HCC 3030 · Week 2

AI Technologies 101:
A Map of the Field

Rules, search, machine learning, neural networks, foundation models, robotics, and the economy underneath them.

Opening question

Which of these systems count as AI?

Route plannerFraud scoreRecommenderIndustrial robotChatbot

All five can count. They solve different problems with different combinations of rules, search, learning, and control.

Start with the whole stack

Every AI output sits on layers of technical and economic choices.

01

Data

What examples, labels, records, media, and feedback shaped the system?

02

Model

What architecture and training objective turn inputs into outputs?

03

Compute

Which chips, data centers, energy sources, and networks make it run?

04

Product

What context, tools, defaults, permissions, and safeguards surround it?

05

Market

Who owns the stack, sets the price, captures value, and bears the risk?

The AI umbrella

AI is a field of approaches, not a synonym for language models.

Explicit structure

Rules & knowledge

Represent facts, constraints, and logic so a system can infer conclusions.

State spaces

Search & planning

Explore possible moves or action sequences to reach a goal.

Examples

Machine learning

Fit patterns from data to classify, predict, rank, or detect.

Representations

Deep learning

Use multilayer neural networks to learn useful features at scale.

Feedback

Reinforcement learning

Learn a policy for sequential decisions from rewards and consequences.

World interaction

Robotics & embodied AI

Connect perception, planning, and control to physical systems.

Three ways to produce intelligent behavior

Different paradigms put the intelligence in different places.

01

Reason over structure

Humans define states, rules, goals, constraints, or a knowledge base.

Expert systems · theorem proving · graph search · scheduling
02

Learn from data

An algorithm fits parameters that make useful predictions on examples.

Regression · trees · neural networks · recommenders
03

Optimize through feedback

An agent chooses actions, observes consequences, and improves a policy.

Game playing · robotics · resource control · personalization
Capabilities are not roles

Modern AI systems can sense, predict, generate, decide, and act.

Perceive

Recognize patterns in text, images, audio, video, or sensor data.

Interpretation

Classify

Assign a label, category, state, or risk group.

Categorization

Predict

Estimate an outcome, value, demand, or future condition.

Forecast

Rank

Order cases, options, documents, or people by a score.

Attention

Generate

Create language, images, audio, video, code, or plans.

Proposal

Act

Call tools, send messages, transact, allocate, or control.

Execution
Machine learning in one sentence

The system learns a mapping from examples instead of receiving every rule by hand.

Input
What the system can observe

Pixels, tokens, sensor readings, records, clicks, or prior actions.

Output
What the system is trained to produce

A class, number, ranking, action, or probability distribution over possible next tokens.

Where the learning signal comes from

The training setup determines what patterns a model can learn.

Supervised
Inputs paired with labels or targets
Spam detection · price prediction · diagnosis support
Unsupervised
Structure inferred without target labels
Clustering · anomaly detection · dimensionality reduction
Self-supervised
Targets created from the data itself
Next-token prediction · masked inputs · representation learning
Reinforcement
Rewards from actions and consequences
Control · games · sequential optimization
The machine-learning workflow

Most ML failures begin before the training loop.

01

Frame

Define the decision, target, baseline, and cost of error.

02

Represent

Choose examples, labels, features, sampling, and time window.

03

Split

Separate training, validation, and test data before tuning.

04

Fit

Train candidates and tune only with permitted information.

05

Evaluate

Compare with baselines across groups and deployment conditions.

06

Monitor

Watch drift, failures, feedback loops, cost, and human response.

Leakage: the model receives information during development that would not exist at the moment of real-world prediction. The score looks excellent because the test is no longer honest.
The model toolbox

Model choice should follow the data, task, and operating constraints.

y = wx + b

Linear & logistic models

Fast, stable baselines with coefficients that can be inspected.

Strong fit: structured data, modest complexity, explanation needs
if · then

Trees & ensembles

Capture nonlinear interactions and mixed feature types effectively.

Strong fit: tabular prediction, ranking, risk scores
K(x, x′)

Kernel & nearest methods

Use similarity or transformed feature spaces without deep networks.

Strong fit: smaller datasets, clear distance or margin structure
● ● ●

Neural networks

Learn representations from high-dimensional, unstructured data.

Strong fit: vision, audio, language, multimodal data, scale
Classification is a decision pipeline

A threshold turns a model score into a real consequence.

