FW 471 EXAM 2 QUESTIONS AND
ANSWERS 100% PASS
Assumptions Distance Sampling - ANS 1. Animals are spatially distributed random process
2. Survey lines are randomly placed with regard to object of interest
3. All individuals on the line are detected with the certainty g(0)=1
4. Animals are detected at their initial positions
5. Measurement error is negligalbe (distance/angles measured accurately)
6. Individual sightings are independent and drawn from the same probability distribution
If g(0) does not equal one, you violated the assumptions and estimate is _____ - ANS bias
Define these constants:
A
k
w
li
L
n - ANS A = area occupied by population
k = number of lines/points surveyed
w=width area searched on each side of the transect or radius around a point transect
li=length of transect I, I=1.....k
L=total line length (sum of al li)
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, n=number of detections
Define D - ANS D = density
Define N - ANS N = population size in study area
Define Pa - ANS Pa=average detection probability for an object in sample area
Define g(0) - ANS g(0)probability of detection on the line or point (assumed to be one)
Define f(0) - ANS f(0)=probability density function of distance from the line, evaluated at a
distance of zero
muw - ANS muw=effective strip width (ESW), width at which the count represents a census
number see outside transect=number seen inside
h(0) - ANS slope of probability density function f(0)
define terms in equation for distance sampling
D-hat=n/(2Lµ-hat)
D-hat=(n/2L)((f(0)-hat) - ANS D-hat=estimated density
n=total count (sum of ni)
2L=L is total length of all transects. The 2 is used to define ESW on either side of transect
µ-hat=ESW, width at which count represents a census
f(0)-hat=estimated probability density function of distance from line evaluated at distance 0
What is the relationship between µ-hat and Pa(average detection probability) - ANS Pa=µ-
hat/w
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
ANSWERS 100% PASS
Assumptions Distance Sampling - ANS 1. Animals are spatially distributed random process
2. Survey lines are randomly placed with regard to object of interest
3. All individuals on the line are detected with the certainty g(0)=1
4. Animals are detected at their initial positions
5. Measurement error is negligalbe (distance/angles measured accurately)
6. Individual sightings are independent and drawn from the same probability distribution
If g(0) does not equal one, you violated the assumptions and estimate is _____ - ANS bias
Define these constants:
A
k
w
li
L
n - ANS A = area occupied by population
k = number of lines/points surveyed
w=width area searched on each side of the transect or radius around a point transect
li=length of transect I, I=1.....k
L=total line length (sum of al li)
1 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
, n=number of detections
Define D - ANS D = density
Define N - ANS N = population size in study area
Define Pa - ANS Pa=average detection probability for an object in sample area
Define g(0) - ANS g(0)probability of detection on the line or point (assumed to be one)
Define f(0) - ANS f(0)=probability density function of distance from the line, evaluated at a
distance of zero
muw - ANS muw=effective strip width (ESW), width at which the count represents a census
number see outside transect=number seen inside
h(0) - ANS slope of probability density function f(0)
define terms in equation for distance sampling
D-hat=n/(2Lµ-hat)
D-hat=(n/2L)((f(0)-hat) - ANS D-hat=estimated density
n=total count (sum of ni)
2L=L is total length of all transects. The 2 is used to define ESW on either side of transect
µ-hat=ESW, width at which count represents a census
f(0)-hat=estimated probability density function of distance from line evaluated at distance 0
What is the relationship between µ-hat and Pa(average detection probability) - ANS Pa=µ-
hat/w
2 @COPYRIGHT 2025/2026 ALLRIGHTS RESERVED.
