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Appendices


Appendix A1 Study characteristics: Resendez & Manley, 2005 (quasi-experimental design)

Characteristic Description
Study citation Resendez, M., & Manley, M. A. (2005). The relationship between using Saxon Elementary and Middle School Math and student performance on Georgia Statewide Assessments. Orlando, Fla. : Harcourt Achieve.
Participants The participants in this study were students in grades 1–8 in 170 intervention schools and 172 comparison schools that were matched on student demographics, geographical location, and baseline math performance on Georgia’s CRCT. This intervention report focuses only on findings for grades 1–5, because grades 6–8 are outside of the scope of this review.1 The authors selected Georgia schools that used the Saxon Elementary School Math curriculum between 2000 and 2005. The sample was obtained from the Georgia Department of Education (GDE). The authors note that per state policy, only school-level data could be released. Data for the intervention group came from 85 schools for first grade, 85 schools for second grade, 83 schools for third grade, 79 schools for fourth grade and 79 schools for fifth grade. Data for the comparison group came from 144 schools for first grade, 144 schools for second grade, 135 schools for third grade, 131 schools for fourth grade, and 129 schools for fifth grade. The number of schools per grade is not mutually exclusive. Some of the schools contained multiple grades so the numbers presented do not represent distinct clusters of schools.
Setting The sample schools were distributed across the state of Georgia and represented a mixture of rural, urban, and suburban communities. The gender and racial compositions of the schools were similar in the intervention schools and comparison schools, with roughly equal gender distribution and more than half of the students white. More than half of the students were educationally disadvantaged, 16% had disabilities, 3% had limited English proficiency, and 6% were gifted in both study conditions.
Intervention The Saxon Elementary School Math curriculum was used as a core curriculum in the intervention schools. The elementary schools in the sample used the version of the Saxon Elementary School Math program that was appropriate for each grade level, and participating schools had used the program for an average of three years (range 1–15 years).
Comparison The schools in the comparison group used a mixture of non-Saxon curricula. More than half of the schools in the comparison group used basal math curricula with chapterbased approaches to teaching math. Five percent of the schools used curricula with an investigative approach. The remaining third of the schools used curricula that were a mix of basal, investigative, computer-based approaches. The authors report no significant differences in baseline math performance between the Saxon and non-Saxon schools.
Primary outcomes and measurement The outcome measure was the Georgia’s Criterion-Referenced Competency Test (CRCT) which assesses competency in number sense and numeration, geometry and measurement, patterns and relations/algebra, statistics and probability, computation and estimation, and problem solving. Fourth-grade students were tested in each school year from 1999–2000 to 2004–05. First-grade, second-grade, third-grade, and fifth-grade students were tested in the spring of school years 2001–02, 2003–04, and 2004–05. All posttest scores are from spring 2005 (see Appendix A2 for more detailed descriptions for outcome measures).
Teacher training No information was provided regarding the teacher training for the intervention.

1 Results from grades 6–8 are being reviewed as part of the WWC Middle School math review.

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Appendix A2 Outcome measures in the math achievement domain

Outcome measure Description
Georgia’s Criterion-Referenced CompetencyTest (CRCT)1 As cited in Resendez & Manley (2005), the CRCT is a criterion-referenced test which is referenced to Georgia’s Quality Core Curriculum Goals. According to the Georgia Department of Education, the CRCT is a multiple-choice test that is valid and reliable for Georgia’s public school students.2 The CRCT math scores range from 150–450, with scores below 300 not meeting standards and scores above 350 exceeding standards. The criteria for meeting the standards vary by objective and grade level. Five objectives are covered by the test: 1) number and number sense, 2) geometry and measurement, 3) patterns, relationships, and algebra, 4) computation and estimation, and 5) problem solving. The cut points are set by the state and take into account the difficulty of the specific objective.

1 The original CRCT scores shown in the report are by objective. Upon request from the WWC, the author calculated the mean overall score across all objectives, controlling for pretest, for each grade.
2 Georgia Department of Education, (n. d.). Criterion-Referenced Competency Tests. Retrieved on September 13, 2006 from http://www.doe.k12.ga.us/curriculum/testing/crct.asp.

