Comparing Two Means

Question 1

Parametric Statistics

Answer 1

Branch of statistics which assumes that sample data comes from a population that follows a probability distribution based on a fixed set of parameters

Question 2

Scale Data (Ratio or Interval)

Answer 2

Calculate means and variance, so data should be continuous

Question 3

Equal Variance

Answer 3

Used when there is more than one group (t-test, ANOVA)
Groups were “roughly equivalent” before starting (can be tested statistically)

Question 4

Normality

Answer 4

Data are sampled from a population with a normal distribution
Can be tested statistically

Question 5

T-Test

Answer 5

Comparing two means
Does the observed difference in sample scores represents a “real” difference in the population… vs. just sampling error?
Two levels of one independent variable (two different groups, one single group with two interventions, one single group with pretest and posttest measurements (time))

Question 6

Degrees of Freedom

Answer 6

The number of independent pieces of information that went into calculating the estimate
We are calculating the number of values that are free to vary

Question 7

Unequal Variances

Answer 7

Not a major issue when the sample sizes are equal. When the variances are significantly different, the t-ratio must be adjusted

Question 8

Effect Size

Answer 8

The measure of effect the independent variable has on the dependent variable