CHAPTER 8: SOLVING PROBLEMS: CONTROLLING EXTRANEOUS VARIABLES

Physical Variable

Aspects of testing conditions that need to be controlled. Example, day of the week, experimental room, and lighting.

Elimination

removing extraneous physical variables from the experimental situation

Constancy of Conditions

controls extraneous physical variables by keeping all aspects of the treatment conditions identical, except for the independent variable

Balancing

controls extraneous physical variables by equally distributing their effects across treatment conditions.

Social Variables

qualities of the relationships between subjects and experimenters that can influence results.

Demand Characteristics

aspects of the experimental situation that demand people to behave in a particular way.

Experimenter Bias

Happens when experimenter give the subjects cues that tell them how the experimenter would like them to respond.

Single-blind Experiment

A way to control demand characteristic, it is an experiment in which subjects do not know what treatment condition they are in.

Placebo Effect

when a subject receives an inert treatment and improves because of positive expectancies.

Covery Story

another alternative for controlling demand characteristics which is a plausible but false explanation for the procedures used in the study. It is told to disguise the actual research hypothesis so that subjects will not guess what it is

Rosenthal Effect

the phenomenon in which experimenters treat subjects differently based on their expectations and their resulting actions influence subject performance

Double-blind Experiment

A way to control experimenter bias in which the subjects do not know which treatment they are receiving, and the experimenter does not know

Personality Variable

This is the characteristics that experimenter brings to the experimental setting that may affect the response of the subject.

Context Variables

those that come about from procedures created by the environment, or context, of the research setting