Exam 3

what is correlational research?

what is correlational research?

A type of research often used in surgery's to assess relationships between variables without implying causation

what is internal consistency reliability

the degree to which individual item in a scale are interrelated, often assessed with cronbach's alpha.

Define Cronbach's alpha

a statistic ranging from 0.0 to +!.0 used to evaluate the internal consistency reliability of a scale.

What is test-retest reliability?

The temporal stability of a measure, assessed by correlating scores from two testing sessions.

Explain alternative-form reliability

Reliability assessed by correlating two versions of a scale that measure the same variable in different forms.

What is inter-rater reliability?

The degree of agreement between two raters observing the same behavior, often measured by percent agreement or kappa coefficient.

Define face validity

The extent to which a scale appears to measure the intended variable on the surface.

What is content validity?

The extent to which a scale includes items that cover the full range of the concept being measured.

Define construct validity

The extent to which a scale actually measures the construct it intends to measure, assessed by convergent and discriminant validity.

What is convergent validity?

The degree to which scores on a measurement correspond with measures of theoretically related variables.

What does discriminant validity assess?

Whether a measurement does not correlate with variables it is not supposed to be related to.

Define criterion validity

The extent to which a measurement relates to a particular outcome or behavior, including concurrent and predictive validity.

What is the correlation coefficient?

A measure indicating the strength and direction of a linear relationship between two variables, ranging from -1.0 to +1.0.

Explain the difference between continuous and categorical variables in correlational research

Continuous variables have a range of values, while categorical (or dichotomous) variables have distinct groups or categories.

What does the statement "correlation does not imply causation" mean?

Although two variables may be correlated, it does not mean one variable causes the other.

What is a scatter plot?

A graph where each point represents the values of two variables, used to visually assess their relationship.

Define point-biserial correlation

A correlation where one variable is continuous and the other is dichotomous, often coded as 0 or 1.

What is the phi coefficient used for?

Calculating the correlation between two dichotomous variables.

Why might a researcher use alternative methods like ANOVA or multiple regression in correlational research?

These methods allow for more complex analyses beyond simple correlations, such as assessing multiple variables simultaneously.

What is covariation in experimental design?

It's the association between changes in one variable and changes in another, an essential step in determining causality.

Define temporal precedence

It's when changes in the suspected cause (independent variable) occur before changes in the effect (dependent variable), helping establish causation.

What are extraneous variables?

Factors other than the intended treatment that could affect the outcome, potentially confounding results.

Explain internal validity

It refers to the degree to which alternative explanations for an observed relationship can be ruled out.

What is external validity?

The extent to which the results of a study can be generalized to other contexts or populations.

What is ecological validity?

A type of external validity that refers to how well study findings generalize to real-world settings.

Describe the independent variable (IV) in the texting study example.

Rules about phone use, specifically whether participants are required to ignore texts or are allowed to check them.

What is the dependent variable (DV) in the texting study example?

The amount of distraction, measured by performance on a task.

What is a manipulation check?

A measure to confirm that the manipulation effectively varied the independent variable across conditions.

Define between-subjects design.

An experimental design where different participants are assigned to each group or condition.

What is an independent samples t-test?

A statistical test that compares the means of two independent groups to see if they are significantly different.

Explain the concept of statistical significance in a t-test.

It indicates the probability that the observed results are not due to chance, commonly set at a p-value of .05.

What is a p-value?

The probability that the results of a test occurred by chance, with a common threshold of 0.05 for significance.

Define statistical power in an experiment.

The likelihood of detecting an effect if there is one; it can be increased by larger sample sizes and consistent procedures.

Why are manipulation checks important?

They verify that the experimental manipulation was effective, which helps in interpreting the study's findings.

In the context of the texting study, what was found about distraction levels?

The high-restriction group reported feeling more distracted than the low-restriction group.

Why is it necessary to test for alternate explanations?

To ensure observed effects are due to the manipulation and not other variables that could confound results.

How is APA style used in reporting results?

It provides structured guidelines for presenting statistical findings, including test values, p-values, and effect sizes.

What is a multigroup design?

A research design involving three or more groups to compare different treatments or conditions.

Define placebo group

A group where participants believe they are receiving treatment but are not, used to control for the placebo effect.

What is an empty control group?

A group that receives no treatment and is only assessed on the dependent variable, serving as a baseline.

What is a waiting-list control (WLC) group?

Participants receive the intervention later, allowing researchers to compare immediate versus delayed treatment effects.

