Yesterday Microsoft launched Windows 7. It’s the next version of Windows, following on from Windows Vista, Windows XP, and Windows 2000. As a software vendor we had early access to Windows 7 and have been using it daily for approximately 6-8 months. Our impressions are Windows 7 is very reliable, stable, much faster than Vista, and is an upgrade we wouldn’t hesitate to recommend...

Today we released the latest update to Analyse-it, version 2.20, which includes some minor fixes and major improvements. The major improvements affect users of Excel 2007, though we recommend all users download this update for the minor fixes included.

The British government recently announced a 2.5% reduction in VAT (sales tax) on goods purchased from the United Kingdom (see where we are based). UK VAT was previously 17.5%, but from the 1st December 2008 until the end of 2009 it has been reduced to 15%.

Like many businesses, last Monday, we implemented the change.

In clearly titling this blog post, we’ve probably already revealed the answer, but... Can you spot the difference between the two rows of values in the Excel spreadsheet shown below?



Sorry, it’s a trick question, because (visually) there is no difference. The difference is how the values are stored by Microsoft Excel. The value 57 in the cell on second row is actually stored as a text string, not a number.

When does Excel store numbers as text?

When you type a value into a cell, Excel looks at what you’ve typed and decides whether it’s a valid number. If it is, the value is stored as a number, and if not it’s stored as text (a string of characters).

Considering this, how is it possible for Excel to store a value that looks like a number, as text? There are a few ways. Most common is when you copy-paste data from another application, and the application providing the data fools Excel into believing the values should be stored as text. Similarly, if you import data from a database field that contained numbers stored as text, the numbers will be imported as text. Finally, you can force Excel to store a number as text by prefixing it with an apostrophe (‘).

The side-effects of numbers stored as text

So what difference does it make? Venturing into computer science briefly, computers represent and store numbers and text values very differently – numbers are stored in a compact binary representation, and text strings are stored as a string of individual characters. The problem is that mathematical operators

Today we’re delighted to publish the second case study into the use of Analyse-it.

The case study features a national clinical laboratory in the USA that offers more than 2,000 tests and combinations to major commercial and government laboratories. They use Analyse-it to determine analytical performance of automated immunoassays for some of the industry’s leading in-vitro diagnostic device makers -- including Abbott Diagnostics, Bayer Diagnostics, Beckman Coulter and Roche Diagnostics.

Unfortunately we cannot name the end-user, or the organisation she works for, in the case study. Although she was delighted to feature in the case study, at final approval her organisation's committee preferred the names be withheld. Thankfully they have allowed us to use the case study, albeit anonymously.

In a previous post, Testing the assumption of Normality, we explained the tests provided in Analyse-it to determine if a sample has normal distribution. In that post, we mentioned that although hypothesis tests are useful you should not solely rely on them. You should always look at the histogram and, maybe more importantly, the normal plot.

The beauty of the normal plot is that it is designed specifically for judging normality. The plot is very easy to interpret and lets you see where the sample deviates from normality.

A customer contacted us last week to ask how to refer to cells on an Analyse-it report worksheet, from a formula on another worksheet. The customer often used Analyse-it's refresh feature, to repeat the statistical analysis and update the statistics, and direct references to cells on the report were being lost on refresh. 

As an example, suppose you have used Analyse-it linear regression to calculate the linear relationship between installation cost and the number of employees required, distance to the site, and the cost of machine being installed. Analyse-it would calculate the effect of each variable on the final cost, technically known as regression coefficients, which you can then use to predict installation costs for jobs in future.

You might setup a worksheet to predict and quote installation costs for future jobs. You could use an Excel formula to reference the coefficients directly from the Analyse-it report, for example:

= Employees * CostAnalysis!C17 + Distance * CostAnalysis!C18 + MachineCost * CostAnalysis!C19

By directly referencing the coefficients calculated by Analyse-it in your formula, you can be sure you’re using the exact values with no chance of error.

If you’ve used this technique before, you already know the problem.

Today we’re delighted to publish the first case study into the use of Analyse-it.

Marco Balerna Ph.D., a Clinical Chemist at the EOC (Ente Ospedaliero Cantonale) in Switzerland, used Analyse-it when replacing the clinical chemistry and immunological analysers in EOC’s laboratories.

