ACTUAL QUESTIONS AND CORRECT
ANSWERS
Model or theory - CORRECT ANSWER explanation of an observed pattern, usually relate a
response (DV) to one or more factors (IV)
Manipulative experiments vs natural experiments - CORRECT ANSWER manipulative:
random, representative, replicable, have potential to reveal causation
Natural: large scale, no randomization, no replication, only capable of revealing association
Traits of a good hypothesis - CORRECT ANSWER internal consistency, explanatory value,
advances knowledge, testable
Three R's of experiments - CORRECT ANSWER randomization
Representation
Replication
Can we prove that a hypothesis is true or false by a statistical test? - CORRECT ANSWER no,
we can only determine that there are reasonable grounds for rejecting or failing to reject the
hypothesis
Inductive logic rules only permit the possibility of... - CORRECT ANSWER rejecting a
hypothesis, never acceptance
There is always a possibility of error because... - CORRECT ANSWER we have not observed
the entire population
The _____ is the probability of observing the sample test statistic if H0 is true - CORRECT ANSWER
p-value
T-testing hypotheses - CORRECT ANSWER - H0 says the value is equal
,- HA says the value is greater than, less than, or unequal
- either reject H0 or fail to reject H0
Type I error - CORRECT ANSWER rejects a null hypothesis that is actually true (false
negative)
Type II error - CORRECT ANSWER fails to reject a null hypothesis that is actually false
(false positive)
One-sided v. Two-sided - CORRECT ANSWER two-sided: describes departure from H0 in two
directions (non-directional)
One-sided: described departure from H0 in a specific direction (directional)
The default is a _____ t-test - CORRECT ANSWER two-sided
If HA: u1 - u2 < 0, calculate P from the _____ tail (less than 0) only - CORRECT ANSWER
lower
If HA: u1 - u2 > 0, calculate P from the _____ tail (greater than 0) only - CORRECT ANSWER
upper
The confidence interval is based on the underlying __________ of the population from which the
sample is drawn - CORRECT ANSWER probability distribution
Standard deviation for a population - CORRECT ANSWER o = square root [(sum of values -
mean value)^2 / (n)]
Standard deviation for a sample - CORRECT ANSWER o = square root [(sum of values -
mean value)^2 / (n - 1)]
Standard error - CORRECT ANSWER SE= standard deviation / square root(n)
, The standard t-test to compare two means makes two important assumptions: - CORRECT ANSWER
1) the observations are random samples from a normal distribution
2) the variances of the two populations are equal
Multi-resource inventories provide information on... - CORRECT ANSWER structure,
variability, and processes
Surveys are best _____ for efficiency - CORRECT ANSWER stratified
Components of multi-resource inventories: - CORRECT ANSWER - coarse woody litter
(LOD)
- groundstory component
- understory component
- overstory component
Name three types of information collected for forest inventory and analysis (FIA) - CORRECT
ANSWER - soil quality
- LOD
- vegetation structure and diversity
- crown condition and canopy characteristics
- tree mortality
- tree growth
- lichen communities
- vegetation health
Sample survey design steps - CORRECT ANSWER 1) define target population
2) define sample unit
3) define required accuracy and precision (confidence interval)
4) decide how sample will be collected
5) decide how many sample units will be measured (n)
6) know budgeting limitations