Date of Award:


Document Type:


Degree Name:

Doctor of Philosophy (PhD)


Human Development and Family Studies

Committee Chair(s)

Kay Bradford


Kay Bradford


Joshua Novak


David Schramm


Travis Dorsch


Michael Twohig


The purpose of this study was to explore the trajectories of relationship quality for a sample of 777 adult participants attending the Smart Steps: Embrace the Journey stepfamily relationship education course. Rather than assume that all program participants had similar relationship quality trajectories by averaging their scores together in a growth curve analysis, growth mixture modeling was used to allow for a variety of sub-groups (classes), each with a unique trajectory. A prevention science approach was then taken to address possible predictors of each trajectory class in order to identify the risk and protective factors that influence participants’ trajectories.

It was found that two relationship quality trajectory classes were present in the data for men; a “high and rising group” and a “mid and rising group.” The two groups had similar increases in relationship quality over time but began at two different levels. The analysis on the women’s data showed three groups: a “high and rising” and a “mid and rising” group similar to those found within the men’s data, and a “low and falling” group who began at a rather low relationship quality level and reported declining levels over time.

Only a few variables emerged as risk and protective factors predicting trajectory class membership, and the results were consistent for both men and women. Members of the high and rising class were more likely to report higher levels of commitment and agreement on parenting than those in the mid and rising class. For the women, members in the low and falling class were more likely to report low levels of commitment and parenting agreement. Class membership was not predicted by a number of demographic variables signifying that the course is effective within a wide range of participants. These findings support previous research on the effectiveness of stepfamily relationship education in promoting relationship quality within a wide array of stepfamily participants.