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Teaching Guide
Activity 2 Inferring Height From Bone Length
 
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ANSWERS

Part 1-Inferring Height from Femur Length
Analyzing Your Results

  1. How accurate were you in inferring height from femur length? Explain.
    (Answers will vary but expect a variance of up to 5 cm)
  2. Were factors such as gender and race taken into account in this computation? Explain.
    (No. Only a single computation that did not include gender or race differences was used in estimating height)
  3. How might the accuracy of this calculation be improved?
    (The calculation used was most likely developed for white males. So although it can be used for other groups, it may not be accurate across the range. In order to increase the accuracy of individual measurements, one would need to develop custom equations for each sex and race (as seen later in the exercise.))

Part 2-Inferring Height from Humerus Length

Analyzing Your Results

  1. How accurate were you in inferring height from humerus length? Explain.
    (Answers will vary but should have less of a variance than observed in previous exploration)
  2. Were factors such as gender and race taken into account in this computation? Explain.
    ( Only a subject's gender was taken into consideration when estimating height)
  3. How might the accuracy of this calculation be improved?
    (As with the previous exercise, one would need to develop additional computations that include anatomical variance based upon race)

Part 3-Inferring Height from Tibia Length

Analyzing Your Results

  1. What was an advantage in using the tibia method for determining height?
    (Variances for both gender and races were included in the computation)
  2. What were the disadvantages for using the tibia method for determining height?
    (The tibia may be more difficult to measure. Data was not given for the Mongoloid female computation. There were only three racial categories from which to select.)
  3. Were factors such as gender and race taken into account in this computation? Explain.
    (Yes - However, the races were limited to three stocks and no data was offered for the Mongoloid female computation.)

Compose Your Own Regression
Select easily measured structures of your body (such as lower arm, fingers, foot). Then compose a calculation that could be used to infer a person's height from the length of these body parts. Compare and contrast your regression to those given for femur and humerus. Which is more accurate or consistent in obtaining heights from part length?
(Measuring the length of bones in the hands and feet is not as effective in inferring height as leg and arm bone length. Though related, the former is much more variable.)

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