Psychology Chapter 9 Flashcards

Dependent Variables

• Three types of dependent variables: self-report, behavioral, and physiological.

Selecting Research Participants

• Probability sampling: Essential for accurately describing a population, maintains randomness.
• Nonprobability sampling: Used for detecting causal relationships rather than describing populations; based on the researcher's judgment, not random.
• Sampling methods must ensure external validity for generalization to different populations.

Sample Size Determination

• Larger samples yield more accurate estimates of population values, enhancing reliability of results.

Manipulating the Independent Variable

• Operational definitions are crucial to convert conceptual variables into actionable instructions and stimuli for participants.
• Experimenters change conditions to observe potential causal effects.

Setting the Stage for Research

• Participants must receive essential information for informed consent, often including a rationale for the study; typically, the true hypothesis is not revealed.

Types of Manipulations

• Straightforward manipulations: Simple adjustments using written, verbal, or visual material. These include instructions and various stimulus presentations.
• Staged manipulations: Events are orchestrated to elicit psychological states or simulate real-world situations. Commonly used to provoke specific emotional responses from participants.

Strength of the Manipulation

• Strong manipulations create significant differences between participant groups, increasing the likelihood of detecting statistically significant effects.

Cost Considerations of Manipulation

• Financial limitations may affect the complexity of manipulations. Simpler presentations (written or verbal) are less costly than elaborate staged setups.
• Individual participant run scenarios require more time and resources compared to group settings.

Sensitivity of the Dependent Variable

• Sensitivity affected by ceiling and floor effects, impacting the ability to measure true differences.

Ceiling Effect

• Occurs when a dependent variable reaches maximum performance level, rendering the independent variable ineffective. For example, using overly easy math questions to assess intelligence can invalidate results.

Floor Effect

• Happens when a task's difficulty prevents participants from performing adequately, leading to an inability to detect differences. This can occur in sensitive measures, like suicide risk, where responses may be sparse.