Code, Crime, Complexity: Analyzing software with forensic psychology | Adam Tornhill | TEDxTrondheim

Summary

In this insightful talk, a software developer explores how blending psychology with programming can enhance the software development process. Drawing inspiration from forensic psychology, the speaker demonstrates how geographical offender profiling techniques—used to identify crime hotspots—can be applied to software development. By analyzing version control data, developers can pinpoint areas of code most prone to bugs, improving quality with minimal effort. The speaker emphasizes that understanding programmer behaviors and their impact on code can help optimize both software quality and team dynamics, offering valuable insights for both developers and managers.

Takeaways

• 😀 Programming is not just about machines but understanding human thinking, reasoning, and communication, which is why psychology is important in software development.
• 😀 The majority of a software developer's time is spent understanding and modifying existing code, highlighting the challenge of complex software systems.
• 😀 As software projects scale and are worked on by multiple developers, there is often no clear holistic understanding of the entire system, creating inefficiencies.
• 😀 Forensic psychology, particularly geographical offender profiling, can provide insights into software development by identifying patterns in complex data.
• 😀 Geographical offender profiling uses crime scene locations to predict an offender's home base by analyzing patterns in their movements and the environment.
• 😀 By using a similar approach to criminal profiling, software developers can focus on 'hotspots'—areas in the code where issues are most likely to occur.
• 😀 Software systems can be visualized as a 'geography of code,' where different parts of the system are represented by buildings of varying sizes based on their complexity.
• 😀 Spatial movement data from version control systems allows developers to track changes in the code and identify areas that are most frequently modified or problematic.
• 😀 Hotspot analysis in software shows that only a small portion of the code often accounts for the majority of bugs, making it a prime area for improvement.
• 😀 By focusing on the identified hotspots in software, developers can significantly improve quality with minimal investment, addressing the most defect-prone parts of the code.
• 😀 The concept of profiling can extend beyond software code to managing team dynamics, with tools for tracking developer communication and knowledge distribution, helping managers identify risks like knowledge gaps and abandoned code.

Q & A

What inspired the speaker to pursue psychology alongside software development?

The speaker was inspired to pursue psychology to better understand human behavior and communication, as software development is not just about programming machines, but also about how we think, reason, solve problems, and work with others.

What is the main challenge in software development that the speaker highlights?

The main challenge is understanding existing software systems. Most of the time, developers spend more effort trying to understand what the code does, rather than writing new code, which can be especially difficult as software scales and involves multiple teams.

How does geographical offender profiling relate to software development?

Geographical offender profiling, which involves analyzing crime scene locations to predict a criminal's base, is used as an analogy for software development. The speaker suggests applying similar techniques to software by identifying 'hot spots' in code—areas where complexity and frequent changes overlap.

What is the concept of 'hot spots' in geographical offender profiling?

In geographical offender profiling, hot spots are areas where the criminal repeatedly commits crimes, and these locations are believed to be near the criminal's home base. This concept is used to predict where an offender is most likely to be based on their pattern of criminal activity.

What is the significance of 'hot spots' in the context of software development?

In software development, hot spots refer to areas of code that are both complex and frequently modified. These parts of the code are more likely to contain defects, and focusing efforts on these areas can significantly improve the overall quality of the software.

How does the version control system help in identifying hot spots in code?

The version control system tracks changes made to the code, including who made the changes and where in the code they occurred. This data can be analyzed to identify areas of the software that are frequently modified, helping to pinpoint hot spots where code quality may be more prone to issues.

What was the outcome of the case study performed on an open-source software project?

The case study on a popular open-source database project revealed that hot spots—defined by areas of high complexity and frequent code changes—were responsible for the majority of defects in the system. Despite comprising only 4% of the code, these hot spots contained 72% of the defects.

How can identifying hot spots improve software quality?

By focusing on improving the code in the hot spots, which are prone to defects, developers can dramatically reduce the number of bugs in the system with minimal effort, leading to a significant improvement in the overall software quality.

What additional insight does the speaker provide about the future of software development techniques?

The speaker suggests that new research and tools, such as communication diagrams and version control data analysis, can help developers and managers identify knowledge gaps, dependencies, and the most critical areas of code, offering potential solutions for future improvements in software development.

How does geographical profiling help in criminal investigations, and what is its limitation?

Geographical profiling helps locate a criminal's home base by analyzing the locations of their crimes. However, it has limitations, as it only provides probabilities, not certainties, and is more effective in certain cases than others. For instance, the Jack the Ripper case showed that profiling could point to a likely location but not definitively identify the offender.