Number SensePart I – Basic Numeracy

This video is designed to accompany

Module 1

in

Beyond the NumbersStudent-Centered Activities for Learning

Statistical ReasoningVan-Griner Publishing Company

Inference

in·fer·ence

1. conclusion: a conclusion drawn from evidence or reasoning

2. reasoning process: the process of reasoning from a premise to a conclusion

3. implication: something that is implied

Inferential Reasoning?

Human Inference

An off-hand phrase taken to mean “inferences we make from statistical constructs like charts, graphs, simple summaries.”

Think of it as how you immediately operationalize statistical information. “Reflexive” inferences.

Formal inference is something else and down the road.

H0: same as placebo

HA: better than placebo

Inference in Action

‘Harry Potter and the Deathly Hallows’ sells 8.3 million in first 24 hours … more than 50,000 a minute.

The Associated Press. Published 6:28 PM – 07/22/07

Not Always Easy

Lots of things can compromise seemingly simply inferences.

Obstacles range from very basic to surprisingly subtle.

Goal is to learn to recognize and avoid some of the more common pitfalls.

Decimal Dilemmas

Did Plato inadvertently create the Atlantis myth with a decimal point error?

You see gas advertised for 79 cents a gallon in Great Britain. Do you think that is right?

More Decimal Dilemmas?

Claim has been made that over 4 million women in the U.S. are battered to death each year by a spouse or boyfriend. What do you think?

Several Verizon customers were quoted data rates like “.015 cents per kilobyte. Does that sound right?

Distracting Displays

Parents

Kids

In the New York Times Magazine, Tara Parker-Pope makes the case that teenagers are more conservative than their parents were.

For example, the fraction of high-school seniors who reported that they had recently consumed alcohol fell from 72% in 1980 (illustrated as the big 128 ounce - jug) to 40% in 2011 (illustrated as the little 8-ounce glass).

Seniors 1980

Seniors 2011

Gripping Graphs

As Reported by FOX News

FOX’s Source Graph at AAA

From: Fox Still Struggling With Basic Chart Concepts: Gas Price Edition. February 21, 2012, by SHAUNA THEEL

One-Sentence Reflection

Basic numeracy is a critical step toward the goal of correctly forming human inferences from statistical constructs.