In 2007, the New Zealand Ministry of Education funded a research study  into the effectiveness of Reading Together®. The in-depth study (led by Dr Bryan Tuck) investigated the ongoing implementation (since 2005) of Reading Together® at St Joseph's School Otahuhu, Auckland. The research revealed:
In 2009, a document summarising research evidence relating to Reading Together® (1982-2009) was prepared by The Biddulph Group at the request of Group Māori, Ministry of Education National Office, as part of Whānau Engaged in Learning initiatives within Ka Hikitia. The document is available here.
In 2009, the Ministry of Education's Best Evidence Synthesis School Leadership and Student Outcomes: Identifying What Works and Why  reported that:
Reading Together has proven to be a cost-effective intervention to support parents in assisting their children with reading. [p 162]
Further extracts from the Best Evidence Synthesis follow:
This case explores how one school developed educational connections with its families in a way that had a payoff in terms of impact on student outcomes. ... The case involves the implementation by a senior management team (SMT) of a parent tutoring programme known as Reading Together. Through this programme, schools work with parents to help them develop tutoring skills that have been demonstrated to improve reading comprehension and foster positive parent-child-teacher relationships. The SMT became interested in the programme because it was research-based, the evidence indicated substantially improved outcomes for students, and its demands on resources seemed reasonable in light of the potential gains. [Case 5, pp 236-241]
Note: The Reading Together® programme is also cited in Chapter 7 (pp 162-164) and Chapter 8 (p 188) of the Best Evidence Synthesis.