 
ENH440 [BIOSTATISTICS] WEEKLY LOG
WEEK #
(week starting)

As we move through the materials and examples, the
background colour changes from
green
to
yellow.
; (Note that green  future  is only approximate).
In this way you can see what we have already covered, and what we
should be covering next.

week #1 


week #2 


week #3
Sept 23

Displaying data in histogram, normal
(Gaussian) distribution. Nonnormal distribution examples, calculation
of mean, median, mode as indicators of central tendency.
Confidence limits
around the mean, and interpretation. Summary
examples.

Some of the PowerpointŪ slides used during
today's lecture are Here

week #4
Sept 30 
Introduction to Null Hypothesis and scientific method of enquiry.
Review of sampling theory in epidemiology: target population, random sample,
sampling error, systematic error, bias, normal error,
Introduction to
hypothesistesting and comparison of two means, rephrasing as a null
hypothesis and concept of testing the nullhypothesis (H_{0}),
rejecting/not rejecting,

Some of the PowerpointŪ slides used during
today's lecture are Here
Please note a
slight change has been made near the end related to the
standard deviation of the first group.

week #5 
Review:.
Clarification of the background to forming a null hypothesis
Part 1:
Practice with single group statistics
Part 2:
Practice H_{0}testing
using ttest. Example from bloodtesting for mercury in northern Ont.
and relation to fish consumption, rationale, comparison of calculated t vs
critical t, probability statement, and conclusion. Especially note the
importance of the denominator of the ttest and how it may be reduced by
increasing the "N"
Part 3:
Practice with Probability values 
Some of the PowerpointŪ slides used during
today's lecture are Here
Practice problems on
this material: 2, 13, 16, 17, 18, 21, 24, 25,
26, 27, 31,
 are
being added on the question page.
Answers to these problems are
shown on the
solutions page. 
week #6 
READING / STUDY WEEK 
week #7 
MIDTERM TEST 

week #8 
CANCELLED 

week #9
(Nov 4) 
REVIEW of ttest material to date.
Special case for ttest used on Paired data; what is pairing?, and why
does this offer a better result IF USED PROPERLY!
Comparison
with ttest for UNPAIRED data
Introduction
to ANOVA 
Some of the PowerpointŪ slides used during
today's lecture Here
General
practice problems
on this material from the course text:
Try p.306, Q#1, Q#2, Q#13 (Answers on page 633) I
also
recommend using the slightly more simple formulae from the lectures.
More specific practice problems on this material can be found
on the Proteus question page.
Try: # 3, 15, 19, 22,
23, 43, 49, 51, 52,
53,
(Answers to
these problems are shown on the
solutions page.)

week #10
(Nov 11) 
Contingency tables: testing the null hypothesis using ChiSquare
and Fisher's Exact Test, odds ratios and relative risk.
Applications and interpretations. 
Some of the PowerpointŪ slides used during
today's lecture Here
General
practice problems
on this material from the course text:
Try p.224, Q#2, Q#6, Q#7, Q#8, Q#9 a, Q#10 b,c,
(Answers on page 627)
You can ignore the calculation of the confidence
limits around
the odds ratio, but you should remember that if the CL
include 1.00,
you are NOT permitted to claim statistical significance
regardless of
the results of the Chisq or Fisher's Exact Test.
Also from
Chapter 9, try Q#11, Q#15, Q#16, Q#19, Q#20 b, Q#23
As before, you
may find the formulae from the lectures and the PowerPoint*
notes a little
easier to use than those included in the text.
More specific practice problems on this material can be found
on the Proteus question page.
Try: # 1, 6, 9, 20, 28, 29, 35, 38, 41, 50, 54
(Answers to
these problems are shown on the
solutions page.)
NOTE: I will be in the office Friday Nov 15
0915 to 1200 and Monday Nov 18 11301515 
week #11
(Nov 18 
Simple Regression Models for two
continuous variables; drawing the regression line, interpretation.
Testing hypothesis that slope of
regression line is zero;

Some of the PowerpointŪ slides used during
today's lecture Here
Some general concept questions on
regression can be found on p 498 etc.
of the text: # 1, #4, #5, with answers on page 643.
More specific practice
problems on this material can be found
on the Proteus question page. :
7, 8, 10, 11, 39, 40, 46, 49,
(Answers to these problems are shown on the
solutions page.).
(An error was
found in the regression example shown in class Nov 18.
It has
been corrected in the powerpoint set today, Nov 26) 
week #12
(Nov 25) 
Correlation; .. applications
and interpretation 
Some of the PowerpointŪ slides used during
today's lecture Here
Some general concept questions on
correlation can be found on p452 etc.
of the text: # 1, #13 (a, b, c), #17 (a, d), with answers on page 641.
A more specific practice
problem can be found
on the
Proteus question page. #
49. Also #39 calls for correlation to investigate
the possible relationship between the two
independent variables (after
the regression analysis explores the relationship between each of
them
and the dependent variable
separately. Finally, #48 is solved using
correlation
on select sets of data (not yet posted).
(Answers to these problems are shown on the
solutions page.). 
week 13
(Dec
2) 
Challenge: :Which method do I
use?" Review and
examples, common mistakes and assumptions to avoid. 
General review, with many
examples worked through. Please note some clarification and
additional information has been added to the question set and the
solutions page. 

Final examination (Date DEC 5th,
ENGINEERING BULDING rooms: LG/ 12, 13, 21, & 24)
If you want to see the formulae that will be supplied for the exam,
click here BUT be warned..... math
symbols vary with the computer software, browser and release #. 
_________________________