Since the EOC provides clinical chemistry services to five large hospitals and three small clinics in the region, it was essential the transition to the new analysers went smoothly. Marco used Analyse-it to ensure the analyser’s performance met the manufacturer’s claims, to ensure the reporting of patient results was not affected, and to comply with the regulations of the EOC’s accreditation.

Last Friday we released the latest update to Analyse-it, version 2.12. Version 2.12 is a minor update providing minor fixes to issues recently reported by customers. The update is available free to everyone. 

If you're using version 2.11, and not experiencing any of the issues fixed (see the change history), then you can skip the the update if you wish. But if you're using an earlier version of Analyse-it, version 2.10 or earlier, we recommend you get the update.

Although the charts in Analyse-it are large so they’re easy to read when printed, sometimes you need to print a chart to fill the full page.
You can easily print a chart full-page, without resizing the chart, in just a few steps

We’re pleased to announce that from today we can accept payment in EUROs. You can now see prices for Analyse-it in EUROs, as well as British Pounds sterling, and US dollars (for customers in the USA & Canada). 

The EURO is now the primary currency in Europe and many of our customers have asked us to accept EUROs. We can accept payment in EUROs by VISA, MasterCard or AMEX credit card, or by cheque or wire-transfer.

One of many benefits of Analyse-it is the range of statistical charts available – charts you normally can’t create in Microsoft Excel without a lot of effort and some nifty tricks. Underneath the charts are still just standard Excel charts, and like any Excel chart you can easily change how they look. 

The options Excel offers to change the chart look are overwhelming, and not all are useful -- gradient fills, bitmap fills, 3d effects, and WordArt to name a few. Serious researchers rightly shun such effects, referring to them as chart junk – fancy effects that add nothing. More often than not these effects detract from the main purpose of the chart, often deceiving readers, rather than clearly conveying information.

Identifying what was analysed, when, and by who, is the first step in understanding any Analyse-it report. The top rows of each report provide you with this information. The statistical test used, dataset and variables analysed, user who analysed, and the date and time last analysed, are included. 

The date the report was last updated is included so you can see when reports are out of sync with changes made to the dataset. It’s also useful if you archive analysis reports and need to know when the analysis was performed. For brevity Analyse-it shows only the date, but the cell also contains the time of the last update to the report. To see the time, click the cell containing the date to activate it, and then look at the Excel formula bar to see the time (see screenshot above).

In May this year, we surveyed users of the Analyse-it Method Evaluation edition to gain insight into how we can improve Analyse-it in future. In the responses, one issue became clear: the unfiled reports feature causes confusion.

While answering a customer e-mail earlier this week, it occurred to us that some Analyse-it users don’t know how to filter data with Analyse-it. Filtering lets you restrict analysis to just a subset of your dataset, for example Females only, or females over 40 years old, and is invaluable for exploratory data analysis.

The most used distribution in statistical analysis is the normal distribution. Sometimes called the Gaussian distribution, after Carl Friedrich Gauss, the normal distribution is the basis of much parametric statistical analysis. It’s vital to ensure the samples under test have a normal distribution.

For new and occasional Analyse-it users, datasets can sometimes be confusing. Today we’ll explain why we devised the 'dataset' concept, a concept now copied by some other Excel add-ins.

A few readers have asked for more information about the book by David J. Sheskin we alluded to in the comment reply re: the Statistical test advisor, last week. The book is the Handbook of Parametric & Non-parametric Statistical procedures, by David J. Sheskin, ISBN: 1584888148.

Following our recent announcement that Analyse-it 3 is now in development, the first new feature we’d like to tell you about is the Statistical Test Advisor.

Many Analyse-it users readily admit their statistics knowledge is a little rusty, usually because it’s 10 or more since their last statistics course. Should I use the t-test, Mann-Whitney, or Wilcoxon test? The names of the tests aren’t exactly helpful, nor do they give you any clue of the assumptions that must be met to use the test.

That’s why we devised the Statistical Test Advisor.

Depending on where you’re located, the way we spell “Analyse-it” may intrigue you. We chose the name in 1997 as it sounded active, a direction to analyse it! – similar to many product names of the time.

The name has served us well and hints as to what our business and product offers. At the time we didn’t think such a simple name would cause so many headaches.