stats tests Flashcards
(12 cards)
What is the pneumonic you must know for stats tests?
Carrots Should Come
Mashed With Swede
Under Roast Potatoes
What the the pneumonic stand for
Carrot: Chi Squared
Should:Sign Test
Come: Chi Squared
Mashed: Mann Whitney
With: Willcoxon
Swede: Spearman’s Rho
Under: Unrelated T test
Roast: Related T Test
Potatoes: Pearsons
When should a Chi-squared test be used?
• Used for nominal data
• Tests the relationship between two categorical variables
• Example: Does gender affect voting preference (yes/no categories)?
When is the Mann-Whitney U test used?
• Used for ordinal data or when the data doesn’t meet parametric assumptions
• Compares the differences between two independent groups
• Example: Comparing satisfaction scores between two groups
When should a Wilcoxon Signed Rank Test be used?
• Used for ordinal data or paired data
• Compares the differences between two related groups (e.g., before and after scores)
• Example: Pre- and post-test scores in the same participants
When is a Spearman’s Rho used?
• Used to measure the strength and direction of a relationship between two variables
• Ideal for ordinal data
• Example: Relationship between time spent revising and exam performance
When is a Pearson’s Correlation used?
• Used when there is a linear relationship between two variables
• Ideal for interval/ratio data
• Example: Relationship between height and weight
When is a T-test used?
• Used to compare the means of two groups
• Independent t-test: For two independent groups (e.g., control vs. experimental)
• Paired t-test: For related groups (e.g., pre/post measures in the same participants)
• Data should be interval/ratio and normally distributed
What are the steps involved in choosing a statistical test?
1) Experiment and Correlation
2) What Experimental design is it?
3)What level of measurement
What are Type I and Type II errors?
• Type I error: False positive – Rejecting a true null hypothesis (finding an effect when there is none).
• Type II error: False negative – Failing to reject a false null hypothesis (not detecting an effect that exists).
What does p-value indicate in statistical testing?
The p-value represents the probability of obtaining the observed results if the null hypothesis is true.
• A p-value < 0.05 indicates statistical significance (reject the null hypothesis).
How do you interpret a significant result in hypothesis testing?
If p < 0.05, it means that the result is statistically significant, and we can reject the null hypothesis, suggesting that the observed effect or relationship is unlikely to have occurred by chance.
