Pay sympathy for grand-mas and grand-pas in their 30s, great-grand-parents at 50s, and for a nephew or a niece who is older than her/his uncle or aunt. ;-)

This passage shows a case for Plain ans Simple English:

The primary purpose of this project was to develop a valid, reliable observational measure of father-child interaction, based on research and theory, that predicts child outcomes, identifies fathers' strengths, and will be useful for home visiting practitioners.

I think it says:

The primary purpose of this project was to develop a valid, reliable observational "measure of father-child interaction" that predicts child outcomes, identifies fathers' strengths, and will be useful for home visiting practitioners. This measure of father-child interaction is based on research and theory.

There are grammatical structure and plurality issues if we focused on:

research and theory, that predicts child outcomes, identifies fathers' strengths, and will be useful for home visiting practitioners.

Younger generations really get younger!