Quasi-experimental Designs Overview

Questions and Answers

What is a one-group posttest-only design?

A design without a comparison group that has serious deficiencies in internal validity.

What is a one-group pretest-posttest design?

A design where participants are measured before and after manipulation to compute an index of change.

What are history effects in quasi-experimental designs?

Confounding events that occur at the same time as the experimental manipulation.

What are maturation effects?

Systematic changes that occur over time, such as becoming bored, fatigued, or wiser. Signup and view all the answers

What is instrument decay?

Changes in the measuring instrument over time. Signup and view all the answers

What is regression toward the mean?

The phenomenon where extreme scores tend to move closer to the mean upon retesting. Signup and view all the answers

What is a nonequivalent control group design?

A design that employs a separate control group, but the groups may not be equivalent. Signup and view all the answers

What are selection differences in a nonequivalent control group design?

Differences between the experimental and control groups that may become confounding variables. Signup and view all the answers

What is an interrupted time series design?

A design that examines a variable over an extended period both before and after a manipulation. Signup and view all the answers

What is the purpose of a control series design?

To improve the interrupted time series design by adding a control group. Signup and view all the answers

What is the cross-sectional method?

A method where individuals of different ages are studied at one point in time. Signup and view all the answers

What is the longitudinal method?

A method involving the observation of the same group of people over time. Signup and view all the answers

What is a cohort?

A group of people born at about the same time and exposed to similar societal events. Signup and view all the answers

What is the sequential method?

A method that combines cross-sectional and longitudinal techniques. Signup and view all the answers

What is replication in research?

The process of repeating a study to confirm findings and improve generalization. Signup and view all the answers

What is exact replication?

An attempt to replicate the exact procedures of a study. Signup and view all the answers

What is conceptual replication?

Replicating research findings using different procedures. Signup and view all the answers

What is a meta-analysis?

A statistical procedure that combines results from multiple studies. Signup and view all the answers

What is a third-variable problem?

A variable related to both the independent and dependent variables Signup and view all the answers

What is a confounding variable?

A third variable that can explain the relationship between two observed variables Signup and view all the answers

What are some disadvantages to experimental methods?

Artificiality of experiments, ethical and practical considerations, participant variables, description of behavior, successful predictions of future behavior. Signup and view all the answers

What are participant variables?

Characteristics of individuals such as age, gender, and personality. Signup and view all the answers

The __________ correlation coefficient assesses reliability of measures.

Pearson Signup and view all the answers

What does Test-Retest Reliability measure?

Correlation of scores at two different times to check reliability. Signup and view all the answers

What is internal consistency reliability?

Assessment of reliability using responses at one point in time, including split-half reliability and Cronbach's alpha. Signup and view all the answers

What are item-total correlations?

Examine the correlation of each item score with the total score based on all items. Signup and view all the answers

What is a response set?

A tendency to respond to questions from a particular perspective rather than based on the content of the questions. Signup and view all the answers

What should be avoided in survey questions to maintain simplicity?

Jargon and technical terms. Signup and view all the answers

What are double-barreled questions?

Questions that ask two things at once. Signup and view all the answers

What is a loaded question?

A question that leads people to respond in one way. Signup and view all the answers

What is negative wording in questions?

Phrasing questions with negatives that can confuse respondents. Signup and view all the answers

What does 'yea-saying' or 'nay-saying' refer to?

The tendency of a respondent to agree or disagree with all questions. Signup and view all the answers

What are closed-ended questions?

Questions with a limited number of response alternatives. Signup and view all the answers

What are open-ended questions?

Questions that allow respondents to answer freely. Signup and view all the answers

What is interviewer bias?

Bias that can occur due to the interviewer's influence on a respondent's answers. Signup and view all the answers

What is a panel study?

A study where the same people are surveyed at multiple points in time. Signup and view all the answers

What is the response rate in a survey?

The percentage of people who completed the survey. Signup and view all the answers

What is a posttest-only design?

A design where two equivalent groups are needed, the independent variable is introduced, and the effect is measured afterward. Signup and view all the answers

What are selection differences?

The condition where participants chosen for groups cannot systematically differ. Signup and view all the answers

What is a pretest-posttest design?

A design that includes a pretest before the experimental manipulation. Signup and view all the answers

What is an independent groups design?

A design where participants are randomly assigned to different conditions, participating in just one group. Signup and view all the answers

What is a repeated measures design?

A design where participants experience all conditions of the experiment. Signup and view all the answers

What is the order effect?

The impact that the sequence of treatments may have on the dependent variable. Signup and view all the answers

What is a practice effect?

An improvement in performance due to repeated practice. Signup and view all the answers

What is a fatigue effect?

A decline in performance as an individual becomes tired or distracted. Signup and view all the answers

What are time-related order effects?

Effects that occur as a result of a sequence of tasks over time. Signup and view all the answers

What is a contrast effect?

When the response to a second treatment is influenced by the first treatment. Signup and view all the answers

What does counterbalancing refer to?

Changing the order of conditions in a repeated measures design. Signup and view all the answers

What is a matched pairs design?

