Inferential Statistics Flashcards
“How can you tell whether your sample mean is a good estimate of the population mean?”
You can calculate the standard error of the mean (SE; sometimes also referred to as SEM)
What is standard error
considers the variability in the sample of means drawn from the population
what do smaller SEs suggest and what to larger SEs suggest
Smaller SEs suggest you have a relatively accurate estimate of the population mean.
Larger SEs suggest you have a less accurate estimate of the population mean.
what is the equation for standard error
SE= SD divided by square root of number of scores
what is a one tailed hypothesis
A statement in which the direction of the difference/association is specified
what is a 2 tailed hypothesis
A statement in which the direction of the difference/association is not specified
what significance is there if P value is >0.5
none
- If p value is below .05 there is significance
what influences power
Alpha level (threshold for statistical significance)
Effect Size
Sample size
what is a type 1 error
Determined by our alpha-value (a). Typically set at a rate of 0.05 (our significance level)
i.e., we will incorrectly reject the null hypothesis less than 5% of the time
what is a type 2 error
Type II Error = False-negative
Relevant when there IS an effect in the population
Determined by our power value (β). Typically set at a rate of 0.80
i.e., we will incorrectly accept the null hypothesis less than 20% of the time