Why is including a placebo group beneficial?

It helps determine if observed effects are due to the treatment itself or participants' expectations of improvement.

What is the controversy over antidepressant medications like Prozac?

Recent studies suggest that SSRIs may not be more effective than placebos or exercise for mild depression, with higher relapse rates after discontinuation.

Why might researchers use three groups in a study?

To compare multiple treatments or conditions, understand nuances between groups, or add control/comparison groups for more accurate results.

Describe the purpose of an "attention placebo" group.

A group that receives similar attention as the treatment group but lacks the active treatment, isolating the effects of attention on outcomes.

What is the role of an omnibus F test in ANOVA?

It identifies if there is a significant difference among three or more means but doesn't specify where the difference lies.

What is a post-hoc test, and why is it used?

A test conducted after an ANOVA to determine which specific groups differ significantly from each other.

Explain the concept of nonspecific factors in psychotherapy.

Factors like empathy, attention, and support that can produce positive effects regardless of the specific treatment.

What insight did Strupp & Hadley's study provide on psychotherapy?

Both professional therapists and college professors led to improvements, highlighting the importance of nonspecific factors in therapy.

Why use three groups in the study of homelessness by Toro and colleagues?

To distinguish characteristics unique to homelessness versus poverty and to explore a possible continuum of poverty.

What was the rationale for studying homeless individuals across different age groups?

To understand age-related differences, as homeless adolescents differ significantly from adults in both quantitative and qualitative ways.

How does multigroup design enhance research efficiency?

By comparing multiple groups in a single study, researchers can gather more comprehensive data with fewer resources.

Define correlational research and explain why it cannot establish causation.

Correlational research examines the relationship between two or more variables without manipulating them. It cannot establish causation because it lacks experimental control, meaning it cannot rule out third variables or determine the direction of the relationship.

Describe Cronbach's alpha and explain its purpose in reliability testing.

Cronbach's alpha is a statistic that ranges from 0 to +1.0 and is used to assess the internal consistency reliability of a scale. A higher alpha indicates that the items are more consistent in measuring the same concept.

Differentiate between test-retest reliability and alternative-form reliability.

Test-retest reliability assesses the stability of a measure over time by testing the same individuals twice. Alternative-form reliability involves using two different versions of the same test to determine if they produce similar results.

What is the purpose of a manipulation check in research, and when would it be used?

A manipulation check is used to verify if the experimental manipulation successfully influenced the independent variable. It is used to ensure that any observed effects are due to the intended manipulation and not other factors.

What is the difference between a high-restriction group and a low-restriction group in an experimental design? Provide an example of each.

A high-restriction group has strict rules (e.g., no cell phone use), while a low-restriction group has fewer restrictions (e.g., allowed to check texts). These groups help test the effects of varying levels of restriction on behavior.

Define and explain the importance of internal validity in experimental research.

Internal validity is the extent to which a study can establish a causal relationship by controlling for extraneous variables. It ensures that observed effects are due to the independent variable and not other factors.

What is the independent samples t-test, and when would it be used?

The independent samples t-test compares the means of two independent groups to see if they are significantly different. It is used in experiments with two separate groups.

Explain what a p-value represents in statistical testing. What does a p-value of 0.05 indicate?

A p-value indicates the probability that the results occurred by chance. A p-value of 0.05 means there is a 5% probability that the observed results are due to random variation.

In a two-group experiment, why is it important to rule out alternative explanations for the results?

Ruling out alternative explanations ensures that any observed effects are due to the manipulation of the independent variable, increasing confidence in causal conclusions.

What is a multigroup design, and why might researchers choose it over a two-group design?

A multigroup design includes three or more groups, allowing researchers to compare multiple treatments or conditions and gain more comprehensive insights.

Define a placebo group and explain its role in experimental research.

A placebo group is a control group that believes they receive treatment but do not. It helps control for the placebo effect, isolating the effect of the actual treatment.

What is an empty control group, and when might it be used?

An empty control group receives no treatment and serves as a baseline to compare the effects of the intervention.

Discuss the purpose of a waiting-list control group and provide an example.

A waiting-list control group receives the intervention later, allowing comparison between immediate and delayed effects. For example, in a therapy study, one group receives therapy now, while another waits.

Explain the purpose of an “attention placebo” group in multigroup design research.

An attention placebo group receives similar attention as the treatment group without the active treatment, helping to isolate the effects of attention alone on outcomes.