A design where participants are matched based on a characteristic before assignment to groups. Signup and view all the answers

What is a confederate in an experiment?

An individual who appears to be part of the study but is actually part of the manipulation. Signup and view all the answers

What are self-report measures?

Measures that capture attitudes, judgments, or preferences from participants. Signup and view all the answers

What are behavioral measures?

Direct observations of participants' behaviors. Signup and view all the answers

What are physiological measures?

Recordings of the body's responses. Signup and view all the answers

What are demand characteristics?

Features of an experiment that can inform participants about the study's purpose. Signup and view all the answers

What are filler items?

Unrelated items used to disguise the actual measure in a survey. Signup and view all the answers

What is a placebo group?

A group that receives an inert substance rather than the actual treatment. Signup and view all the answers

What is a single-blind experiment?

An experiment where the participant does not know whether they receive a placebo or the actual treatment. Signup and view all the answers

What is a double-blind experiment?

An experiment where both the participant and the experimenter are unaware of treatment assignments. Signup and view all the answers

What is a pilot study?

A trial run of the experiment with a small number of participants to test procedures. Signup and view all the answers

What is a manipulation check?

A measure to determine if the manipulation had the intended effect. Signup and view all the answers

What are factorial designs?

Designs that include more than one independent variable. Signup and view all the answers

What is a main effect in factorial designs?

The effect of an independent variable while ignoring other variables. Signup and view all the answers

What is an interaction in factorial designs?

When the effect of one independent variable depends on another variable's level. Signup and view all the answers

What is a moderator variable?

A variable that influences the relationship between two other variables. Signup and view all the answers

What are simple main effects?

Mean differences at each level of an independent variable analyzed when interactions are significant. Signup and view all the answers

What are single case experimental designs?

Designs to determine if a manipulation affects an individual participant over time. Signup and view all the answers

What is a baseline in single case designs?

The period where a participant's behavior is measured before the experimental manipulations. Signup and view all the answers

What is a reversal design?

A design that measures behavior during baseline, treatment, and a second baseline period. Signup and view all the answers

What is a multiple baseline design?

A design demonstrating treatment effectiveness when behavior changes only after manipulation across multiple settings. Signup and view all the answers

What is program evaluation?

Research aimed at assessing programs implemented to achieve positive effects on populations. Signup and view all the answers

What are quasi-experimental designs?

Designs that study effects in settings without full control features of true experiments. Signup and view all the answers

What is a one-group posttest-only design?

A design which lacks a control group and only measures the outcome after manipulation. Signup and view all the answers

Study Notes

Research Methods

Third-variable problem: An extraneous variable that can create a misleading relationship between the studied variables, providing alternative explanations for observed correlations.
Confounding variable: An uncontrolled third variable intertwining two variables, making it unclear which is influencing the outcome. Example: Income may confound exercise studies.
Disadvantages of experimental methods:
- Artificial nature of experiments may lack real-world applicability.
- Ethical and practical concerns can restrict research designs.
- Participant variables can introduce variability.
- Limited description of behavior possible in controlled settings.
- Difficulty in making accurate predictions about future behavior.
Participant variables: Individual characteristics (age, gender, nationality) that are non-experimental and measured rather than manipulated.
Pearson correlation coefficient: A statistical measure indicating the strength and direction of the relationship between two variables.
Test-Retest Reliability: Reliability assessed by correlating scores from the same test administered at two different times, although memory retention can skew results.
Internal Consistency Reliability: Evaluated by comparing scores from split halves of a test or using Cronbach's alpha to assess coherence among test items.
Item-total correlations: Measure the relationship between individual item scores and the total score to identify poorly correlating items for improved measure reliability.
Response set: A consistent tendency to approach survey questions from a specific perspective (e.g., social desirability) can bias results.

Survey Question Design

Simplicity: Survey questions should be simple and clear, avoiding jargon to ensure easy understanding and response.
Double-Barreled questions: Questions that ask about two aspects at once should be avoided to prevent confusion.
Loaded questions: These questions contain emotionally charged terms that may bias respondent answers, influencing conclusions.
Negative wording: Questions phrased negatively can confuse respondents, leading to potential inaccuracies in answers.
Yea-saying/Nay-saying: Respondents may agree or disagree consistently across questions, potentially misrepresenting their true opinions. This response set should be minimized through careful wording.
Closed-ended questions: These provide limited response options, making them easier to analyze and ensuring uniformity in answers.
Open-ended questions: Allow respondents to answer freely, offering depth but requiring more complex analysis and potentially unclear responses.
Interviewer bias: Interviewer characteristics and behaviors can inadvertently influence participant responses, affecting data reliability.