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Appendix A3 Summary of subtest findings for math achievement1

  Author's findings from the study  
  Mean outcome (standard deviation2) WWC calculations
Outcome measure Study sample Sample size (schools) Saxon group3 Comparison group3 Mean difference4 (Saxon - comparison) Effect size5 Statistical significance6 (at α= 0.05) Improvement index7
Resendez & Manley 2005 (quasi-experimental design)8
GCRCT: Overall % students meeting objectives Grade 1 229 86.26 (nr) 85.2 (nr) 1.06 na10 ns na10
Average9 for math achievement (Resendez & Manley, 2005): Grade 1 na10 ns na10
GCRCT: Overall % students meeting objectives Grade 2 229 88.31 (nr) 86.86 (nr) 1.45 na10 ns na10
Average9 for math achievement (Resendez & Manley, 2005): Grade 2 na10 ns na10
GCRCT: Overall % students meeting objectives Grade 3 218 86.94 (nr) 85.93 (nr) 1.01 na10 ns na10
Average9 for math achievement (Resendez & Manley, 2005): Grade 3 na10 ns na10
GCRCT: Overall % students meeting objectives Grade 4 210 73.92 (nr) 71.39 (nr) 2.53 na10 ns na10
Average9 for math achievement (Resendez & Manley, 2005): Grade 4 na10 ns na10
GCRCT: Overall % students meeting objectives Grade 5 208 82.46 (nr) 81.66 (nr) 0.80 na10 ns na10
Average9 for math achievement (Resendez & Manley, 2005): Grade 5 na10 ns na10
Domain average9 for math achievement across all grades na10 na na10

ns = not statistically significant
na = not applicable
nr = not reported

1 This appendix reports findings considered for the effectiveness rating and the average improvement indices. Subtest findings from the same studies are not included in these ratings, but are reported in Appendix A4.
2 The standard deviation across all students in each group shows how dispersed the participants’ outcomes are; a smaller standard deviation on a given measure would indicate that participants had more similar outcomes.
3 The intervention group and control group means are pretest-adjusted means provided by the authors and differ from what is in the original study.
4 Positive differences and effect sizes favor the intervention group; negative differences and effect sizes favor the comparison group.
5 The effect sizes were computed based on school-level data, which were likely to be larger than effect sizes based on student-level data. For an explanation on effect size calculation, please see Technical Details of WWC-Conducted Computations.
6 Statistical significance is the probability that the difference between groups is a result of chance rather than a real difference between the groups.
7 The improvement index represents the difference between the percentile rank of the average student in the intervention condition and the percentile rank of the average student in the comparison condition. The improvement index can take on values between -50 and +50, with positive numbers denoting favorable results.
8 The level of statistical significance was reported by the study authors, or where necessary, calculated by the WWC to correct for clustering within classrooms or schools and for multiple comparisons. For an explanation about the clustering correction, see the WWC Tutorial on Mismatch. See the Technical Details of WWC-Conducted Computations for the formulas the WWC used to calculate the statistical significance. In the case of Resendez & Manley (2005), no corrections for clustering or multiple comparisons were needed.
9 This row provides the study average, which in this instance, is also the domain average. The WWC-computed domain average effect size is a simple average rounded to two decimal places. The domain improvement index is calculated from the average effect size.
10 Student-level standard deviations were not available for this study. School-level standard deviations for the intervention group were 6.60 for grade 1, 6.39 for grade 2, 6.50 for grade 3, 8.51 for grade 4, and 6.94 for grade 5. Schoollevel standard deviations for the comparison group were 6.80 for grade 1, 7.35 for grade 2, 7.15 for grade 3, 11.83 for grade 4, and 8.93 for grade 5. Because student-level effect sizes and improvement indices could not be computed, the magnitude of the effect size was not considered for rating purposes. However, the statistical significance for this study is comparable to other studies and is included in the intervention rating. For further details, please see Technical Details of WWC-Conducted Computations.

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Appendix A4 Summary of subtest findings for math achievement1

