Analysis of Class Database Survey: Types of Data, Sampling and Assessing Bias
1) Consider the survey we have at hand. It was designed to harvest a plethora of measurements to
better understand the metrics of High School Students in Ontario in general.
a) Let’s say you now want to use this survey (as is) to sample High School students in Ontario.
You perform a Multi–stage sample and wind up choosing Loyola as a site for sampling.
You contact the school administration and receive the following information to help you
determine any and all of the amount of each “type” of student you intend to select:
M:F Ratio = 44:56 Average age: 15.7 yrs
Median Age: 15.5 yrs
# Grade 9’s 271
# Grade 10’s 328 You can estimate any other demographic you
# Grade 11’s 220 like and use this in your sampling technique
# Grade 12’s 138
PIP students 18
Note: You will have access to any and all information and equipment necessary to do this sampling
(provided it can be found at the school). Funding for supplies and a staff of two volunteers will be
provided for you.
i. Devise a sampling strategy that combines both systematic and stratified sampling
techniques. Explain this strategy in detail. (2)
ii. Devise a sampling strategy that is both random and systematic. Explain your strategy in
detail (2)
iii. A colleague of yours tells you that they would not use any of the above strategies.
Instead they suggest the following:
1. Stratify the population as follows:
Grade Total # of classes Classes Sampled
9 11 5
10 14 5
11 8 5
12 6 5
PIP 2 1
2. Randomly choose the required number of classes by drawing their teacher’s
names ‘out of a hat’.
3. Sample the entire class.
4. Have the teachers sort the survey’s alphabetically.
5. Choose every other survey and those remaining surveys become your sample.
Explain two problems that exist with this strategy and then describe how you could use
their framework to effectively perform a random, stratified, and systematic sample.