BIOL 3327 Experimental Methods Review

These flashcards cover essential concepts and definitions related to t-tests and ANOVA from the BIOL 3327 Experimental Methods course.

What is the main function of a t-test in comparing populations?

To determine if the difference between two means is large enough, considering the variation in the biological material.

What complication arises when calculating degrees of freedom in a t-test?

The population with the largest variance will dominate the degrees of freedom.

In a paired t-test, what do we compare?

We compare the differences between paired data points from members of the same species.

What is the key difference between paired and unpaired t-tests?

Paired t-tests compare differences within matched pairs, while unpaired t-tests compare means between independent groups.

How is pooled variance calculated in a paired t-test?

Pooled variance is calculated from the differences between pairs, not individual observations.

What does the ANOVA test assess regarding treatment and background variance?

ANOVA determines if treatment variance is significantly larger than background variance.

What is the formula for calculating the ANOVA F statistic?

F = MST/MSE where MST is the mean sum of squares due to treatment and MSE is the mean sum of squares due to error.

If no real difference exists between groups, what should the ANOVA's F-ratio be close to?

Approximately 1.

What does a significant F-ratio indicate in the context of ANOVA?

It suggests that there are systematic factors influencing the variability in the data.

What is the impact of sample size on the t-distribution?

As sample size decreases, the t-distribution becomes broader and flatter, leading to wider confidence limits.