CSU FW 370 Exam Study Guide – Practice Questions, Flashcards &
Exam Review
Deduction or Induction?
1. All of the ants in the Harvard forest belong to the genus Myrmica
2. I sampled this particular ant in the harvest forest
3. This ant is in the genus Myrmica - ANS ✔✔Deduction
Deduction or Induction?
1. All 25 of these ants are in the genus myrmica
2. All 25 of these ants were collected in the Harvard forest
3. All of the ants in the Harvard forest are in the genus myrmica - ANS ✔✔Induction
The scientific method is:
a) a technique used to decide among hypotheses on the basis of observations and predictions
b) a technique that involves both deduction and induction
c) all of the above
d) none of the above - ANS ✔✔c) all of the above
Creet et al. (2002) found that wolves in Yellowstone that are exposed to snowmobiles have 872
ng GC/g in their blood, whereas wolves that are not exposed to snowmobiles have 1468 ng
GC/g (GC stands for Glucocorticoid hormones). They propose to conduct a two-tailed t-test to
address the scientific hypothesis that snowmobiles may be responsible for the observed
increase stress levels in the group of wolves that is exposed to that disturbance.
,Accordingly, they formulate their null and alternative hypothesis:
(H0): The difference in mean GC between groups is no greater than what we would expect to
find by chance alone.
What would be an appropriate alternative hypothesis (HA)?
a) the presence of snowmobiles does not explain the difference between GC levels across the
two groups
b) the difference in GC levels between the 2 groups is too large to be accounted for by chance
alone and could be due to the presence of snow - ANS ✔✔b) the difference in GC levels
between the 2 groups is too large to be accounted for by chance alone and could be due to the
presence of snowmobiles
According to Gotelli and Ellissson, what distinguished the hypothetico-deductive process from
other types of science (i.e., descriptive, induction, deduction)
a) falsification
b) the development of competing hypotheses
c) repeated attempts to falsify original hypotheses
d) all of the above
e) none of the above - ANS ✔✔d) all of the above
How can one decide on whether to reject, or fail to reject, the Null hypothesis (H0):
a) compare the p-value to significant level alpha
b) compare a test statistic to a critical value
c) all of the above
,d) none of the above - ANS ✔✔c) all of the above
Say that, like Spiller and Schoner 1998 (see G&E textbook), you are interested in addressing the
potential impact of lizard predation on spider densities. You set up an experiment with multiple
enclosures where lizard density has been manipulated, and where spider density is measure
after one day of predator exposure. Which of the following is true:
a) lizard density is the dependent variable (i.e., the response) and spider density is the
independent variable (i.e., the explanatory variable)
b) spider density is the dependent variable (i.e., the response) and lizard density is the
independent variable (i.e., explanatory variable)
c) lizard density could serve as either the dependent or independent variable
d) spider density could serve as either the dependent or independent variable - ANS ✔✔b)
spider density is the dependent variable (i.e., the response) and lizard density is the
independent variable (i.e., the explanatory variable)
Same example (lizards and spiders). What could ruin your experiment?
a) replicates
b) confounding factors
c) controls
d) independence of observations
e) all of the above
f) none of the above - ANS ✔✔b) confounding factors
Say you don't have enough resources to run the experiment above properly, you decide to visit
different islands where lizard densities are known to vary and where the same communities of
both spiders and lizards exist. You select 4 islands:
, -Island A: no lizard
-Island B: low density of lizards
-Island C: medium density of lizards
-Island D: high density of lizards
Within each island, you randomly select 10 plots of 1 meter x 1 meter where you measure
spider density. You re-sample each plot three times: at the beginning, in the middle, and at the
end of the field season that spans 3 months. Plots are selected so that they are similar in slope,
aspect, and elevation. Plots are sampled at about the same time of day using consistent field
techniques.
What are your treatments?
a) spider density levels
b) lizard density levels
c) the plots
d) none of the above - ANS ✔✔b) lizard density levels
Based on the design described above (question 9), which is your "control"? - ANS ✔✔Island A
Based on the design described above (question 9), what kind of general experimental design is
this?
a) manipulative lab experiment
b) manipulative field experiment
c) observational study/natural experiment
d) none of the above - ANS ✔✔Observational Study/Natural Experiment
Exam Review
Deduction or Induction?
