Research Methods Exam 3: Reliability, Sampling & Correlations

What are the four validities for each research claim?

Construct validity, internal validity, external validity, and statistical validity.

What is the best method for matching research claims?

The best method matches the research question to the appropriate research design.

What is test-retest reliability?

A method for calculating reliability by comparing scores from the same test taken at two different times.

What is parallel forms reliability?

A method for calculating reliability by comparing scores from two different forms of the same test.

What is split-half reliability?

A method for calculating reliability by dividing a test into two halves and comparing the scores.

What is interrater reliability?

A method for calculating reliability that assesses the agreement between different raters or observers.

What is external validity?

The extent to which research findings can be generalized to other settings, people, or times.

What is authenticity in research?

The degree to which research findings reflect real-world situations.

What is generalizability in research?

The ability to apply findings from a sample to a larger population.

What is the relationship between a population and a sample?

A population is the entire group being studied, while a sample is a subset of that population.

What are the two types of samples?

Probability (representative) and nonprobability (nonrepresentative) samples.

What are the eight specific sampling methods?

Simple random sampling, stratified sampling, cluster sampling, systematic sampling, convenience sampling, quota sampling, purposive sampling, and snowball sampling.

What is the difference between random assignment and random sampling?

Random assignment refers to assigning participants to different groups in an experiment, while random sampling refers to selecting participants from a population.

When is external validity a priority?

When the goal is to generalize findings to a broader population or different contexts.

What is sacrificed when external validity is prioritized?

Internal validity may be sacrificed, as controlling for extraneous variables can be more challenging.

What is a research hypothesis?

A specific, testable prediction about the expected outcome of a study.

What is a null hypothesis?

A statement that there is no effect or no difference, serving as a default position in hypothesis testing.

What is a scatterplot?

A graphical representation of the relationship between two quantitative variables.

What information do we get from a correlation coefficient?

The strength and direction of the relationship between two variables.

What are the types of correlational research?

Positive correlation, negative correlation, and no correlation.

How do you interpret correlational data?

By assessing the correlation coefficient value, where values closer to +1 or -1 indicate stronger relationships.

What is a hypothesis?

A testable idea or prediction about the relationship between variables.

How should hypotheses be framed?

As testable statements, not questions.

What is the difference between correlational and experimental hypotheses?

Correlational hypotheses describe associations without control over variables, while experimental hypotheses define causal relationships with control over the independent variable.

What does H₀ represent in hypothesis testing?

The null hypothesis, indicating no relationship or difference between groups.

What is a non-directional hypothesis?

A hypothesis stating that there is a relationship between variables without specifying the direction.

What is a directional hypothesis?

A hypothesis predicting the specific direction of the relationship between variables.

What is the purpose of a scatterplot?

To display the relationship between two continuous variables.

What does a positive linear relationship in a scatterplot indicate?

As one variable increases, the other variable also increases.

What does a negative linear relationship in a scatterplot indicate?

As one variable increases, the other variable decreases.

What is a curvilinear relationship?

A relationship where increases in one variable relate to both increases and decreases in another variable.

What does a correlation coefficient (r) quantify?

The strength and direction of the relationship between two continuous variables.

What range of values can a correlation coefficient (r) take?

From -1 to +1.

What does a positive correlation coefficient indicate?

Larger values of one variable predict larger values of the other variable.

What does a negative correlation coefficient indicate?

Larger values of one variable predict smaller values of the other variable.

What does an absolute value of the correlation coefficient indicate?

The strength of the linear relationship between the two variables.

What is the significance of the sign of the correlation coefficient?

It indicates the direction of the relationship (positive or negative).

What is the role of the predictor variable in correlational research?

It is the variable that is presumed to influence or predict the outcome variable.

What is the role of the outcome variable in correlational research?

It is the variable that is measured to see if it is affected by the predictor variable.

What is an example of a non-directional hypothesis?

H₁: There will be some relationship between the variables.

What is an example of a directional hypothesis?

H₁: Group 1 will perform better than Group 2.

What is the purpose of isolating the effect of one variable in experimental research?

To conclude causation between the independent and dependent variables.

What is the first step in establishing a causal relationship in experimental research?

Start with two groups that are the same.

What is the importance of manipulating the predictor variable in experimental research?

To observe the effect on the outcome variable.

What does a scatterplot with no relationship indicate?

The variables are not related to each other (H₀).

What is the relationship between covariance and correlation?

Covariance measures how two variables change together, while correlation standardizes this measure to indicate strength and direction.

What is the significance of the line of best fit in a scatterplot?

It summarizes the trend of the data points and helps predict values.

What does a positive correlation indicate?

Points have x values greater than mean(x) and y values greater than mean(y), resulting in a positive product.

What does a negative correlation indicate?

Points have x values greater than mean(x) but y values less than mean(y), resulting in a negative product.

What is the relationship between covariance and standard deviation in determining correlation strength?

The ratio between covariance and standard deviations determines strength; larger standard deviations result in a smaller r value.

What does the correlation coefficient (r) measure?

It describes the relationship between two variables and indicates the direction and strength of that relationship.

What are the ranges for interpreting the correlation coefficient (r)?

Strong: ±.50 to 1.00; Moderate: ±.30 to .50; Weak: ±.10 to .30; None: 0.

What does a larger correlation coefficient indicate?

A bigger number indicates a higher confidence in prediction.

What is the main purpose of correlational research?

To describe the relationship between measured variables without manipulating either variable.

What does correlation not imply?

Causation; correlational findings do not imply that one variable causes changes in another.

What are the potential reasons for a correlation between two variables?

Causal, direct, spurious, or coincidence.

What is a spurious relationship?

A relationship where both variables are related to some other variable and are only correlated due to that third variable.

What is an example of a correlation that does not imply causation?

Ice cream sales and sunglass sales; both increase with temperature but one does not cause the other.

What is the importance of the context in correlational studies?

The context helps to understand the meaning of the relationship and the variables being measured.

What is the null hypothesis in correlation studies?

It posits that there is no relationship between the predictor and outcome variables.

What is the predictor variable in a study?

The variable that is believed to influence or predict changes in another variable.

What is the outcome variable in a study?

The variable that is measured to assess the effect of the predictor variable.

What method was used in the study by Sun and Vazier (2018)?

Both observational and survey methods.

What does the experience sampling method measure?

Participants report their state of various personality traits multiple times a day.

What is the role of the electronic activated recorder in the study?

It provides outside ratings of participants' behaviors during the same times as their self-reports.

What is the relationship between extraversion and self-reported behavior in the study?

Stronger correlation for extraversion compared to other traits like neuroticism and agreeableness.

What should researchers consider when interpreting correlation data?

The extent to which the outcome is explained by the predictor, the definitions of the variables, and the context of measurement.

What is a direct relationship in correlation?

A relationship where changes in one variable directly correspond to changes in another variable.

What is the significance of understanding alternative hypotheses in correlation studies?

It helps to evaluate the validity of the observed relationship and consider other explanations.

What is the effect of culture on the relationship between video games and aggression?

Culture may influence the impact of video games on aggressive behaviors, suggesting a more complex relationship.

What is the importance of defining outcome variables in correlation studies?

Clear definitions help in understanding what exactly is being measured and the implications of the findings.

What does it mean if a correlation is coincidental?

The correlation exists purely by chance without any causal relationship.