motivation

You work faster as the finish line appears.

A 2006 study by Kivetz, Urminsky, and Zheng provided empirical evidence supporting the goal gradient effect in consumer loyalty programs.

The goal gradient effect itself was originally proposed by Clark Hull in 1932.

You are more likely to finish a project when you break it into smaller, measurable segments.

Where this comes from

Study: Kivetz, Urminsky, and Zheng, 2006
What the check found: The study provided modern evidence for the effect, but attributing the discovery of the 'goal gradient effect' to a 2006 paper is historically inaccurate.
Confidence: Solid, with limits

One of these every day, and every one names the study it came from. When a finding is contested, it says so.