*When I use a word *Humpty Dumpty said in a rather scornful tone, *it means just what I choose to mean - neither more nor less*.

*The question is*, said Alice*, whether you can make words mean so many different things*.

*The question is* said Humpty Dumpty* which is to be the master*.

*Through the Looking Glass*, Chapter 6

The mantra of #NoEstimates is that No Estimates is not about Not Estimating. Along with that oxymoron comes

**Forecasting is Not Estimating**

- Forecasting the future based on past performance is not the same as estimating the future from past performance.
- The Humpty Dumpty logic is
**Forecasting ≠ Estimating.**

This, of course, redefines the standard definition of both terms. Estimating is a rough calculation or judgment of a value, number, quantity, or extent of some outcome.

An estimate is Approximation, prediction, or projection of a quantity based on experience and/or information available at the time, with the recognition that other pertinent facts are unclear or unknown.

- Let’s estimate how many Great Horned Owls are in the county by sampling.
- Let’s estimate the total cost of this project using reference classes assigned to work element duration and running a Monte Carlo simulation

Forecasting is a prediction of a future event

- Let’s produce weather forecast for the next five days

Both Estimating and Forecasting result in a probabilistic output in the presence of uncertainty

**Slicing is Not Estimating??**

Slicing work into smaller pieces so that "standard" size can be used to project the work effort and completion time. This is a standard *basis of estimate* in many domains. So slicing is Not Estimating in the #NoEstimates paradigm. In fact slicing is Estimating, another inversion of the term

No means Yes

**Past ****Performance is**** #NoEstimates**

using Past Performance to estimate future performance is core to all estimating processes. Time series used to estimate possible future outcomes is easily done with ARIMA, 4 lines of R, and some raw data as shown in *The Flaw of Averages*. But as described there, care is needed to confirm the future is like the past.

**When We Redefine Words to Suite Our Needs We're Humpty Dumpty**

Lewis Carol's *Alice in Wonderland* is political allegory of 19th century England. When #NoEstimates redefines established mathematical terms like *Forecasting* and *Estimating* and ignores the underlying mathematics for time series forecasting, ARIMA for example, they are willfully ignoring established practices and replacing them with their own untested conjectures.

The key here *ways to make decisions with NO ESTIMATES*. OK, show how that is not actually an estimating technical, no matter how simple or flawed and estimating technical.