  Author's findings from the study  
  Mean outcome (standard deviation2) WWC calculations
Outcome measure Study sample Sample size (schools) Saxon group3 Comparison group3 Mean difference4 (Saxon - comparison) Effect size5 Statisticalsignificance6 (at α= 0.05) Improvement index7
Resendez & Manley 2005 (quasi-experimental design)8
GCRCT: Number and number sense Grade 1 229 89.53 (nr) 88.52 (nr) 1.01 na9 ns na9
GCRCT: Geometry and measurement Grade 1 229 90.34 (nr) 90.29 (nr) 0.05 na9 ns na9
GCRCT: Patterns, relations, and Algebra Grade 1 229 87.88 (nr) 86.28 (nr) 1.60 na9 ns na9
GCRCT: Computation and estimation Grade 1 229 78.93 (nr) 77.43 (nr) 1.50 na9 ns na9
GCRCT: Problem solving Grade 1 229 84.64 (nr) 83.49 (nr) 1.15 na9 ns na9
GCRCT: Number and number sense Grade 2 229 88.57 (nr) 86.62 (nr) 1.95 na9 ns na9
GCRCT: Geometry and measurement Grade 2 229 91.46 (nr) 92.36 (nr) -0.90 na9 ns na9
GCRCT: Patterns, relations, and Algebra Grade 2 229 87.05 (nr) 83.58 (nr) 3.47 na9 Statistically significant na9
GCRCT: Computation and estimation Grade 2 229 86.93 (nr) 85.83 (nr) 1.10 na9 ns na9
GCRCT: Problem solving Grade 2 229 87.54 (nr) 85.93 (nr) 1.61 na9 ns na9
GCRCT: Number and number sense Grade 3 218 89.74 (nr) 88.24 (nr) 1.50 na9 ns na9
GCRCT: Geometry and measurement Grade 3 218 93.6 (nr) 92.24 (nr) 1.36 na9 ns na9
GCRCT: Patterns, relations, and Algebra Grade 3 218 86.26 (nr) 85.9 (nr) 0.36 na9 ns na9
GCRCT: Statistics and probability Grade 3 218 87.13 (nr) 85.83 (nr) 1.30 na9 ns na9
GCRCT: Computation and estimation Grade 3 218 86.81 (nr) 85.71 (nr) 1.10 na9 ns na9
GCRCT: Problem solving Grade 3 218 78.11 (nr) 77.64 (nr) 0.47 na9 ns na9
GCRCT: Number and number sense Grade 4 210 71.47 (nr) 70.85 (nr) 0.62 na9 ns na9
GCRCT: Geometry and measurement Grade 4 210 79.22 (nr) 78.16 (nr) 1.06 na9 ns na9
GCRCT: Patterns, relations, and Algebra Grade 4 210 69.76 (nr) 67.7 (nr) 2.06 na9 ns na9
GCRCT: Statistics and probability Grade 4 210 82.15 (nr) 80.17 (nr) 1.98 na9 ns na9
GCRCT: Computation and estimation Grade 4 210 73.12 (nr) 67.65 (nr) 5.47 na9 Statistically significant na9
GCRCT: Problem solving Grade 4 210 67.81 (nr) 63.83 (nr) 3.98 na9 Statistically significant na9
GCRCT: Number and number sense Grade 5 208 79.74 (nr) 77.31 (nr) 2.43 na9 ns na9
GCRCT: Geometry and measurement Grade 5 208 80.77 (nr) 81.54 (nr) -0.77 na9 ns na9
GCRCT: Patterns, relations, and Algebra Grade 5 208 76.16 (nr) 74.56 (nr) 1.60 na9 ns na9
GCRCT: Statistics and probability Grade 5 208 79.82 (nr) 81.52 (nr) -1.70 na9 ns na9
GCRCT: Computation and estimation Grade 5 208 88.74 (nr) 86.62 (nr) 2.12 na9 ns na9
GCRCT: Problem solving Grade 5 208 89.55 (nr) 88.43 (nr) 1.12 na9 ns na9

na = not applicable
nr = not reported
ns = not statistically significant

1 This appendix presents subscale findings for measures that fall in math achievement. Total scale scores were used for rating purposes and are presented in Appendix A3.
2 The standard deviation across all students in each group shows how dispersed the participants' outcomes are; a smaller standard deviation on a given measure would indicate that participants had more similar outcomes.
3 The intervention group and control group means are pretest-adjusted means provided by the authors and differ from what is in the original study.
4 Positive differences and effect sizes favor the intervention group; negative differences and effect sizes favor the comparison group.
5 The effect sizes were computed based on school-level data, which were likely to be larger than effect sizes based on student-level data. The effect sizes may differ from those presented by the authors because the authors calculated Cohen's d using the proportion of variance, while the WWC calculated a Hedges' g using the adjusted means, unadjusted standard deviations, and sample sizes for each group using additional data provided by the authors.
6 Statistical significance is the probability that the difference between groups is a result of chance rather than a real difference between the groups. The WWC used additional data provided by the authors to calculate significance.
7 The improvement index represents the difference between the percentile rank of the average student in the intervention condition and the average student in the comparison condition. The improvement index can take on values between -50 and +50, with positive numbers denoting favorable results.
8 The level of statistical significance was reported by the study authors, or where necessary, calculated by the WWC to correct for clustering within classrooms or schools (corrections for multiple comparisons were not done for findings not included in the overall intervention rating). For an explanation about the clustering correction, see the WWC Tutorial on Mismatch. See Technical Details of WWC-Conducted Computations for the formulas the WWC used to calculate statistical significance. In the case of Resendez & Manley (2005), no corrections for clustering or multiple comparisons were needed.
9 Student-level standard deviations and improvement indices were not available for this study. School-level standard deviations, which were requested by the WWC and provided by the first study author, ranged from 4.50 to 10.32 across grade levels and subtests in the intervention group and from 5.41 to 14.75 across grade levels and subtests in the comparison group. Because student-level standard deviations were not available, student-level effect sizes and improvement indices could not be computed. However, the statistical significance of the findings in Resendez & Manley (2005) is comparable to other studies and is reported in this appendix. For further details, please see Technical Details of WWC-Conducted Computations.

