Term

Definition
the variation of factors we are not controlling, or possibly even considering 


Term
What are blocking factors? 

Definition
Controllable inputs that are not of primary interest 


Term

Definition
inputs that are controllable during experimentation, but not during normal system operations 


Term
If one fails to find significance in hypothesis testing, it might still be possible to find significance if? (2 answers) 

Definition
1) Additional test runs performed 2) Different levels analyzed 3) Different factors held constant 


Term
Given 1 factor with 2 levels, what type of test would you perform to determine if there is significance? What is the basic procedure of this type of test? 

Definition
Ttest. 1) Find avg. of y1 and y2 2) Find s1 and s2 w/ formula 3) Find s(p) given s1 and s2 4) Find t(o) from formula and look up t(crit) in a table 5) if t(o)>t(crit), there is significance at given alpha level 


Term
How, in general, do you perform a double blind experiment and account for blocking factors? 

Definition
There is a master experimenter who knows which levels are receiving "placebo" vs. the real thing. The thing being tested is coded in a way that only the master experimenter knows, and gives the people running the exp. numbers only so they do not know who is getting what. Blocking factors are accounted for by having the experimenter not know the gender or the nationality of the test subject. 


Term
Where do critical values come from and how can they be derived? 

Definition
Crit. values derive from the assumption that all responses come from same distribution, and no effects assoc. w/ level changes being studied. By repeating approx. 10,000 simulated experiments, we can find a typical large value that might happen by chance near the value we look up in a table. 


Term
Can we perform randomized experiments on a planetary scale? Why or why not? 

Definition
No, the scale is simply too large, therefore we would have to rely on planetary models and simulations. 


Term
Is randomization necessary to conclude direct empirical proof? 

Definition
Yes, without randomization, no direct empirical proof is possible evidence is possible however 


Term
What does Tukey's Method do? 

Definition
Tukey's Method is a multiple comparison procedure similar to ANOVA + LSD combo. Based on a single step and designed to limit type 1 error. 


Term
Given 1 factor and more than 2 levels, what test is appropriate and what is basic procedure? 

Definition
Ftest. 1) Organize data into matrix each column = a level 2) set data matrix = grand mean matrix + estimated effects matrix + residuals matrix 3) Calc. SS, df's, and MS for factors and residuals 4) Calculate F(o) and look up F(crit) 5) If F(o) > F(crit), we can conclude significance between the levels, but don't know which ones. 


Term
When ANOVA finds significance, how do we determine which levels are significantly better than other levels? Briefly describe the procedure. 

Definition
LSD Test. 1) Calculate the absolute value of all ybar difference combos. 2) Calculate LSD using formula. 3) Compare each absolute value calculated previously to this LSD value. 4) If a difference is greater than the LSD, than we can conclude significance between those two ybar levels. 


Term
Why do ttests sometimes show significance between 2 level comparisons, when an ANOVA does not? 

Definition
A type 1 error is highly likely when using ttests on multiple level comparisons. ANOVA should be used in this case to avoid these falsified significance declarations. 


Term
Why is run order important? 

Definition
If the run order is not randomized, then we cannot generate empirical proof. The chance of systematic bias or error is likely without randomization. 


Term

Definition
An average of measured values. 


Term
How do you calculate the "estimated effect" in an ANOVA test? 

Definition
The column average minus the grand mean (for balanced orthogonal designs). Difference between the model prediction conditioned on a level and the grand mean. 


Term

Definition
The allocation of blocking factor levels including run order in an unpatterned way 


Term
What is a residual/ how is it calculated? 

Definition
The difference between the model prediction (column avg.) and the actual values. Aka "estimated error." 


Term
What is a fractional factorial experiment? 

Definition
A subset of a full factorial experiment. A randomized plan involving fewer than all combinations of relevant factor levels. 


Term

Definition
A setting that a factor can assume. 


Term

Definition
the difference in the avg. response when a factor is at the high level minus the avg. at the low level. 


Term

Definition
not associated with any specific distributional assumption 


Term
What is a random variable? 

Definition
a number with an unknown value at the time of planning by the planner. 


Term
What is the purpose of a master guide sheet? 

Definition
To aid in experimental planning. 


Term
What is an empirical model? 

Definition
A quantitative inputoutput relationship derived from experimental data 


Term

Definition
A value of alpha that makes the test statistic equal to the critical value 


Term
Why would Tukey's method be preferred over other approaches? 

Definition
Has a lower chance of making at least 1 type 1 error. (but higher type 2 rate) 

