Research Methods Flashcards: Controlling Participant Variables

A comprehensive set of vocabulary flashcards covering participant variables, sampling biases, and experimental design techniques from the lecture on research ethics and between-subjects vs. within-subjects designs.

Participant Variables

The personal characteristics that make one individual different from the next, also referred to as individual differences.

Selection Criteria

Definitions of participants in terms of the characteristics required for them to participate in the study, such as gender, age, or educational level.

Volunteer Bias

The bias that arises because a sample contains only those individuals who are willing to participate in the study.

Subject Sophistication

A bias that occurs when participants are knowledgeable about research methods, the topic under investigation, or the manipulations used.

$$N$$

The symbol representing the total number of participants in a study.

$$n$$

The symbol representing the number of participants observed in a single condition of an experiment.

Between-Subjects Design

A design in which a different group of participants is randomly selected for each condition of an independent variable.

Random Assignment

A method of controlling participant variables by randomly mixing them so that differences are balanced out across conditions.

Pretest

An assessment conducted prior to the study to measure potential participants on a variable to be controlled.

Collapsing

The process of combining scores from different amounts or categories of a variable to compute an overall mean.

Matched-Groups Design

A design where each participant in one condition is paired with a participant in every other condition based on one or more extraneous variables.

Limiting the Population

A technique to control a participant variable by keeping it constant through specific selection criteria, thereby eliminating its influence.

Within-Subjects Design

Also known as a repeated-measures design; a design in which the same participants are measured under all conditions of an independent variable.

Pretest-Posttest Design

A type of repeated-measures design where participants are measured on the dependent variable before and after they experience a treatment.

Subject History

Changes in scores influenced by the external life experiences participants have between measurements.

Subject Maturation

Changes in scores due to the internal development and growth of participants over time.

Subject Mortality

Also known as subject attrition; the loss of participants who drop out or refuse to continue before the study is completed.

Carry-Over Effects

A type of order effect where the experience of any one trial influences the scores on subsequent trials.

Response Sets

A type of order effect where a participant develops a habitual response for subsequent trials.

Complete Counterbalancing

A method to control order effects by testing different participants using all possible sequences of conditions.

Partial Counterbalancing

A method to control order effects by using only some of the possible sequences of conditions, often used to balance practice effects.

Randomization of Conditions

A method to control order effects by randomly creating different sequences under which different participants are tested.

Blocking Trials

The procedure of having participants complete all trials in one condition as a single group before moving to the next condition.

Nonsymmetrical Carry-Over Effects

Occur when the carry-over effects from one order of conditions do not balance out those of another order, making counterbalancing ineffective.