The General Linear Model Flashcards
(42 cards)
What is the General Linear Model?
A statistical model used to explain the relationship between dependent and independent variables
It encompasses various techniques including regression analysis.
What is the purpose of descriptive statistics?
Useful for summarizing and describing the characteristics of a dataset
It is primarily focused on single variables.
What is a dependent variable?
The variable that is being measured or tested in an experiment
Also known as the response variable.
What is an independent variable?
The variable that is manipulated or controlled in an experiment
Also known as the predictor variable.
What does a null hypothesis represent?
A statement that there is no effect or no difference
It is the hypothesis that the study seeks to test against.
What does an alternative hypothesis represent?
A statement that there is an effect or a difference
It is what researchers aim to support through their data.
What does a p-value indicate?
The probability of observing the results, or more extreme results, if the null hypothesis is true
A low p-value suggests that the null hypothesis may be rejected.
What does p < 0.05 indicate?
Statistically significant result, suggesting the null hypothesis can be rejected
It implies a low probability of the result occurring by chance.
What is a Type 1 error?
Incorrectly rejecting the null hypothesis when it is actually true
Also known as a false positive.
What does ‘statistically significant’ mean?
Indicates that the results are unlikely to have occurred by chance
It does not imply that the result is medically significant.
What is effect size?
A quantitative measure of the magnitude of the experimental effect
It helps in understanding the practical significance of the findings.
What is an independent samples t-test used for?
Comparing the means of two independent groups
It tests whether there is a significant difference between the two groups.
What does ANOVA stand for?
Analysis of Variance
It is used to compare means across three or more groups.
What is a post hoc test?
A follow-up test conducted after ANOVA to determine which specific groups differ
It usually involves modified t-tests.
What is the purpose of linear regression?
To test the relationship between two numeric variables
It assesses whether the slope of the fitted line is significantly different from zero.
What does the correlation coefficient (r) measure?
The strength and direction of a linear relationship between two variables
It ranges from -1 (perfect negative correlation) to 1 (perfect positive correlation).
What are the assumptions for valid statistical tests?
Observations must be random and independent, equal variance, and normal distribution around the fitted model
These assumptions ensure the reliability of the statistical results.
What is a causal relationship?
A relationship where one variable directly affects another
It implies that changes in one variable will produce changes in another.
What is the significance of a small p-value?
Indicates a low probability that the observed results are due to chance, suggesting a real effect exists
Typically, p < 0.05 is considered statistically significant.
What does p >= 0.05 indicate?
Insufficient evidence to reject the null hypothesis
It suggests that any observed difference may be due to sampling variation.
What is the role of sample size in statistical testing?
Larger sample sizes generally provide more reliable estimates and reduce the chance of Type 1 errors
They help in detecting true effects if they exist.
What is the relationship between sample mean and population mean?
The sample mean is an estimate of the population mean
It may vary due to sampling error.
Do two newly-developed drugs work better than a placebo?
Yes, one may be better than the other
Is the survival time after surgery better for a new technique?
It may be improved or not
