BLAST FROM THE PAST – STOP & HAMMER TESTING

Twenty two years to this day, I was working for a scientific software company when my manager, introduced me to an unusual yet highly effective testing method – Stop and Hammer Testing. At the time, we were testing bioinformatics and material science software, some of which required the use of large IBM IntelliStation machines for 3D visualisation testing. These setups were enormous with massive monitors, specialised hardware, and testers wearing goggles to experience 3D molecular structures. It felt like stepping into a sci-fi movie, navigating through molecules as if we were part of a futuristic lab.

At one point, I was testing on an informatics product and struggled to find defects. No matter how diligently I followed the test cases, the software just wouldn’t break! A Senior Product Director passing by our test lab, noticed the situation, and casually remarked, “Boby, I first developed this product when I was a student at Harvard 30 years ago. “Keep testing, No pressure then!”

I went to my manager, and explained the situation. Instead of a conventional solution, he simply said, “Give Stop and Hammer Testing a try.”

I was intrigued. What on earth was Stop and Hammer Testing? He explained it simply:

1. Stop formal testing – Pause the structured test case execution.
2. Invite a wider audience – Bring in business users, developers, end-users, and even scientists to test the system.
3. Hit hard on the application – Actively try to break the software, uncover unexpected behaviours, and log every observation.
4. Analyse the findings – Categorise the observations into defects, usability concerns, future requirements, etc.

I was sceptical but decided to give it a go. To my surprise, it was a massive success!

Over the years, I have refined and improved this approach, and now recommend this type of testing in two key scenarios:

1. When you’re struggling to find defects – If traditional testing isn’t surfacing issues, it’s time to shake things up.
2. When you’re running out of time – This method is brilliant when you need to complete testing within tight deadlines and still deliver value.

To make the most out of this technique, follow these structured steps:

1. Define a Clear Objective of testing eg. finding defects and set a clear focus area and purpose of the testing with areas to be covered.
2. Choose a Diverse Set of Testers Business users Developers End-users Testers from different teams
3. Set Up a conference call and perform testing over the call – Brief everyone on the goal Explain the focus areas Encourage testers to interact freely with the system and other users
4. Encourage Exploratory Testing – Try different actions, input random data, and push the system to its limits Focus on real-world scenarios that users might encounter
5. Log Observations in a Structured Manner – Assign a few defect managers to categorise and document findings during the testing itself. Do not leave it for later or ask the testers to send you evidence of defects. Ensure defects are logged with clear steps to replicate. Classify issues into bugs, usability improvements, or future feature requests.
6. Review and Prioritise Once the session is complete – Review all findings. Categorise and prioritise issues for resolution.

Stop and Hammer Testing isn’t just about letting people randomly click around – it’s structured chaos. The key is to provide just enough guidance to make it productive while still encouraging creativity and unconventional thinking. This approach works exceptionally well in Agile environments where rapid feedback is essential. Instead of waiting for the usual bug reports, you get immediate insights from a variety of perspectives, often uncovering hidden defects that structured test cases might miss.

To this day, I remain grateful to my manager for introducing me to this approach. In a world that often overcomplicates software testing, sometimes a simple, back-to-basics approach can provide enormous value. If you’re ever in a tight spot, struggling to find defects, or need quick test results, remember: Stop, Hammer, and Test! 🔨

Please note “Stop and hammer testing” is another way of referring to the “Rebound Hammer Test”, a non-destructive method used in construction to assess the compressive strength of concrete by measuring how far a spring-loaded hammer rebounds after striking the concrete surface; essentially, the higher the rebound, the stronger the concrete is considered to be; also known as the “Schmidt Hammer Test” due to its inventor, Ernst Schmidt.