A comparison of two real-world applications
Machine learning (ML) and deep learning (DL) both let computers learn patterns from data, but they suit different problems. In traditional ML, people choose the features (the data characteristics that matter) and an algorithm such as linear regression, a decision tree, or a support vector machine learns from them. Deep learning is a subset of ML that uses neural networks with many layers to discover useful features directly from raw data. DL usually needs far more data and computing power, while simpler ML models work well with smaller datasets and are faster to train and easier to explain. This report examines one example of each from the lesson: house price prediction using linear regression (ML) and machine translation using Transformer models (DL). For each, it explains why the chosen approach fits and why the other does not.
Property tax offices and appraisers commonly use regression-based mass appraisal models to estimate the value of thousands of homes at once. Inputs are well-understood property attributes: square footage, number of bedrooms and bathrooms, lot size, age of the home, and neighborhood. Online home-value estimators and real estate analysts use the same family of techniques to price homes against comparable sales.
A deep neural network would add complexity without clear benefit. With tabular data and well-chosen features, deep models often perform no better than simpler ones, they need more data and tuning to avoid overfitting, and their reasoning is difficult to explain (the “black box” problem). That lack of transparency is a serious drawback when the result affects someone’s tax bill or loan decision.
Google Translate moved from phrase-based statistical methods to neural machine translation in 2016 (Wu et al., 2016), and modern translation systems rely on Transformer architectures (Vaswani et al., 2017). The same technology underlies the large language models used in many chat and writing tools. These systems translate text between many languages in real time.
A traditional ML model such as logistic regression or a decision tree would require engineers to define features for language by hand, such as word counts or fixed phrases. Those features cannot capture long-range context, ambiguity, or the huge variety of sentence structures, so translations would be literal, awkward, and often wrong. Hand-built features simply do not scale to the complexity of human language.
| Factor | House price prediction (ML) | Machine translation (DL) |
|---|---|---|
| Data type | Structured, tabular | Unstructured text |
| Feature definition | Chosen by humans | Learned automatically |
| Data needed | Moderate | Very large |
| Computing cost | Low | High |
| Explainability | High | Low |
Deep learning is not automatically better than machine learning. The right choice depends on the problem. When features are known, data is structured, and decisions must be explained, simple ML models like linear regression are efficient and trustworthy. When the input is complex and unstructured and the patterns are too intricate to define by hand, as with language, deep learning is the better tool despite its cost and opacity. Matching the method to the problem, rather than choosing the most advanced technique, is the key lesson for anyone leading AI-enabled work.
Vaswani, A., Shazeer, N., Parmar, N., Uszkoreit, J., Jones, L., Gomez, A. N., Kaiser, L., & Polosukhin, I. (2017). Attention is all you need. Advances in Neural Information Processing Systems, 30.
Wu, Y., Schuster, M., Chen, Z., Le, Q. V., Norouzi, M., et al. (2016). Google’s neural machine translation system: Bridging the gap between human and machine translation. arXiv:1609.08144.
Course lesson: Machine Learning vs. Deep Learning (2.3 Assignment).