0.00
1.00
Decision threshold = 0.70

Lowering the threshold catches more positives but usually creates more false alarms.

Precision

Of the cases flagged, how many were actually positive?

Recall

Of the real positives, how many did the system catch?

Specificity

Of the real negatives, how many did it leave unflagged?

Calibration

Does a score of 0.70 correspond to roughly a 70% event rate?

Not every ML problem is classification

Different task families demand different evidence.

Regression & forecasting

Predict a number or future value. Compare MAE or RMSE against a credible baseline and respect time order.

Can it beat “same as last week”?

Clustering

Group cases by similarity without target labels. A cluster is a mathematical pattern, not automatically a meaningful social category.

Does the grouping remain useful and stable?

Dimensionality reduction

Compress or visualize high-dimensional structure. The projection can distort distance and neighborhood relationships.

What information did the projection discard?
!

Anomaly detection

Find unusual cases when labeled failures are rare. Unusual does not mean wrong, harmful, or fraudulent.

Who investigates the alert?
Sequential decisions change the problem

Reinforcement learning optimizes behavior through delayed feedback.

Environment
Agent
policy π(a|s)
action at
Credit assignmentWhich earlier action caused a later outcome?
ExplorationWhen should the agent try an uncertain action?
Reward designWill optimizing the proxy produce the behavior we actually want?
SafetyHow can the system learn without causing unacceptable harm?
Two phases, two different problems

Training creates the model. Inference uses it.

Training
How should the parameters change?

InputLarge datasets and objectives

WorkForward pass, loss, gradients, updates

CostLarge, concentrated, paid up front

ResultA model checkpoint

Inference
What output should this model produce now?

InputA prompt, image, record, or sensor stream

WorkForward passes and optional tool calls

CostSmall per request, repeated at scale

ResultA prediction, response, or action

What “learning” looks like mechanically

Training repeats a simple loop at enormous scale.

01 · FORWARD

Make a prediction

Pass examples through the current model.

ŷ = fθ(x)
02 · COMPARE

Measure error

Use a loss function to score the mismatch.

L(ŷ, y)
03 · BACKWARD

Compute gradients

Estimate how each parameter affected the loss.

θL
04 · UPDATE

Adjust parameters

Take a small step intended to reduce future loss.

θ ← θ − η∇L
The real test is generalization

A model can fit its training world and fail in ours.

TRAINING
DISTRIBUTION
Performance depends on where the model is used.

Populations change. Sensors change. Language changes. Incentives change. People adapt to the model.

Did we test the conditions that matter here?
Neural networks learn representations

Layers transform raw input into features useful for the objective.

The network does not store a human-readable rulebook.

It distributes learned patterns across many parameters and intermediate representations.

Early layers often capture simpler regularities.Later layers combine them into task-relevant structure.Interpretability is possible, but rarely complete.
Now zoom in on one branch

Foundation models are one powerful part of AI, not the whole field.

They combine deep learning, self-supervised pretraining, post-training, retrieval, tools, and product design. Language models are the most visible example.

Deep learningScaleGenerative modelingMultimodalityTools
Language models do not read words the way we do

Text becomes tokens, and tokens become vectors.

Human-centered AI changes the question.
Token IDA discrete entry in a vocabulary
EmbeddingA learned vector for computation
PositionInformation about order
ContextMeaning changes with nearby tokens
The transformer’s central move

Attention lets each token weigh which other tokens matter right now.

The council denied the agent access because it lacked authority.
Attention is a learned routing mechanism.

Each token produces three vectors:

QWhat am I looking for?
KWhat information do I contain?
VWhat information should I pass forward?
Pretraining

Predicting the next token forces the model to learn broad statistical structure.

NEXT
TOKEN
Given the context so far, assign probabilities to possible continuations. Repeat across enormous datasets until the model becomes useful for many tasks.
Post-training

A pretrained model becomes an assistant through additional training and system rules.

Instruction tuning
Learn patterns from demonstrations of desired responses.
Following tasks and formats
Preference learning
Use comparisons, ratings, rewards, or verifiers to favor some outputs.
Helpfulness, style, reasoning behavior
System scaffolding
Add prompts, safety policies, retrieval, tools, monitors, and routing.
Product behavior and authority
Reasoning models

More inference-time computation can improve difficult answers, but it is not free.

