Inferential Statistics Review

A comprehensive set of flashcards designed to reinforce key concepts in inferential statistics and statistical significance relevant for chiropractic research.

What is the main purpose of inferential statistics?

To test a hypothesis and determine the generalizability of findings from a sample to a population.

What is a population in statistical terms?

All individuals or items of interest in a particular study.

What does the term 'parameter' refer to?

A fixed number measurement that describes a characteristic of the whole population.

What is a sample in statistics?

A subset of the population used to obtain information, ideally chosen randomly and without bias.

Define 'statistic' in terms of data analysis.

A measurement that describes characteristics of a sample.

What is a point estimate?

A single value estimate of a population parameter.

What is an interval estimate?

A range of values where a population parameter is expected to lie.

What does a confidence interval account for?

Sampling errors and uncertainty.

What is the interpretation of a confidence interval of (16-22) at 95%?

With 95% confidence, we expect the true population parameter to lie between 16 and 22.

What statistical test compares differences between two unrelated groups?

Independent t-test or '2-sample' t-test.

What is a dependent t-test?

A statistical test used for one group measured twice, e.g., pre-care and post-care.

What type of statistical test is used for three or more unrelated groups?

One-way ANOVA.

What type of ANOVA is used for repeated measures?

Repeated Measures ANOVA.

What does 'Chi-square (χ2)' test assume about the data?

That all numbers in the cells are larger than 5.

What is the function of Kappa (κ) statistic?

To measure inter-rater reliability for categorical data.

What does ICC stand for in statistical analysis?

Intraclass Correlation Coefficient, used for continuous data.

What does a p-value indicate?

The probability that the results observed in a sample are due to chance.

A p-value less than what level is generally considered statistically significant?

p ≤ .05.

What does a significant correlation of 0.62 imply about two variables?

There is a strong association, though correlation does not imply causation.

What is the role of linear regression analysis?

To predict a dependent variable based on one or more predictor variables.

What type of data does Pearson r correlate?

Continuous data.

What type of correlation coefficient is Spearman rho typically used for?

Ordinal data.

What does a correlation near -1 indicate?

A strong negative correlation.

What does a correlation near 1 indicate?

A strong positive correlation.

Define statistical significance in the context of hypothesis testing.

The likelihood that a relationship or effect observed in a study is not due to sampling error.

What is the purpose of using confidence intervals in research?

To provide a range of plausible values for the population parameter based on sample data.

What is an example of a confounding variable?

A variable that influences both the dependent and independent variable causing a spurious association.

Describe 'inter-rater reliability.'

The degree of agreement among independent observers measuring the same phenomenon.

How is intra-examiner reliability assessed?

By having the same examiner measure the same subjects on multiple occasions.

What is 'examiner agreement'?

Comparison of findings from inter-examiner or intra-examiner measurements.

What constitutes a significant correlation for PROMIS CAT instruments and ODI in chiropractic patients?

A Pearson correlation value greater than or equal to 0.7224.

What does it mean when the confidence interval crosses 0?

It indicates the possibility that there is no effect or difference between groups.

What is the margin of error in a confidence interval?

The range between the point estimate and the bounds of the confidence interval.

What type of variables are suitable for logistic regression?

Categorical dependent variables.

What is a potential flaw in interpreting statistical correlations?

Assuming that correlation implies causation.

In the context of the Affordable Care Act, what type of analysis was likely performed?

Public opinion polling or inferential statistics based on sample data.

How do you determine the predictive value of a variable?

By assessing how well a predictor variable explains or predicts changes in a dependent variable.

What is meant by 'common cause' in statistical analysis?

A variable that influences multiple dependent variables creating a false impression of association.

What characterizes the findings of the 'Storks Deliver Babies!' phenomenon?

A misleading correlation that does not imply a causal relationship.

What is the primary takeaway regarding p-value interpretation?

High statistical significance does not always equate to high practical significance.

What measurement indicates a low p-value?

A p-value of less than 0.05, indicating strong evidence against the null hypothesis.

What is the primary goal of regression analysis?

To predict the outcome of a dependent variable based on one or more independent variables.

What type of data does the independent t-test compare?

Continuous data from two unrelated groups.

Define the term 'statistical power.'

The probability of correctly rejecting the null hypothesis when it is false.

What is a Type I error in hypothesis testing?

Rejecting the null hypothesis when it is true.

What role do samples play in inferential statistics?

Samples provide insights into population parameters without examining the entire population.

Why is random sampling important?

It minimizes bias and allows for generalizability of the findings to a larger population.

What is the significance of having an adequate sample size?

It increases the validity and reliability of the study's results.