Ever wondered how AI systems learn to distinguish between a cat and a dog with such accuracy, or how inappropriate content gets filtered online? Often, the secret ingredient is a "Human in the Loop" (HITL).
Simply put, Human in the Loop refers to the crucial role of human intervention in an automated or AI-driven process. This involvement is designed to:
While the long-term vision of Artificial General Intelligence (AGI) — where machine intelligence might surpass human capabilities — is a topic of discussion, today's most advanced AI products, especially those facing consumers, are heavily developed with HITL pipelines. From data engineers managing information quality to machine learning (ML) scientists designing new algorithms, human feedback is integral to augmenting machine intelligence and achieving high-quality, reliable results.
The need for HITL in AI stems from several fundamental challenges related to data and model behavior:
Essentially, the processes of data engineering, model training, and AI application deployment are all carefully managed with human judgment and interaction to control how data is processed, how models learn, and how AI applications ultimately behave.
Several prevalent approaches describe how humans are integrated into AI systems:
In active learning, humans are primarily involved in data processing tasks, typically labeling and annotating data. Machines control most of the learning process, and they strategically select the most informative or ambiguous data points that require human intervention for clarification.
The machine trains the model and can ask human agents to identify features relevant (or irrelevant) to the model's learning. Manually annotating an entire massive dataset is often time-consuming, expensive, and impractical in real-time. Active learning simplifies this by having the learning algorithm pinpoint specific data points or features that are most critical for improving the model. This enhances training data quality and diversity, helping the model generalize better.
Active learning with human intervention is a form of semi-supervised learning, where not all data labels are available initially but are acquired during the learning process itself. This contrasts with supervised learning (all data labeled) or unsupervised learning (all data unlabeled).
An AI used in medical imaging might flag ambiguous areas on a scan that it cannot confidently classify. A radiologist (the human in the loop) then reviews these specific areas, provides the correct label (e.g., "benign" or "malignant"), and this feedback helps the AI learn and improve its accuracy on similar future scans.
Interactive machine learning (IML) involves humans directly and iteratively training, improving, and teaching AI models to enhance their performance. Early IML implementations focused on improving the classification performance of classical AI methods like Decision Trees. Later, the focus shifted to guiding the classification boundaries of AI models.
For instance, a human agent might examine a confusion matrix (a table that visualizes a model's prediction accuracy by showing correct vs. incorrect classifications) from multiple AI classifiers and devise a strategy to combine them effectively. In this scenario, the combined model — an "ensemble" of classifiers, where multiple models work together — is optimized through retraining based on human insights.
In modern IML, humans and machines can take on various roles. Humans might validate model predictions during training, guide the model's learning path, or focus solely on data labeling. Essentially, IML is any process where human interaction generates useful artifacts to improve model training and performance. This requires an interface for human-machine interaction and an iterative learning methodology.
A content recommendation system on a streaming service uses IML. When you "like" or "dislike" a movie suggestion, or choose to ignore it, your interactions provide direct feedback. The AI uses this feedback to interactively refine its understanding of your preferences and make better recommendations in the future.
Machine teaching is an AI paradigm where a human "teacher" — often a domain expert who may or may not have deep machine learning knowledge — controls and guides the learning process of an AI model. The core idea is transfer learning, where the human expert imparts their knowledge to the machine. This is particularly useful when labeled data is scarce or unavailable.
In practice, it looks like this:
A significant category within this is Reinforcement Learning from Human Feedback (RLHF). RLHF differs from some standard Machine Teaching approaches in how humans influence the model. In RLHF, humans typically guide the model's behavior by providing feedback on its actions or by shaping its reward system, which in turn guides its learning process. This is common in agentic AI and Large Language Model (LLM) use cases.
(Related reading: chain of thought prompting explained.)
A cybersecurity expert teaches an AI to identify new types of sophisticated phishing emails. The expert provides the AI with a curated set of recent phishing examples and benign emails, highlighting the subtle linguistic cues, suspicious link structures, or sender impersonation tactics that characterize the new threat. This expert-guided curriculum helps the AI learn to detect these specific attacks more effectively than it might from raw data alone.
In practice, many modern HITL paradigms combine elements of Machine Teaching (with IML often considered a subset) and RLHF, especially for advanced AI applications.
Incorporating humans into the AI loop offers significant advantages but also presents challenges:
Benefits:
Challenges:
Human in the Loop is not just a temporary measure but a fundamental aspect of developing robust, reliable, and responsible AI systems. While AI technology continues to advance, the need for human insight, judgment, and oversight remains critical for:
The collaboration between human intelligence and machine capabilities is key to unlocking the full potential of AI safely and effectively.
See an error or have a suggestion? Please let us know by emailing splunkblogs@cisco.com.
This posting does not necessarily represent Splunk's position, strategies or opinion.
The world’s leading organizations rely on Splunk, a Cisco company, to continuously strengthen digital resilience with our unified security and observability platform, powered by industry-leading AI.
Our customers trust Splunk’s award-winning security and observability solutions to secure and improve the reliability of their complex digital environments, at any scale.