None
fastest · cheapest
Low
short deliberation
High
more latency and tokens
Maximum
best effort · highest cost
Spending more compute changes the odds. It does not turn the output into a proof.
Context is not memory

A million-token window can hold more information without making the model remember forever.

Context window

Information included in the current request or conversation.
Long prompts raise cost and can bury relevant evidence.

External memory

Saved records, vector stores, profiles, files, or databases retrieved later.
Storage creates privacy, correction, and retention questions.

Model weights

Statistical patterns learned during training and post-training.
Updating weights requires training, not just another conversation turn.
Retrieval-augmented generation

RAG gives the model evidence at inference time instead of asking its weights to contain everything.

01

Question

The user asks for information or a decision.

02

Search

The system retrieves documents, passages, or records.

03

Select

A ranking step chooses what enters the context.

04

Generate

The model synthesizes an answer from prompt and evidence.

05

Check

Citations, rules, or people verify the result.

Tools change what a language model can do

A model proposes text. A tool can search, calculate, send, buy, or control.

Generate

Draft an answer or plan.

Retrieve

Read current or private information.

Compute

Run code, calculations, or simulations.

Execute

Change another system or the physical world.

An agent is a loop around a model

Agents observe, plan, act, and check until they stop or are stopped.

MODEL
+ RULES
ObservePlanActCheck
The loop creates both usefulness and risk.

Each cycle can gather evidence and correct course. It can also compound a mistaken assumption, repeat a costly action, or continue beyond the user’s intent.

Every agent needs a budget, permission boundary, audit trail, and stop condition.
Multimodal AI

Different media can be translated into representations a shared model can use.

SHARED
REPRESENTATION
SPACE

Text

Tokens, documents, code, structured data

Images + video

Pixels, patches, frames, temporal structure

Audio

Speech, sound events, music, prosody

Action

Tool calls, robot commands, interface events

Efficiency is a technical capability

The best model is often the smallest one that reliably fits the task.

Small and specialized

Less model, tighter task

Fine-tuning and domain data can outperform a larger general model on narrow work.

Mixture of experts

Route tokens through part of the network

Large total capacity without activating every parameter for every token.

Compression

Distill, prune, and quantize

Trade some precision or breadth for lower latency, memory, energy, and cost.

Uncertainty is not one number

A confident output can still come from the wrong model, data, or context.

Output
How ambiguous is this prediction or continuation?
Compare alternatives or calibrate scores.
Model
Does evaluation support use for this task and population?
Respect the competence boundary.
Data
What is missing, stale, selective, noisy, or mismeasured?
Inspect provenance and coverage.
World
Could the environment, behavior, or goal have changed?
Monitor, detect shift, and pause.
Evaluation is a narrowing funnel

A benchmark score is the beginning of evidence, not the end.

General benchmark
Task-specific test
Workflow simulation
Observed outcomes
Evidence becomes more relevant as it becomes more specific.

But specific evaluation is slower, more expensive, and harder to compare across products.

Strong evaluation uses several layers instead of one score.

The frontier is jagged

Impressive performance on one task does not tell you what happens on the next.

≈100%

Coding benchmark

SWE-bench Verified rose from 60% to near 100% in one year.

50.1%

Analog clocks

The top model was only slightly better than chance at reading them.

≈66%

Computer tasks

Agents improved sharply on OSWorld and still failed about one in three attempts.

<20%

Paper replication

Frontier models remained weak on full scientific replication tasks.

State of the art · August 2026

The frontier is moving from chat toward longer, multimodal, tool-using work.

Reasoning
Adjustable effort
Applications trade more inference-time compute for harder tasks.
Context
Million-token windows
Large codebases and document collections can enter one request.
Agents
Longer tool chains
Models increasingly operate browsers, code, and enterprise systems.
Multimodality
Real-time media
Text, vision, audio, video, and action are becoming more integrated.
Efficiency
Smaller and routed models
Cost-performance and specialization compete with raw scale.
A few signals from the current news

Recent releases are competing on agents, speed, multimodality, and cost.

Current
OpenAI GPT-5.6 family
A family spans frontier, balanced, and high-volume tiers, with selectable reasoning effort and a 1.05M-token context window at the top tier.
Jun 30
Claude Sonnet 5
Anthropic emphasizes cost-performance and agentic work, with permanent pricing of $2 input and $10 output per million tokens.
Jul 24
Claude Opus 5
The frontier tier targets long-running agents and professional work at $5 input and $25 output per million tokens.
Aug 13
Gemini 3.7 Flash
Google frames its newest workhorse model around coding and agents, while robotics releases push video understanding into physical action.
There is no single “best model”

Model selection is a trade among quality, speed, cost, and control.