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Appendix A5 Saxon Elementary School Math rating for the math achievement domain

The WWC rates the effects of an intervention in a given outcome domain as: positive, potentially positive, mixed, no discernible effects, potentially negative, or negative.1

For the outcome domain of math achievement, the WWC rated the Saxon Elementary School Math program as having no discernible effects. It did not meet the criteria for other ratings (positive effects, potentially positive effects, mixed effects, potentially negative effects, or negative effects) because the single study that met WWC evidence standards with reservations did not show statistically significant or substantively important effects.

Rating received

No discernible effects: No affirmative evidence of effects.

  • Criterion 1: None of the studies shows a statistically significant or substantively important effect, either positive or negative.

    Met. The one study of Saxon Elementary School Math that met WWC standards with reservations showed an indeterminate effect.

    Other ratings considered

    Positive effects: Strong evidence of a positive effect with no overriding contrary evidence.

    • Criterion 1: Two or more studies showing statistically significant positive effects, at least one of which met WWC evidence standards for a strong design.

      Not met. No studies of Saxon Elementary School Math met WWC evidence standards for a strong design. Further, no studies showed a statistically significant positive effect.

    AND

    • Criterion 2: No studies showing statistically significant or substantively important negative effects.

      Met. No studies showed a statistically significant or substantively important negative effect.

    Potentially positive effects: Evidence of a positive effect with no overriding contrary evidence.

    • Criterion 1: At least one study showing a statistically significant or substantively important positive effect.

      Not met. No studies showed a statistically significant or substantively important positive effect.

    AND

    • Criterion 2: No studies showing a statistically significant or substantively important negative effect and fewer or the same number of studies showing indeterminate effects than showing statistically significant or substantively important positive effects.

      Not met. No studies showed a statistically significant important effect, either negative or positive. The one study of Saxon Elementary School Math that met WWC evidence standards with reservations showed an indeterminate effect.

    Mixed effects: Evidence of inconsistent effects as demonstrated through either of the following criteria.

    • Criterion 1: At least one study showing a statistically significant or substantively important positive effect, and at least one study showing a statistically significant or substantively important negative effect, but no more such studies than the number showing a statistically significant or substantively important positive effect.

      Not met. No studies of Saxon Elementary School Math showed a statistically significant or substantively important effect, either positive or negative.

    OR

    • Criterion 2: At least one study showing a statistically significant or substantively important effect, and more studies showing an indeterminate effect than showing a statistically significant or substantively important effect.

      Not met. No studies of Saxon Elementary School Math showed a statistically significant or substantively important effect.

    Potential negative effects: Evidence of a negative effect with no overriding contrary evidence.

    • Criterion 1: At least one study showing a statistically significant or substantively important negative effect.

      Not met. No studies of Saxon Elementary School Math showed a statistically significant or substantively important negative effect.

    AND

    • Criterion 2: No studies showing a statistically significant or substantively important positive effect, or more studies showing statistically significant or substantively important negative effects than showing statistically significant or substantively important positive effects.

      Met. No studies of Saxon Elementary School Math showed a statistically significant or substantively important positive effect.

    Negative effects: Strong evidence of a negative effect with no overriding contrary evidence.

    • Criterion 1: Two or more studies showing statistically significant negative effects, at least one of which met WWC evidence standards for a strong design.

      Not met. No studies showed a statistically significant negative effect or met WWC evidence standards for a strong design.

    AND

    • Criterion 2: No studies showing statistically significant or substantively important positive effects.

      Met. No studies of Saxon Elementary School Math showed a statistically significant or substantively important positive effect.

    1 For rating purposes, the WWC considers the statistical significance of individual outcomes and the domain level effect. The WWC also considers the size of the domain level effect for ratings of potentially positive or potentially negative effects. See the WWC Intervention Rating Scheme for a complete description.

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    Appendix A6 Extent of evidence by domain

      Sample size
    Outcome domain Number of studies Schools Students Extent of evidence1
    Math achievement 1 299 nr Small

    nr = not reported

    1 A rating of "medium to large" requires at least two studies and two schools across studies in one domain, and a total sample size across studies of at least 350 students or 14 classrooms. Otherwise, the rating is "small."

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