20 questions linked to/from What is wrong with extrapolation?
9 views

### extrapolation from interpolating polynomial [duplicate]

given data points (1,2), (2,4), and (3,6). using lagrange interpolation, I get the polynomial as f(x) = 2x. Now can I use this polynomial to find f (18) [note that 18 lies outside the range of x's of ...
62k views

### What is the meaning of "All models are wrong, but some are useful"

"Essentially, all models are wrong, but some are useful." --- Box, George E. P.; Norman R. Draper (1987). Empirical Model-Building and Response Surfaces, p. 424, Wiley. ISBN 0471810339. What ...
49k views

### Best method for short time-series

I have a question related to modeling short time-series. It is not a question if to model them, but how. What method would you recommend for modeling (very) short time-series (say of length $T \leq 20$...
95k views

### Difference between forecast and prediction?

I was wondering what difference and relation are between forecast and prediction? Especially in time series and regression? For example, am I correct that: In time series, forecasting seems to mean ...
9k views

### Extrapolation v. Interpolation

What is the difference between extrapolation and interpolation, and what is the most precise way of using these terms? For example, I have seen a statement in a paper using interpolation as: "The ...
6k views

### Why law of large numbers does not apply in the case of Apple share price?

Here is the article in NY times called "Apple confronts the law of large numbers". It tries to explain Apple share price rise using law of large numbers. What statistical (or mathematical) errors does ...
12k views

### Why is the mean function in Gaussian Process uninteresting?

I have just started reading about GPs and analogous to the regular Gaussian distribution it is characterized by a mean function and the covariance function or the kernel. I was at a talk and the ...
18k views

### Predicting future values with a regression model

I have a set of predictor variables and a target variable. I am really confused with regards to what method to use for forecasting the target variable. For example, my data set has monthly customer ...
739 views

### How to make predictions with non-parametric regression?

Let's say I have a dataset to which I have estimated a relationship using non-parametric regression, specifically Kernel (obviously in this hypothetical example it's probably overfit slightly). The ...
8k views

### What are the theoretical reasons for why extrapolation "less reliable" than interpolation?

Extrapolation is in general "unreliable". (See "What is wrong with extrapolation?") But it is also commonly said that extrapolation is "less reliable" than interpolation. But why should we ...
7k views

### Difference between non-linear curve fitting and interpolation

I understand the difference between linear curve fitting and interpolation. In interpolation, the targeted function should pass through all given data points whereas in linear curve fitting we find ...
1k views

### Anscombe-like datasets with the same box and whiskers plot (mean/std/median/MAD/min/max)

EDIT: As this question has been inflated, a summary: finding different meaningful and interpretable datasets with the same mixed statistics (mean, median, midrange and their associated dispersions, ...
2k views

### Which gamma regression model to use for extrapolation?

I'm looking for a regression model which would satify these requirements: My target variable follows the exponential distribution, so to my understanding I should use gamma loss function. I have ...