FIT FOR
THIS TASK

Capability

How well does it perform on the work and failure modes that matter?

Operations

Latency, throughput, context, reliability, and integration constraints.

Economics + control

Price, hosting, privacy, adaptability, provider dependency, and governance.

The economy underneath the interface

AI is a supply chain before it is a product.

Energy + land
Electricity, water, grid connections, buildings
local infrastructure
Chips
Fabrication, packaging, accelerators, memory, networking
specialized manufacturing
Cloud
Data centers, clusters, storage, orchestration
capital and scale
Foundation models
Pretraining, post-training, safety, evaluation
data, talent, compute
Applications
Retrieval, tools, workflow, interface, support
distribution and domain access
Work + institutions
Adoption, training, oversight, policy, consequences
legitimacy and trust
Capital is flooding into the stack

Global corporate AI investment more than doubled in 2025.

$581.7B
global corporate AI investment

Up 130% from the prior year, according to the 2026 AI Index.

Global corporate investment$581.7B
Global private investment$344.7B
U.S. private investment$285.9B
China private investment$12.4B
Scale creates concentration

The frontier depends on a small number of firms and physical bottlenecks.

>90%

Industry-built frontier models

Industry produced over 90% of notable frontier models in 2025.

5,427

U.S. data centers

The United States hosts more than ten times as many as any other country.

≈1

Leading chip foundry

TSMC fabricates almost every leading AI chip, according to the AI Index.

Inference has a price curve

Within one model family, the frontier tier can cost 25 times more per token.

OpenAI tier
Typical fit
Input / 1M
Output / 1M
Luna
Cost-sensitive, high-volume work
$0.20
$1.20
Terra
Balance capability and cost
$2.00
$12.00
Sol
Complex professional reasoning
$5.00
$30.00
Short-context standard pricing shown as of August 17, 2026. Long context, tools, priority service, and vendor changes can alter the bill.
A simple unit-economics example

The model choice changes this hypothetical workload from $200 to $5,000 per day.

High-volume tier
$200

10,000 users × 20 turns
2,000 input + 500 output tokens per turn

400M input × $0.20/M + 100M output × $1.20/M
25×
Frontier tier
$5,000

Exactly the same workload and token volume

400M input × $5/M + 100M output × $30/M
Compute becomes an energy-system question

Global data-center electricity use is projected to roughly double by 2030.

≈415TWh · 2024
≈945TWh · 2030
Demand grows about 15% per year in the IEA base case.

Growth is global, but grid congestion, water use, construction, prices, and emissions are experienced locally.

AI can also help optimize energy systems, so the net effect depends on deployment and rebound.

AI changes tasks before it cleanly replaces jobs

Productivity gains are strongest where work is structured and easy to check.

Measured productivity

14–26%

The 2026 AI Index summarizes gains of 14–15% in customer support and 26% in software development studies.

The gains vary with worker experience, task structure, and the ability to verify outputs.

Uneven labor effects

1 in 3

One-third of surveyed organizations expected AI-related workforce reductions in the coming year.

Aggregate job losses remain limited so far, but exposed entry-level hiring pipelines are changing.
Value and burden are distributed differently

A useful AI product can create value for everyone and still divide that value unevenly.

Users

Gain speed, access, convenience, and new capability.
May trade privacy, autonomy, skill, or dependence for that benefit.

Workers

Gain leverage, support, and relief from routine tasks.
May face monitoring, deskilling, work intensification, or reduced entry paths.

Organizations

Gain throughput, consistency, data, and lower marginal cost.
Take on integration, liability, reliability, and governance costs.

Infrastructure owners

Capture rents from scarce chips, cloud capacity, models, and distribution.
Carry capital risk while external costs may fall elsewhere.
A six-question diagnostic
taskdatalearningevidenceactioneconomics

When someone says “AI,” ask what kind of system they actually mean.

Task: What output is the system trying to produce?

Data: What examples and feedback shaped it?

Learning: What architecture, objective, and post-training created the behavior?

Evidence: Where does evaluation support this use?

Action: What can the output influence or execute?

Economics: Who pays, who owns the stack, and who captures value?