way that biases the results.

Consequences of Investigator Effects.

-invalid results

-researcher cannot conclude if results are due to bias or because of independent variable