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Week 10 Β· Models and Simulations

Friday

Impact Friday: Models that decide
// Can a simple model predict what will happen next?
⏱ about 20 min

Friday: Impact Friday: Models That Decide

Comet rushes in with a new idea. "Models are great! Let's build one that decides who gets the workbench first."

She shows her rule: members who visited most last week go first. She used the visit counts from the survey.

Wren reads the rule twice. "What do you notice about who is in this data?"

Comet frowns. "Only the 40 members who answered. And M17 visited 23 times, so the volunteer always wins."

"And the 80 members who never answered?" Wren asks.

Nova hovers above the rule. "Would you like a hint?" she asks. "A model can only see what you put into it. Who is invisible here?"

Comet sets down her pencil. "Data analyst, help me check my own rule."

Models that decide things about people

Computing innovations can reflect human biases, through their algorithms or through their data.

Bias can enter at every level of building something. Programmers should act to reduce it.

A model can also carry bias from what was left in or left out.

Comet's workbench rule (a made-up example)What it means
Uses only the 40 survey answersThe 80 members who did not answer are ranked last
Ranks by visits last weekM17, the volunteer with 23 visits, always goes first
Leaves out why people visitA member who needs the bench once a week can never get it
CHECK COMET'S RULE
  • Read the question.
  • Tap your answer.
Comet's rule ranks only members who answered the survey. Where does that bias come from?
Which member would always go first under Comet's rule?
Which change would make workbench time fairer to all 120 members?

Uses nobody planned

Innovations are often used in ways their makers never intended.

Data mining has helped medicine and science. It has also been used to discriminate against groups of people.

Responsible programmers think about unintended uses and their effects. Still, no one can foresee every use.

StatementTrue or false?
Computing innovations can reflect human biases through their data.?
Bias can enter only at the last step of building a model.?
Data mining has been used to discriminate against groups of people.?
A careful programmer can foresee every way a model will be used.?
WHY THIS EXERCISEA model that decides about people needs extra care, because its bias lands on real lives.

Week review

  1. A model predicts from chosen data and features, and its predictions are tested.
  2. Abstraction keeps what matters for the question and hides the rest.
  3. A simulation is a simplified stand-in made for a purpose. Random numbers can stand in for real-world variety.
  4. A hypothesis is tested, and the model is refined when the test disagrees.
  5. Models can carry bias from their data and from what is left out.
ORDER THIS WEEK'S REPAIR BENCH WORK
  • Tap a card.
  • Then tap its spot.
1First
2Next
3Then
4Last
A simplified version of something complex that uses changing values to show how it changes is a ____. Type one word.
WHY THIS EXERCISESimulations let the crew test a bench they do not have yet.
On paper, design a fair workbench sign-up sheet that every member could use, with no names, only time slots and member IDs.

Thoughtful work this week, data analyst. Tomorrow is Mission Quest: model a line at home.

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