Scatter diagram – how handy is that?

Steve DaumScatter diagrams: a scattered approach? Steve Daum shows how this simple tool establishes support for understanding the correlations (and non-correlations) among factors.

In recent work, I’ve been thinking about the use and application of scatter diagrams. You have probably seen these. Here are some examples:

When you look at a scatter diagram, you are testing a theory. Statisticians call this testing a hypothesis. These scatter diagrams compare two variables: one variable on the horizontal or x-axis and a different variable on the vertical or y-axis. The theory you are testing is that there is no significant correlation between these two variables.

The quick answer to the question Is the theory correct? can be found by looking at the slope of the line. The flatter or more horizontal the line is, the more comfortable you can be that your theory is correct – that is: there is no significant correlation between these two variables. The steeper the slope, either downward or upward, indicates that your hypothesis is not correct. That is there does appear to be correlation between these variables. However, like almost everything with statistics, the quick answer does not tell the whole story.

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Seeing your goals—with charts

Steve DaumWhile new year’s resolutions may already be long forgotten by many, those who are committed to personal goals continue to try to keep on the path to reach these goals early in the year. Good news: PQ Systems can help!

As we know from commercial applications of charting techniques, it is always far easier to garner information from numbers when they are illustrated visually, in charts or graphs. Even photos can help clarify meanings: A Melbourne, Australia, suburb trained volunteers to measure litter on the streets, giving them photos to support understanding of operational definitions of litter. (One cigarette butt in the gutter was not considered litter; two or more, or those on the sidewalk, were.)

So we have some ideas about supporting your personal goals for 2014 with visual use of data—a specialty of PQ Systems.

Charting data related to weight loss is commonplace, of course. Services such as or Fitbit help to keep a running chart of weights entered daily, over a period of weeks, months, or years. Even crude hand-drawn charts make the point and demonstrate trends of weight loss or gain.

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What’s blowin’ in the wind

Steve DaumMost of us are aware of the seismic shift towards carrying smart phones, tablets, and other always-connected devices. We have these pretty much everywhere we go. It can be easy to forget how different this environment is from just a few short years ago. Today, the possibility that you might be unreachable for some portion of the day is becoming more and more remote. Not having access to information on the Internet is also becoming a thing of the past.

Many of us have spent our careers using desktop computers, supplementing our primary work with word processing, spreadsheet, database, and analytical software. An interesting question is how this new environment will impact our use of traditional business software. Will we drift away from our desktop software? Will smart phone based software grow into the powerful, feature rich applications we have become accustomed to?

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Taking your charting skills home: KPIs and health maintenance

Steve DaumCharting data is not just for the shop floor any more, as we have long discovered. Measuring outcomes for healthcare, banking, education, and other environments has become commonplace. What about taking your charting skills home? Key Process Indicators can help to evaluate weight gain/loss, exercise patterns, and more, as this piece by Steve Daum demonstrates.

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Separate your charting and data analysis tools from your enterprise tools

Steve DaumOnline debate rages about whether potatoes and onions should be stored together, with the “no” side saying they both give off gases that accelerate spoilage, and the “yes” followers asserting that it makes no difference. Whether you agree or disagree, you can follow the underlying concept: some things do need to be separated in order to perform at their best. (Hence the practice of assigning twins to separate classrooms, perhaps.)

An important principle in software development is known as separation of concerns. The idea is that different concerns should be handled by different bodies of source code. For example, one body of source code should focus on saving and retrieving data from a database. A different body of code should focus on doing statistical calculations; these two concerns should never be mixed in the same body of source code. When this principle is violated, the source code is sometimes described as having a “code smell” which is not a good thing. Even worse than potatoes that smell like onions.

User requirements for software change all the time. They are dynamic. If you have source code nicely compartmentalized, you will be more nimble at stringing it together to meet some new user requirement.

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