Comparing Pedagogical Approaches for the Acquisition and Long-Term Robustness of the Control of Variables Strategy By: Michael São Pedro Advisor: Janice Gobert Co-Advisor: Neil Heffernan Sponsors Effectiveness of discovery learning is highly controversial in science education Discovery Learning Open-ended Students ask questions and propose tentative answers Highly unstructured Manipulate objects, perform experiments to confirm their ideas Purported deeper understanding Direct Instruction Clearly established goals Teacher in control of what is learned Highly structured Drill-and-practice of content Better learning gains Probe question Reify Run exp + reify Setup explanation Probe question Setup explanation Construct correct contrast (same as ramp pre/post) Direct + Reify Direct-No Reify Discovery Initial setup Both direct conditions first received initial CVS tutorial. Number of ramp setups controlled in each condition. Pedagogical Approaches Experimental Design Example Questions Overview Showed in Sao Pedro et al. (2009) that two direct instruction variants (with and without reification) significantly outperformed discovery learning on constructing unconfounded experiments starting from an initially multiply confounded experimental setup using a virtual ramp apparatus. Determined robustness of findings by retesting students 6 months after the intervention. We hypothesized direct instruction with reification would show more long-term retention and understanding of CVS than the other conditions. Rationale Inquiry skills can compensate for low science domain knowledge (Hulshof & de Jong, 2006) and may be optimally learned in middle school (Schunn et al. 2007). CVS is a foundational inquiry skill necessary for conducting proper experiments and correctly interpreting data and validating hypotheses. Self-explanation has been found to support deep learning (Chi M. T., 1996) and knowledge integration (Linn & Hsi, 2000). Results Control of Variables Strategy (CVS): a procedure for setting up experimental contrasts such that only one variable is tested and all others are held constant Participants: 57 seventh grade students from a public middle school in central Massachusetts not on IEPs. *Open response items include only those who responded with procedures, not evidential statements. (max = 3) Pre: Pretest Time Direct+ReifyDirect-No ReifyDiscovery Imm: Immediate Posttest Del: Delayed Posttest MeanSDNMeanSDNMeanSDN WPI CVS MultChPre WPI CVS MultChImm WPI CVS MultChDel CVS Explanation*Imm CVS Explanation*Del Strand-Cary ItemsDel Direct Instruction Assessment Direct+Reify and Direct-No Reify students significantly outperformed Discovery on multiply confounded ramp posttest items. Transfer Items No significant differences found between groups on WPI CVS multiple choice, CVS explanations & Strand-Cary transfer items, p> Overall Ramp Performance Collapsing over time, Direct+Reify students construct significantly more unconfounded experiments than both Direct-NoReify and Discovery, p=.014 Though Direct-NoReify has an increase in performance at immediate posttest, there is no significant difference between Direct-NoReify and Discovery when collapsing over time, p>.05 Discovery appears to improve at constructing unconfounded experiments over time. WPI MultCh CVS Ramp Intro Ramp Setups Pretest Immed. Posttest Ramp Setups WPI MultCh CVS CVS Explanation Direct - No Reify Direct + Reify Discovery Interv. Delayed Posttest Ramp Setups WPI + Strand-Cary MultCh CVS CVS Explanation Ramp Re-Intro Last Time….. Now! 2. Singly Confounded Collapsing over time, no significant differences between conditions on mean score, p> Singly Confounded At delayed posttest, mean score was marginally affected by condition, p= Multiply Confounded Collapsing over time, Direct+Reify students made significantly more unconfounded experiments than Discovery (p=.002) and Direct-No reify students (p=.002). 3. Multiply Confounded At the delayed posttest, Direct+Reify made significantly more unconfounded experiments than Direct-No reify (p=.007) and marginally significantly more than Discovery (p=.061) Why teach inquiry? Why the Control of Variables Strategy? Why Reification (Self-Explanation)? US Dept of Ed. R305A NSF-DRL#