Joanna,

The differences between probable-lie and directed-lie CQT polygraphy are explained in Chapter 3 of The Lie Behind the Lie Detector.

The specific directed-lie technique recently adopted by CBP is called the "Test for Espionage, Sabotage, and Corruption" or "TES-C." For documentation and discussion of this technique, see the blog post, "U.S. Customs and Border Protection Polygraph “Test for Espionage, Sabotage, and Corruption” Exposed."

Note that the scoring of probable- and directed-lie polygraph "tests" is similar in that the key to passing is to exhibit stronger reactions to the "control" or "comparison" questions than to the relevant questions.