Graduate Research Methods (Pt 1) Test 1

What are the three components of behavioral science?

Research that generates knowledge, theory that organizes knowledge, and application that puts knowledge to use.

Define science in the context of behavioral science.

A systematic process for generating knowledge about the world.

What are the three aspects of science?

Goals, key values and perspectives.

List key values in behavioral science.

Empiricism, skepticism, tentativeness, publicness, and epistemology.

What are the two types of data analysis in behavioral science?

Quantitative (using numbers) and qualitative (using language).

What is the first step in the research process?

Develop ideas for research.

What is a hypothesis?

A prediction formed from a theory.

What is the difference between an independent variable and a dependent variable?

The independent variable is manipulated by the researcher, while the dependent variable is measured and not manipulated.

What are the levels of measurement in behavioral science?

Categorical, ordinal, interval, and ratio variables.

What is measurement error?

The discrepancy between the actual value we are trying to measure and the number we use to represent that value.

What is validity in research?

Evidence that a test measures what it is supposed to measure.

What is reliability in the context of measurement?

The ability of the measure to produce the same results under the same conditions.

What distinguishes basic research from applied research?

Basic research is conducted to generate knowledge for the sake of knowledge, while applied research seeks to find solutions to problems.

What is correlational research?

Observing what naturally occurs in the world without directly interfering.

What is experimental research?

Systematically manipulating variables to see their effects.

Define confounding variables.

A variable other than the independent variable that potentially affects the dependent variable.

What is the purpose of randomization in research?

To minimize systematic variation.

What are descriptive statistics used for?

To describe data and summarize characteristics of a dataset.

What is inferential statistics?

Using sample data to generalize findings to a larger population.

What is a frequency distribution?

A graph plotting values of observations on the horizontal axis, showing how many times each value occurred in the dataset.

What does skew refer to in frequency distributions?

The symmetry of the distribution, indicating how scores are bunched.

What does kurtosis measure in a data distribution?

The 'heaviness' of the tails of the distribution.

What is the difference between leptokurtic and platykurtic distributions?

Leptokurtic distributions have heavy tails, while platykurtic distributions have light tails.

What are the three measures of central tendency?

Mean, median, and mode.

How does changing a score affect the mean?

Changing a score will change the mean; introducing or removing a score also affects it.

What is the median in a set of scores?

The midpoint in a set of scores.

What is the mode?

The most frequently occurring score in a data set.

What does the range measure in statistics?

The difference between the largest and smallest score.

What is the interquartile range?

The range between the lower and upper quartiles, which splits data into equal parts.

What does standard deviation indicate?

The average distance of scores from the mean, reflecting how spread out the scores are.

What is variance?

A measure of how much scores differ from the mean, calculated as the average of squared deviations.

What is the relationship between standard deviation and outliers?

Standard deviation is sensitive to outliers; extreme scores can significantly affect it.

What is the formula for calculating the probability of an event?

If an event can occur in A ways and fail in B ways, the probability of occurrence is A/(A + B).

What is the difference between independent and dependent events?

Independent events do not affect each other's outcomes, while dependent events do.

What does mutually exclusive mean in probability?

If one event occurs, it excludes the possibility of another event occurring.

What is the normal curve?

A visual representation of score distribution where mean, median, and mode are equal and symmetrical.

What do Z-scores represent?

The number of standard deviations a score is from the mean, allowing for standardization across distributions.

What is the significance of a Z-score of ±1.96?

It cuts off the top and bottom 2.5% of the distribution, indicating that 95% of Z-scores lie between these values.

What is hypothesis testing in relation to Z-scores?

Z-scores help determine the probability of an event, indicating if a result is statistically significant.

What is the purpose of reporting confidence intervals?

To provide a range of values that likely contains the true population parameter.

What is a population in statistical terms?

The complete set of units to which findings or models are generalized.

What is a sample?

A smaller collection of units from a population used to infer truths about that population.

What does the term 'fit' refer to in statistical models?

The degree to which a statistical model represents the data collected.

What is the method of least squares?

A statistical method used to estimate parameters by minimizing the sum of squared errors.

Determines the line of best fit.

What is sampling variation?

The differences in sample statistics that arise from using different members of a population.

What is the sum of squared errors?

The total of the squared deviations from the mean, used to measure total dispersion.

What is a sampling distribution?

The frequency distribution of sample means (or any other parameter) from the same population.

What does the standard error represent?

The standard deviation of sample means, used to estimate the mean and standard deviation of a population.

What is a confidence interval (CI)?

A range of values constructed so that a certain percentage of samples will contain the true population parameter.

What is the significance of a 95% confidence interval?

It indicates that 95 out of 100 confidence intervals will contain the true population mean.

What is a scientific hypothesis?

A testable supposition that accounts for certain facts and guides further investigation.

What is statistical inference?

The process of observing a sample from a population to make decisions about the truth of a scientific hypothesis.

What is the null hypothesis?

A statement asserting no effect or no difference, serving as a benchmark for comparison.

What is the alternative hypothesis?

