Q. What do I need to run ESCI?
A. You need a licensed copy of an appropriate version of Microsoft Excel. ESCI delta was developed in Excel97. It may run in later versions, although probably not Excel 2007. Later modules were developed in Excel 2003, and may run in earlier versions of Excel. Some modules are labelled as being compatible also with Excel 2007; modules not labelled in this way probably will not run properly in Excel 2007. (Excel 2007 introduces problems: It runs very slowly, does not support full compatibility with earlier versions, and omits important features. Prefer to use Excel 2003 if at all possible.)

Q. File sizes?
A. ESCI-delta downloads as a 1.1MB zipped file that self-extracts simply by double-clicking. It unzips into a folder containing 6 Excel workbooks, total size 3.5MB. The largest of these is CIdelta, at 1.8MB. Other modules are not zipped, and are smaller files: ESCI JSMS is 229KB, and ESCI Ustanding Stats is 260KB.

Q. What prompted ESCI?
A. I have long been interested in the trickery and misconceptions of NHST (Null Hypothesis Significance Testing) and the damage it does to research. What statistics teacher is confident his or her students (or colleagues!) really understand NHST? The literature is full of examples of NHST being misunderstood, and null hypotheses being unjustifiably accepted. There has to be a better way. I have worked on statistics education and statistical cognition projects: see my own site. Now psychologists are at last being instructed to use confidence intervals much more. Effect size measures must be reported, and meta-analysis is encouraged.

In November 2000 Bruce Thompson (Texas A&M; then editor of Educational and Psychological Measurement) arrived at La Trobe for two months as a Distinguished Visiting Fellow. Mike Smithson came down from the Australian National University and gave a workshop on confidence intervals based on non-central distributions. Sue Finch and I started to write the CI Primer paper that eventually appeared in August 2001 EPM. The six ESCI-delta simulations were built to illustrate that paper.