Power Analysis Surge

December-February (and generally March) is Summer in the Southern Hemisphere. It can get pretty hot even in the more temperate southern states (= northern states in the Northern Hemisphere). Today, the last day of 2015, has an expected top of 40 Celsius, which is 104 Fahrenheit and a nose-peeling 313.5 Kelvin!

Summer is also the start of the Australian Academic Year, and Grant Season, where everyone is looking for Statisticians (who are in swimming pools or pool halls) to run power analyses for them. With no statisticians to be found, it’s off to the library and borrow whatever randoms they can find, or use one of the free web packages, which often works out like a home haircut.

There’s great specific software such as PASS http://www.ncss.com and NQuery Adviser & Nterim  http://www.statsols.com/products/nquery-advisor-nterim/

They’re not cheap (but neither are grants!), and aid professional statisticians as well.  There’s R of course, and the excellent menu-driven power and sample size routines in SAS and Stata.

But first  define the differences you’re expecting, based on the actual Literature as well as Clinical Judgement, and always see a Statistician!

Wisdom of the Cloud

Many summers ago when I started out in the Craft, I could log onto the trusty DEC-20 literally anywhere in the world, and use SPSS or BMDP to analyse data. Nowadays, I have to have IBM SPSS or Stata installed on the right laptop or computer, and bring it with me, wherever I may roam, and wonder dreamily  if I could just access my licensed stats packages from anywhere, like a library, a beach, a forest, a coffee shop.

One option would to subscribe to a stats package in the Cloud! Iin terms of main line stats packages, https://www.apponfly.com/en/ has R (free plus 8 euro’s ($A12.08) per month for platform, NCSS 10 at 18/27.19 per month + platform, IBM SPSS 23 Base 99/149.54 ditto and Standard (adds logistic regression, hierarchical linear modelling, survival analysis etc) for 199/300.59 per month + platform.

Another option, particularly if you’re more into six sigma / quality control type analyses, is Engineroom from http://www.moresteam.com at $US275 ($A378.55) per year.

Obviously,  compare the prices against actually buying the software , but to be able to log in from anywhere, on different computers, and analyse data,  sigh, it’s almost like the summer of ’85!