The hypothesis that proposes a potential effect or difference, corresponding to the researcher's scientific hypothesis.

What are Type I and Type II errors?

Type I error is rejecting a true null hypothesis; Type II error is failing to reject a false null hypothesis.

What does it mean if the null hypothesis is not rejected?

It may indicate that the null hypothesis is true, or that the sample is not representative, or the methodology is not sensitive enough.

What is hypothesis testing?

The process of determining whether to reject the null hypothesis based on sample data.

What is p-hacking?

The practice of manipulating data or analysis to achieve significant p-values, often leading to selective reporting.

What is HARKing?

Hypothesizing After Results are Known; presenting hypotheses made after data collection as if they were made beforehand.

What is the purpose of preregistration in research?

To make all aspects of the research process publicly available before data collection begins, enhancing transparency.

What is an effect size?

A quantitative measure of the magnitude of a phenomenon, indicating the strength of a relationship or effect.

What is the alpha level in hypothesis testing?

The threshold for determining statistical significance, commonly set at 0.05.

What does a significant p-value indicate?

It suggests that the observed effect is unlikely to have occurred by chance, but does not imply practical importance.

What is the difference between one-tailed and two-tailed tests?

One-tailed tests predict a direction of the effect, while two-tailed tests do not specify a direction.

What is the beta level in hypothesis testing?

The probability of making a Type II error, often set at 0.2.

What is the role of test statistics in hypothesis testing?

To calculate the probability of obtaining observed values under the null hypothesis.

What does it mean if a result is statistically significant?

It indicates that the result is unlikely to occur under the null hypothesis, but does not confirm the null hypothesis is false.

What is the misconception about non-significant results?

A non-significant result does not confirm that the null hypothesis is true; it only suggests that the effect is not large enough to detect.

What are the implications of researcher degrees of freedom?

Researchers may manipulate study design or analysis to achieve favorable results, potentially leading to questionable practices.

What does 'all-or-nothing thinking' refer to in statistical analysis?

The tendency to view p-values as definitive indicators of truth, neglecting the importance of effect size and consistency.

What is the significance of the 99% confidence interval?

It indicates that 99 out of 100 confidence intervals will contain the true population mean, requiring a larger margin of error than 95%.

What is effect size?

A standardized measure of the size of an effect, allowing for comparison across studies.

What are the advantages of using effect sizes?

They encourage interpreting effects on a continuum, are less reliant on sample size, and reduce p-hacking.

What is Cohen's d?

A measure of effect size calculated as the difference between two group means divided by the pooled standard deviation.

What does a Cohen's d of 0.2 indicate?

A small effect size that accounts for 1% of the total variance.

What does a Cohen's d of 0.5 indicate?

A medium effect size that accounts for 9% of the total variance.

What does a Cohen's d of 0.8 indicate?

A large effect size that accounts for 25% of the total variance.

What is an odds ratio?

The ratio of the odds of an event occurring in one category compared to another.

What does an odds ratio of 1 indicate?

The odds of an outcome are equal in both categories.

What is meta-analysis?

A method that computes effect sizes from multiple studies and takes a weighted average of those effect sizes.

What is Bayesian statistics?

An approach that uses data to update beliefs about a model parameter or hypothesis.

What is Bayes' theorem?

A formula that relates the conditional and marginal probabilities of random events.

What is posterior probability?

Our belief in a hypothesis after considering the data.

What is prior probability?

Our belief in a hypothesis before considering the data.

What is the likelihood in Bayesian statistics?

The probability that the observed data could be produced given the hypothesis or model being considered.

What does a Bayes factor greater than 1 suggest?

The observed data are more likely given the alternative hypothesis than the null hypothesis.

What is an unbiased estimator?

An estimator that yields an expected value equal to the true value it aims to estimate.

What is statistical bias?

The error between individual observations and a statistical model that can distort parameter estimates.

What is homogeneity of variance?

The assumption that the variance of errors is the same across all values of the predictor.

What is the Central Limit Theorem?

The principle that states the sampling distribution will be normal if the sample size is greater than 30.

What is the purpose of robust tests?

To provide accurate results even when assumptions of normality and homogeneity of variance are violated.

What is Levene's test used for?

To assess whether the variances in different groups are equal.

What is the effect of outliers on statistical analysis?

Outliers can bias parameter estimates and the associated standard errors, confidence intervals, and test statistics.

What is the purpose of transforming data?

To stabilize variance and reduce skewness in the data.

What is a log transformation used for?

To reduce positive skew in the data.

What is a square root transformation used for?

To reduce positive skew and stabilize variance.

What is the difference between arithmetic means and geometric means?

Arithmetic means are used for normally distributed data, while geometric means are used after log transformation.

What does a Bayes factor less than 1 indicate?

It supports the null hypothesis, suggesting weakened belief in the alternative hypothesis.

What is the significance of a Bayes factor between 3 and 10?

It is considered evidence that has substance for the alternative hypothesis.

What is the role of bootstrapping techniques?

To provide robust estimates by resampling the data.