“…Its usefulness had also been recognized in special education studies (Horner et al, 2005;Marston, 1988), in measuring teaching effectiveness (Lin & Lawrenz, 1999), and self-regulated learning (Schmitz & Wiese, 2006). Time-series is preferred in longitudinal inquiries such as in the assessment of the effectiveness of school reforms (Bloom, 2003;May & Supovitz, 2006), the effect of financial aid to educational quality (Henry & Rubenstein, 2002) and the impact of lotteries to state expenditure for education (Moon, Stanley, & Shin, 2006). Ortega and Iberri-Shea (2005) posit that time-series ''constitutes the single best formal strategy for investigating effects of instruction longitudinally'' (p. 33) in their meta-analysis of approaches used for second-language acquisition.…”