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submitted two impressions). Be certain that Additionally, encouraging students to choose
no lab group gets two copies of the same continuous features over categorical ones will make
impression, or their own impressions. If separation of characters via multivariate analysis
impressions were removed you will have just easier.
enough, but the exact number is not critical.
6. Tell your students that these impressions are MULTIVARIATE ANALYSIS
from patrons of the bar where John Gretzky This lab contains a section on Multivariate Analysis.
claims to have been bitten. In addition, give To aid you with these calculations a Microsoft
each lab group an impression from the Excel spread sheet is available for download at
car crash victim (included with the kit) to www.LyleAndLouise.com. Visit the “Downloads”
determine if she was the biter. page, create/login to an account, and register your
product to download the supplemental material for
Do not give students the photograph immediately this module.
as students will often look for common features
between the photo and the impressions and This spreadsheet will calculate the percent
come to a visual, subjective conclusion instead difference of each of the samples from the photo.
of a wellmeasured objective one. Instead, have Smaller values indicate a closer match. To be legally
them first develop characters to separate all useful, values should be under 5%.
of the samples collected from the bar patrons.
6 THE MYSTERY OF LYLE AND LOUISE
