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🎾 Builder · 6 missions · First edition

Tennis Data Lab: Practice Companion

Build a fictional practice journal, validate numbers, draw a court strategy, and explain what the data can and cannot tell you.

Browser with pointer or touch input · Ages 9-10, 11-13, 14-16

Open the first mission →Download starter project ↓

A parent or guardian unlocks the missions. Starter projects use fictional data and require no paid AI key.

Course readiness: Authored draft for educator review and pilot teaching. Starter files are original, self-contained classroom adaptations; classroom timing and age fit have not been learner-tested.

Your project

A synthetic tennis practice journal and strategy board

  • Model a small practice record and validate its boundaries.
  • Calculate an aggregate rate with the correct denominator.
  • Translate pointer coordinates into a court direction diagram.
  • Save synthetic journals and review an AI observation against measured facts.

Before you begin

  • Can edit and save a text file with adult support.
  • Can open a local HTML file or a school-hosted copy in a browser.
  • No previous AI account, backend service, or paid API is required.

Materials

  • Computer or tablet with browser; a keyboard and text editor for code changes.
  • Download /lab-starters/tennis-apps/index.html.
  • Paper court, pencil, and two fictional drill cards. No real training session or sports equipment is required.

Your tools

Browser and text editor
Build, inspect, and revise one small app.
An adult downloads /lab-starters/tennis-apps/index.html, saves a working copy named index.html, and opens it in a browser. Reopen or reload after saving edits. If local-file storage is blocked, use an adult-hosted local server; the app itself needs no network.
JR Playground or adult-operated approved assistant
Ask for explanations or compare a suggested revision with observable behavior.
Use only fictional lesson inputs. An adult operates the approved assistant. Every required build has supplied code and works without an AI service.

Your mission sequence

  1. MISSION 1 · 75 MINUTES

    Turn a practice story into data

    Design a small journal that records a goal, an observation, and a reflection for an imaginary player.

    Architect skill: Choose a data model that answers a useful question.

  2. MISSION 2 · 75 MINUTES

    Protect the meaning of the numbers

    Reject impossible counts before a record reaches the journal.

    Architect skill: Enforce invariants at the data boundary.

  3. MISSION 3 · 75 MINUTES

    Use the right denominator

    Calculate a combined target rate from total hits and attempts, then explain its limits.

    Architect skill: Choose an aggregation that matches the question.

  4. MISSION 4 · 75 MINUTES

    Draw an idea on a court

    Turn two taps into a direction arrow and pair the picture with a text description.

    Architect skill: Translate between screen coordinates and model coordinates.

  5. MISSION 5 · 75 MINUTES

    Keep records and review a reflection

    Save synthetic journals and compare a proposed observation with their actual evidence.

    Architect skill: Preserve trustworthy data before asking for interpretation.

  6. MISSION 6 · 75 MINUTES

    Present a trustworthy sports tool

    Demo the journal, rules, aggregate, drawing, and one tested improvement using only fictional players.

    Architect skill: Support each product claim with a demonstration.

Learn online

Six 75-minute sessions: 10 minutes predict/design, 40 minutes build, 15 minutes test with evidence, 10 minutes explain and save. One numbered lesson per session.

Plan around 75 minutes per session; pause and revisit at your own pace.

Adult support: Prepare files and tools, operate any AI service, support reading and debugging, and require the learner to explain and test each adopted change.

Build at camp

Five days with 180 planned minutes per day, including project work and group activities. The course outline does not reserve a camp place.

  1. Day 1: Day 1 — Discover and build

    • Run lesson 1, interview a partner using the fictional scenario, and sketch a clearer screen.
    • Use the remaining lab time for pair programming, movement breaks, and saving a checkpoint.

  2. Day 2: Day 2 — Make rules visible

    • Complete lessons 2 and 3 in two 75-minute blocks.
    • Use 30 minutes for a paper prediction game, break, and comparing actual results.

  3. Day 3: Day 3 — Make it useful

    • Complete lesson 4 and swap devices or roles for a usability test.
    • Spend the remaining time on the lesson camp activity, improvement, and a screen-reader or keyboard check.

  4. Day 4: Day 4 — Connect the pieces

    • Complete lesson 5 with facilitator setup ready before the session.
    • Run a challenge station, peer debugging, and capstone preparation.

  5. Day 5: Day 5 — Test and demonstrate

    • Complete lesson 6 and collect rubric evidence.
    • Use the remaining time for rehearsal, a family-facing demo using fictional data, and individual reflection.
Facilitator preparation
  • The three-hour day includes short movement breaks; do not require uninterrupted screen time.
  • Use driver/navigator pairs and rotate every 15 minutes. Keep an individual prediction and explanation from each learner.
  • Bring a known-working teacher copy and preserve a learner checkpoint before replacing functions. The second camp day contains two complete lesson blocks.

Show what you built

Deliver a browser journal for invented tennis practices with validated records, a correct combined target rate, a directional court diagram and text equivalent, local journal persistence, and a source-reviewed reflection.

Sound data rules
Zero hits and full success accepted; impossible, negative, fractional, and zero-attempt records rejected.
Correct interpretation
4/10 plus 18/20 yields 22/30 and rounded 73%; learner explains the condition caveat.
Useful visual communication
Arrow direction matches two taps at normal and narrow widths and has a matching text description.
Recoverable state
Journal save/load, clear, and invalid-save recovery demonstrated; temporary drawing is accurately labeled.
Evidence-led iteration
Learner shows one tested improvement and a reflection grounded in fictional source records.

Portfolio badge: Sports App Architect

Use the rubric with a guardian or mentor and record your evidence in your builder notebook.

Build with care

  • Use fictional people, tasks, places, and records. Do not import family repositories, private photos, health information, or real junior-player records.
  • Store only classroom sample data. Demonstrate the clear-data control before using a shared computer.
  • Any assistant is adult-operated through JR Playground or an approved classroom setup; keep provider credentials out of browser files.
  • The app describes invented target drills. It does not diagnose health, prescribe training loads, evaluate real children, or guarantee tennis improvement. Physical camp activities are optional paper simulations.

Inspired by our projects

Tennis Tracker
Pre/post-match reflection forms, practice records, aggregate statistics, court-arrow drawing, and AI-supported reflection. This classroom adaptation uses fictional drills and no personal player data.