Research Design

Panel study: Involves surveying the same participants across multiple time points to assess changes and relationships between variables.
Response rate: Percentage of surveyed individuals who complete the survey; a low response rate can indicate biases affecting generalizability.
Posttest-only design: Involves obtaining two equivalent groups, manipulating the independent variable, and measuring the dependent variable's response.
Selection differences: Ensuring participants do not differ systematically across experimental conditions to maintain internal validity.
Pretest-posttest design: Measures participants before and after manipulation, verifying group equivalence initially.
Independent groups design: Random assignment of participants to groups so that each participant is assigned to one condition only.
Repeated measures design: Each participant experiences all conditions, allowing for powerful within-subject comparisons.
Order effect: The sequence of treatment presentations can influence results; strategies like counterbalancing are necessary to mitigate this.
Counterbalancing: Employs different orders of conditions in repeated measures designs to control for order effects.
Matched pairs design: Participants are paired based on shared characteristics to reduce variability and increase data sensitivity.
Confederate: An assistant in an experiment posing as a participant to create desired social conditions.

Measurement Types

Self-Report Measures: Utilized to gauge attitudes or judgments, reliant on participant honesty and accuracy.
Behavioral measures: Based on direct observations of behavior, allowing for objective data collection.
Physiological Measures: Document biological responses to gauge effects of manipulations.

Experimental Challenges

Demand characteristics: Features of an experiment that may reveal the study's purpose, potentially biasing participant responses.
Filler items: Used to obscure the dependent measure within a questionnaire to reduce demand characteristics.
Placebo group: Receives an inert treatment to isolate the effects of the actual treatment.
Single blind experiment: Participants are unaware of whether they receive a placebo or treatment, reducing bias.
Double-blind experiment: Both participants and experimenters are unaware of group assignments, controlling bias on both sides.
Pilot study: A preliminary trial to test the feasibility and clarity of procedures and measures before the main study.
Manipulation check: A method to ensure the independent variable is effectively applied, contributing to the study’s construct validity.

Advanced Research Designs

Factorial designs: Involve multiple independent variables assessed simultaneously, allowing for examination of interactions and main effects.
Interaction: Occurs when the effect of one independent variable depends on the level of another variable.
Moderator variable: Influences the strength or direction of the relationship between two other variables.
Single case experimental designs: Focus on an individual's behavior over time, comparing measures before and after a manipulation.
Baseline: Initial measurements gathered before introducing an experimental manipulation.
Reversal design: Analyzes behavioral changes by observing before and after manipulation, and again in the baseline phase.
Multiple Baseline Designs: Demonstrate effects of manipulation across multiple circumstances to establish treatment effectiveness.

Other Research Methodologies

Program evaluation: Research assessing the implementation and effectiveness of programs aimed at societal improvement.
Quasi-experimental designs: Allow for studying variable impacts without random assignment, but with challenges in drawing causal conclusions.
One-group posttest-only design: Lacks a control group, making causal inferences difficult.
One-Group Pretest-Posttest Design: Measures before and after a manipulation but susceptible to alternative explanation threats to validity.
History effects: Events overlapping with experimental manipulation can confound results, complicating interpretations.
Maturation effects: Systematic changes occurring naturally over time can distort results in research designs involving repeated measures.### Quasi-Experimental Designs
Changes not attributable to treatment may arise due to maturation effects.
Instrument decay occurs when measuring instruments change over time, affecting behavior measurement; this can happen due to observer skill level, fatigue, or altered standards.

Regression Toward the Mean

Regression toward the mean occurs when participants are initially selected for extreme scores; upon retesting, scores converge towards the average.

Nonequivalent Control Group Design

Utilizes a separate control group with non-equivalent participants; results can be confounded by selection differences.

Nonequivalent Control Group: Selection Differences

Differences between experimental and control groups may act as confounding variables, especially if groups are formed from existing natural groups.

Nonequivalent Control Group Pretest-Posttest Design

Enhancements to nonequivalent control group design include pretesting, although it remains non-randomized; pretest scores help assess group equivalence.

Interrupted Time Series Design

Analyzes a variable over time before and after a manipulation to observe its impact.

Control Series Design

An enhancement to the interrupted time series design, which incorporates a control group to strengthen validity.

Cross-Sectional Method

Studies individuals of varying ages at a single point in time; allows comparison of performance across different age groups in a learning task.

Longitudinal Method

Observes the same group of individuals at multiple time points as they age, allowing for analysis of changes over time.

Cohort

Refers to a group of individuals born around the same time, sharing societal events and demographic trends, influencing their behaviors and norms.

Sequential Method

A hybrid of longitudinal and cross-sectional methods where initial cross-sectional data is followed by longitudinal observations; allows for quicker data collection.

Replication

Critical for confirming findings; includes both exact and conceptual replications.

Exact Replication

Involves precise replication of study procedures to verify results, commonly used in response to unexpected findings.

Conceptual Replication

Employs different methods or measures to replicate findings, contributing significantly to behavioral understanding; emphasizes the complexity of social science variables.

Meta-Analysis

Combines results of multiple studies via statistical methods, focusing on effect sizes to provide a more objective comparison of findings across research.

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Explore the intricacies of quasi-experimental designs, particularly focusing on the one-group posttest-only design. This quiz delves into the implications of missing comparison groups and their impact on causal inferences. Test your understanding of independent and dependent variables through targeted questions.