Practice Flashcards
Flip to reveal answersName the five model types in IB AI SL and their general forms.
Track your progress — Sign up free to save your progress and get smart review reminders based on spaced repetition.
All 16 Flashcards — Choosing the right model type
Sign up free to track progress and get spaced-repetition review schedules.
Question
Name the five model types in IB AI SL and their general forms.
Answer
Linear: y = mx + c. Quadratic: y = ax² + bx + c. Exponential: y = a · bˣ. Power: y = axⁿ. Sinusoidal: y = a sin(bx + c) + d.
Question
Which model type is best for a quantity that grows proportionally to itself (e.g. bacteria doubling)?
Answer
Exponential — constant percentage growth = constant ratio between successive values = exponential model.
Question
Which model type produces a repeating (periodic) graph?
Answer
Sinusoidal (trigonometric). Tides, temperature cycles, sound waves — any periodic real-world quantity.
Question
A scatter plot shows a clear straight-line pattern. Which model should you choose?
Answer
Linear. A straight-line scatter plot is the defining sign of a linear model.
Question
Scatter plot curves upward and passes near the origin. Which two models should you consider?
Answer
Power (y = axⁿ) or exponential (y = a · bˣ). The near-origin hint favours power. Compare R² after fitting both.
Question
Scatter plot rises symmetrically then falls, forming a single peak. Which model fits?
Answer
Quadratic — single turning point, symmetric parabola shape.
Question
Scatter plot oscillates up and down repeatedly at regular intervals. Which model fits?
Answer
Sinusoidal — regular repeating pattern = periodic = trigonometric model.
Question
IB says "Suggest a suitable model and give a reason." How do you get full marks?
Answer
Name the model type AND give one clear reason based on the shape or context. E.g. "Exponential, because the data shows a constant ratio between successive values."
Question
Both power and exponential curves go upward. How do you tell them apart?
Answer
Power (y = axⁿ): may pass through origin, no horizontal asymptote to the right. Exponential (y = a · bˣ): never passes through origin, has horizontal asymptote y = 0 as x → −∞.
Question
Data: (1, 3), (2, 12), (3, 48). Check if the ratio between successive y-values is constant.
Answer
12/3 = 4 and 48/12 = 4. Constant ratio → exponential model.
Question
Power regression R² = 0.91; exponential regression R² = 0.98. Which do you choose?
Answer
Exponential — higher R² means it explains more of the variation. Choose the model with the higher R².
Question
IB asks "Explain why exponential is more appropriate than linear." How do you answer?
Answer
State that the data shows a constant multiplicative (percentage) growth rate, not a constant additive change — which matches exponential, not linear.
Question
Population doubles every 5 years. Which model is most appropriate?
Answer
Exponential — doubling at a constant time interval means a constant ratio between values, which is the defining feature of exponential models.
Question
A ball follows a single arc up and down. Which model?
Answer
Quadratic — the path is a parabola. It has one turning point and is not periodic (doesn't repeat).
Question
Electricity use follows the same pattern every 24 hours. Which model?
Answer
Sinusoidal — regular repeating cycle with constant period.
Question
Drag force is proportional to the square of speed. Which model?
Answer
Power model: F = av², where n = 2.
Read the notes
Full study notes for Choosing the right model type
Topic 2.6 hub
Modeling skills
More from Topic 2.6
All flashcards in this topic
Math AI SL exam skills
Paper structures & tips
Track your progress with spaced repetition
Sign up free — Aimnova tells you exactly which cards to review and when, so you remember everything before your IB exam.
Start Free