Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Biostatistics Final
Analysis of Variance
| Question | Answer |
|---|---|
| Inflation of Type I Error | Each t-test has a type I error of alpha, however over a series of multiple t-tests the overall type I error does not stay at alpha but grows w/ each new comparison. |
| Analysis of Variance (ANOVA) | Compares multiple pop. means that avoids the inflation of type I error rates. Test one null hypothesis to determine if any of the pop. mean differ from the rest. Type I error remains at alpha. Use w/ interval/ratio data. |
| One-Factor ANOVA | "One factor" mean that b/w all groups, there is only one source of variation investigated. |
| Independent Sample ANOVA Assumptions | Population: all pops. are normally dist., all pops. have same variance. Sampling: samples are independent of one another, each sample obtained by SRS from pop. |
| Mean Square Within/Error | Pool all the sample variances. When the sample sizes are the same the pooled variance is the average of the individual sample variances. DF=N-k N:total # of obs. k:# diff. pop. Good estimate of pop. variance when null is correct & incorrect. |
| Mean Square Among/Treatment | Based on the sample means. DF=k-1. Good estimate of pop. variance only when null is correct. |
| Two Main Points | MSW is based on variability w/n each sample. MSA only good when all sample means can be considered from same pop. If null is true, MSA & MSW should be similar & ratio should be close to 1. |
| Partitioning the Sum of Squares | SSA:among groups sum of squares df=k-1. SSW:w/n groups sum of squares df=N-k. SST:total sum of squares SSW+SSA df=N-1. |
| One-Factor ANOVA for Dependent Samples | Goal is to decide if there is a difference among the dependent pop. means. Randomized complete block (two-way) & repeated measures. MST has k-1 df & MSE has N-k-b+1 df. SSB has b-1 df. SST has N-1 df. |
| Dependent Samples Assumptions | Population: normally dist. pops., variances are same, scores in all pairs of pops. should have same degree of relationship. Sample: samples are dependent, observations come from SRS from pop. |
Created by:
horsenerd09
Popular Math sets