OBGYN MSc Stat Module (2016-2018) : Introduction to StatPgm
Introduction 1 Probability(z&t) 2 One Group 3 Two Groups 4 MetaAnalysis 5 Tests 6 Graphics 7 Utilities

What is StatPgm

StatPgm consists of a number of web based computer programs that performs all the statistical calculations used in the module.

Why StatPgm The reasons of providing StatPgms to the students are as follows.

  • Only procedures necessary for the modules are included, to reduce the need for searching for the correct program.
  • The programs are in the form of a web page, integrated with web based course contents, so they are easy to use during study
  • Data input is simplified to reduce the learning curve, so the students can focus on the statistics
  • The output is simplified to focus the students on the most basic and essential part of interpretation

Does StatPgm have any issues Students should be aware of the following issues

  • The program is designed for teaching at the MSc level, so many results desired by the professional statistician have been left out. The programs are therefore insufficient for long term use by professional researchers
  • The calculations are carried out by the CU server, so the programs will not work unless the computer is connected to the Internet.
  • There are minimal error checking of the data entered. If the data contain errors or not formatted correctly, the program will behave unpredictably.
  • The server processor may be different to operating systems of commercial packages, so have different rounding errors. The results produced are therefore sometime minimally different.
  • The graphics generated are in the png format, so may distort if the bitmap is enlarged or reduced. The user therefore has to consider and define the size of the bitmap at the time of creating it.
  • In calculating sample size, the default values of p=0.05 and power=0.8 are provided. In defining confidence intervals, the default 95% confidence interval is provided. These default values are most commonly used in clinical research, and are provided to reduce the input students have to consider. However, students have no options to change these settings.

Are there other statistical and graphics programs that students can use

All StatPgm programs are modified from those on the Dept. O & G statistical website StatTools. The programs on that site are designed more for researchers and statisticians, so more options and output are provided. However there are over 150 pages on that site, so students will have to search and find the specific program needed.

SPSS is probably the most popular and easy to use commercial statistical package available, but is expensive unless the student has a university license. The older versions do not have sample size estimations and the graphic facilities are difficult to use. More recent versions may be better

STATA, MatLab, and SAS are the most comprehensive and powerful packages preferred by mathematicians and statisticians. The learning curve is however steep, and the packages very expensive.

All graphics produced by MacroPlot in StatPgm can also be produced by a combination of procedures in Excel and Powerpoint, and in many instances it is easier to use Excel than StatPgm

What will the rest of this page discuss

The rest of this page will discuss how to use the StatPgms, how to format the data entry, and a brief description of what the results represent. Detailed discussion on theories, when to use the procedures, and other statistical considerations will be discussed in the content pages for individual research situations.