Dr. Mona Hassan Ahmed Hassan Prof. Biostatistics. Computer Utilization . for Diabetes Epidemiology. Statistical Software . What to do before sitting to PC?. How to generate and interpret results?. Objectives. Data Coding. Transformation of qualitative information into Numbers OR
for Diabetes Epidemiology
What to do before sitting to PC?
How to generate and interpret results?
Transformation of qualitative information into
Either the information is transferred from the original record to a “coding sheet”
1. Date of Interview
2. What is your date of Birth?
3. What sex are you?
Male (m) Female (f)
4. What is your marital status?
Single (1) Married (2)
Widowed (3) Divorced (4)
5. What is your height (cm)?160
6. What is your weight (kg)?58
1st placeScales of Measurement
Ordinal Rank Order
Rating on a
0 to 10 Scale
Ratio Time to Finish, in
Mode Median Mean
If Mean > Median Positive or right skewness
(long right tail)
It arises when the mean is increased by some unusually high values
Mean Median Mode
If Mean < Median Negative or left skewness (long left tail).
Negative skewness occurs when the mean is reduced by some extremely low values.
Developing and Testing a Hypothesis
differences in frequency distributions of nominal level variableschi-square
associations or correlations between variables, bivariate correlations
differences between groups with respect to the distribution of interval/ratio level data.t-tests
Any Statistical software
1- Wild codes check (invalid codes)
2- Completeness check:ensure that
all cases collected are
represented in the data file