Category Archives: Quality Management

Eliminating biases in A/B testing

A/B testing is a powerful customer-driven quality practice, which allows us to test a variety of implementations and find which works better for customers.  A/B testing provides actual data, instead of the HIPPO.

The folks at Twitch found that the users in the test cell had higher engagement than the control group. They found that this higher engagement came from factors other than the new experience, which might cause a cognitive bias in their results.  Factors like the Hawthorne effect and new users break the randomness for the experiment.

They adjusted the data to reduce the impact of these effects, and provided a great case study on how they did it

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Testing Myopia

Horse and Buggy by Patrick Henson

Horse and Buggy by Patrick Henson

In school, marketing class. Concept of marketing myopia, where companies focus too much on the product they are currently producing. This near-sightedness keeps businesses from adapting to changing technology and market conditions. The classic example is the buggy whip manufacturing company.

The invention of the automobile is a threat to buggy whip producers, because the automobile technology will eliminate the need of buggy whips. If, instead, they see themselves as “transportation initiation” companies, then the automobile is an opportunity to serve a new set of customers, those who don’t want to hand crank their engines.

The idea behind marketing myopia is to take a step back, take a longer view of your product. A good way to do this is to think about what service you provide, rather than what product you produce.

What does this have to do with software testing and quality leadership?  Well, sometimes we get focused on our tools and processes. These tools of the trade are an important part of our craft, but the larger organization is not really looking for great automation suites, exploratory tests, or exit criteria. We talk about bug counts and severities. We talk about test pass/fail rates. We talk about code coverage.

Our product is testing, test results, and bug reports.

But, what service do we provide?  Why does the organization “purchase” testing?

Our organizations hire us to provide a service, that service is confidence. Confidence that our products will meet or exceed customer expectations. Confidence that our systems will be secure, available when needed, and perform as advertised.  Confidence that when its time to ship that the product is ready to ship.

How does taking a different look at our role influence what we do? What do we do differently if we are in the confidence business rather than the testing business?