Question

Select three (3) ways, (from the list below) and EXPLAIN in each case how the experimenter can become the extraneous variable, (List of extraneous variables - experimenter characteristics and experimenter expectancies as it relates to Physiological ­experimenter characteristics including such aspects as age, sex, and race and Psychological ­experimenter attribute including such personality characteristics as hostility, anxiety, and introversion or extroversion.). Provide an explanation/justification for each way in no less than 200 words.

List and explain a method for controlling each of the three (3) listed ways the experimenter can affect a study? Provide an explanation/justification for each method in no less than 200 words.

Answer 1

Extraneous variables in psychological experiment are those variables which are not being investigated, but can influence the relationship between the Independent and Dependent variable, that are being studied. Experimenter's characteristics and expectancies about the outcome of the experiment can also become an extraneous variable, which can effect the validity of the experiment in process. For exapmle, let's say that an experiment is being conducted which examines the relationships between the background music and task performance of the students while doing mathematical question. The independent variable here would be the music which is being played in the background , and dependent variable would be the number of correct mathematical qestions solved per hour, by the students . Now, the experimenter's expectations from the students to how they 'should perform and behave' , is considered as extraneous variable. For example,if the control group is accurately answering the mathematical question more than the treatment group , the experimenter might unintentionally give clearer instructions on how to answer and encourage the treatment group to perform better. The experimenter's personality attributes like anxiety and temperament can also influence the dependent variable that is being studied. For example , if the experimenter is an introvert and anxiety prone , he/she would become anxious while conducting the experiment. Due to this, he might not be able to read the instructions to the students, explain the nature of the experiment and forget to ask for their consent, before starting the experiment.This would not only breach the ethical policies , but would also have an effect on the dependent variable.

There are many ways in which these errors can be avoided. Double-bind studies works on the principle of minimizing the experimenter's expectancies. For example, while conducting an experiment on the effects of drug X on the participants , neither the participants nor the experimenter should know which participant has received the drug or the placebo tablets.Since both participants and the experimenter is blind to the conditions, it minimizes the experimenter's expectancies from the participants on how they 'should behave or perform' in an experiment . Another method of controlling these errors is Pilot testing, where the experimenter conducts a small scale study to understand whether the participants have understood the instructions and if there is an misunderstanding among the participants about the instructions, whether it has been answered effectively by the experimenter or not.Standardized experimental procedures must be incorporated by the experimenter to avoid any error due to his/her own anxiety , hostility or any other personality traits.