1. All of the ants in the Harvard forest belong to the genus Myrmica
2. I sampled this particular ant in the harvest forest
3. This ant is in the genus Myrmica - ANS ✔✔Deduction
Deduction or Induction?
1. All 25 of these ants are in the genus myrmica
2. All 25 of these ants were collected in the Harvard forest
3. All of the ants in the Harvard forest are in the genus myrmica - ANS ✔✔Induction
The scientific method is:
a) a technique used to decide among hypotheses on the basis of observations and predictions
b) a technique that involves both deduction and induction
c) all of the above
d) none of the above - ANS ✔✔c) all of the above
Creet et al. (2002) found that wolves in Yellowstone that are exposed to snowmobiles have 872
ng GC/g in their blood, whereas wolves that are not exposed to snowmobiles have 1468 ng
GC/g (GC stands for Glucocorticoid hormones). They propose to conduct a two-tailed t-test to
address the scientific hypothesis that snowmobiles may be responsible for the observed
increase stress levels in the group of wolves that is exposed to that disturbance.
,Accordingly, they formulate their null and alternative hypothesis:
(H0): The difference in mean GC between groups is no greater than what we would expect to
find by chance alone.
What would be an appropriate alternative hypothesis (HA)?
a) the presence of snowmobiles does not explain the difference between GC levels across the
two groups
b) the difference in GC levels between the 2 groups is too large to be accounted for by chance
alone and could be due to the presence of snow - ANS ✔✔b) the difference in GC levels
between the 2 groups is too large to be accounted for by chance alone and could be due to the
presence of snowmobiles
According to Gotelli and Ellissson, what distinguished the hypothetico-deductive process from
other types of science (i.e., descriptive, induction, deduction)
a) falsification
b) the development of competing hypotheses
c) repeated attempts to falsify original hypotheses
d) all of the above
e) none of the above - ANS ✔✔d) all of the above
How can one decide on whether to reject, or fail to reject, the Null hypothesis (H0):
a) compare the p-value to significant level alpha
b) compare a test statistic to a critical value
c) all of the above
,d) none of the above - ANS ✔✔c) all of the above
Say that, like Spiller and Schoner 1998 (see G&E textbook), you are interested in addressing the
potential impact of lizard predation on spider densities. You set up an experiment with multiple
enclosures where lizard density has been manipulated, and where spider density is measure
after one day of predator exposure. Which of the following is true:
a) lizard density is the dependent variable (i.e., the response) and spider density is the
independent variable (i.e., the explanatory variable)
b) spider density is the dependent variable (i.e., the response) and lizard density is the
independent variable (i.e., explanatory variable)
c) lizard density could serve as either the dependent or independent variable
d) spider density could serve as either the dependent or independent variable - ANS ✔✔b)
spider density is the dependent variable (i.e., the response) and lizard density is the
independent variable (i.e., the explanatory variable)
Same example (lizards and spiders). What could ruin your experiment?
a) replicates
b) confounding factors
c) controls
d) independence of observations
e) all of the above
f) none of the above - ANS ✔✔b) confounding factors
Say you don't have enough resources to run the experiment above properly, you decide to visit
different islands where lizard densities are known to vary and where the same communities of
both spiders and lizards exist. You select 4 islands:
, -Island A: no lizard
-Island B: low density of lizards
-Island C: medium density of lizards
-Island D: high density of lizards
Within each island, you randomly select 10 plots of 1 meter x 1 meter where you measure
spider density. You re-sample each plot three times: at the beginning, in the middle, and at the
end of the field season that spans 3 months. Plots are selected so that they are similar in slope,
aspect, and elevation. Plots are sampled at about the same time of day using consistent field
techniques.
What are your treatments?
a) spider density levels
b) lizard density levels
c) the plots
d) none of the above - ANS ✔✔b) lizard density levels
Based on the design described above (question 9), which is your "control"? - ANS ✔✔Island A
Based on the design described above (question 9), what kind of general experimental design is
this?
a) manipulative lab experiment
b) manipulative field experiment
c) observational study/natural experiment
d) none of the above - ANS ✔✔Observational Study/Natural Experiment
