Lesson C: The Basics of Experimentation

Independent Variable

It is the variable (antecedent condition) an experimenter intentionally manipulates

Levels

The ______ of an independent variable are the values of the IV created by the experimenter

True

An experiment requires at least two levels

True or False

Confounded

An experiment is _________ when the value of an extraneous variable systematically changes along with the independent variable

Dependent Variable

A ________ is the outcome measure the experimenter uses to assess the change in behavior produced by the independent variable

False

The independent variable depends on the value of the dependent variable

True or False

Operational Definition

An _______ specifies the exact meaning of a variable in an experiment by defining it in terms of observable operations, procedures, and measurements

Experimental Operational Definition

It specifies the exact procedure for creating values of the independent variable

Measured Operational Definition

It specifies the exact procedure for measuring the dependent variable

Nominal Scale

It assigns items to two or more distinct categories that can be named using a shared feature, but does not measure their magnitude

Ordinal Scale

It measures the magnitude of the dependent variable using ranks, but does not assign precise values

Ordinal Scale

This scale allows us to make statements about relative speed, but not precise speed, like a runner’s place in a marathon

Interval Scale

It measures the magnitude of the dependent variable suing equal intervals between values with no absolute zero point

Interval Scale

Degrees Celsius, Fahrenheit, and Sarnoff and Zimbardo’s 0-100 scale are just few of the examples of ________

Ratio Scale

It measures the magnitude of the dependent variable using equal intervals between values and an absolute zero

Ratio Scale

This scale allows us to state that 2 meters are twice as long as meter or even measure the distance in meters or time in seconds

Reliability

It refers to the consistency of experimental operational definitions and measured operational definitions

Reliability

A bathroom scale should display the same weight if you measure yourself three times in the same minute.

This is an example of?

Interrater Reliability

It is the degree to which observers agree in their measurement of the behavior

Interrater Reliability

An example of this is the degree to which three observers agree when scoring the same personal essays for optimism

Test-Retest Reliability

It focuses on the degree to which a person’s scores are consistent across two or more administrations of a measurement procedure

Test-Retest Reliability

An example of this is when scores are still highly correlated even after administering the particular test twice with a significant amount of duration gap

Inter-Item Reliability

It measures the degree to which different parts of an instrument (questionnaire or test) that are designed to measure the same variable achieve consistent results

Validity

It means the operational definition accurately manipulates the independent variable or measures the dependent variable

Face Validity

It is the degree to which the validity of a manipulation or measurement technique is self-evident

Face Validity

It is the least stringent form of validity

Face Validity

An example of this is when a researcher proposed/implemented to use a ruler to measure pupil size

Content Validity

It means how accurately a measurement procedure samples the content of the dependent variable

Predictive Validity

It means how accurately a measurement procedure predicts future performance

Construct Validity

It refers to how accurately an operational definition represents a construct

Internal Validity

It is the degree to which changes in the dependent variable across treatment conditions were due to the independent variable

Internal Validity

It establishes a cause-and-effect relationship between the independent and dependent variables

Confounding

It occurs when an extraneous variable systematically changes across the experimental conditions

Confounding

An example of ________ is when a study comparing the effects of meditation and prayer on blood pressure was not able to take into account that one group tend to physically exercise more

History Threat

It occurs when an event outside the experiment threatens internal validity by changing the dependent variable

History Threat

An example of _______ is when subjects in Group A were weighed before lunch while those in Group B were weighed after lunch. It is classified as ______ because external or outside events/factors have influenced the results of the dependent variable.

Maturation Threat

It is produced when physical or psychological changes in the subject threaten internal validity by changing the dependent variable

Maturation Threat

An example of _______ is when a study on boredom increases subject errors on a proofing task

Testing Threat

It occurs when prior exposure to a measurement procedure affects performance on this measurement during the experiment

Testing Threat

An example of _______ is when experimental subjects used a blood pressure cuff daily, while control subjects only used one during a pretest measurement

Instrumentation Threat

It is when changes in the measurement instrument or measuring procedure threatens internal validity

Instrumentation Threat

An example of _______ is if reaction time measurements became less accurate during the experimental than the control conditions

Statistical Regression Threat

It occurs when subjects are assigned to conditions on the basis of extreme scores, the measurement procedure is not completely reliable, and subjects are retested using the same procedure to measure change on the dependent variable.

Selection Threat

It occurs when individual differences are not balanced across treatment conditions by the assignment procedure

Selection Threat

An example of this is when even with random assignment, subjects in the experimental group were more extroverted than those in the control group

Subject Mortality Threat

It occurs when subjects drop out of experimental conditions at different rates

Selection Interactions

It occur when a selection threat combines with at least one other threat (history, maturation, statistical regression, subject mortality, or testing)

Method Section

The ________ of an APA research report describes the participants, apparatus or materials, and procedure of the experiment

Method Section

This provides the readers with sufficient detail (who, what, when, and how) to exactly replicate your study

Apparatus Section

The ________ of an APA research report is appropriate when the equipment used in a study was unique or specialized, or when we need to explain the capabilities of more common equipment so that the reader can better evaluate or replicate the experiment