Chapter 3: Objectives, Outcomes, and Standards for Instruction

Effect Size

In Chapter 3, Section 4, of the textbook we introduce the concept of effect size as a metric by which to determine whether an instructional technique has any supporting data showing evidence of positive impact on student achievement. As is mentioned in the text, Gene V. Glass devised a method called meta-analysis, which actually measures the effect size of teaching techniques. The text goes over how to compute effect size, but the good news is that you don’t have to take the time to compute the effect size for the various teaching techniques because researchers have already done that for you. For chapters 3-10, you will find effect size data for various teaching techniques. Having this information will provide students with a tool that may help them decide which technique is best to use in a given situation. (It will also give them an advantage when reading research that discusses effect size.) Keep in mind that effect size data is not available for every technique, which does not mean that these techniques are ineffective or should not be used. Also, even those techniques with a low effect size may be useful in a limited manner.

In Chapter 3 effect sizes were located for the following concepts:

Teacher Expectancy	0.30 (Bloom, p.6)
Goal Setting for Intended Outcomes	0.40 (Walberg, p. 80)
Behavioral Objectives	0.12 (Walberg, p. 80)
High Expectations	0.32 (Walberg, p. 80)
Goal Setting	1.37, .48, .46, and .55 (Marzano et al., p. 93)

Note: Cohen classified effect sizes (ES) nominally. If an ES were at least 0.2 it is labeled as small, an ES of at least 0.5 is labeled as medium; while an ES of at least 0.8 or greater is labeled as large. An ES under 0.2 is considered as no effect.

No effect	Small	Medium	Large
<0.2	0.2	0.5	0.8 or greater

Note that the primary source for effect size computations is Jacob Cohen (1988), Statistical Power for Behavioral Sciences, 2^nd ed., Hillsdale, NJ: Lawrence Erlbaum Associates. Below are the sources and references for our effect size data.

Bloom, B. S. (1984). "The 2 Sigma Problem: The Search for Methods of Group

Instruction as Effective as One-to-One Tutoring." Educational Researcher,

13, (6), 4-16.

Marzano, R. J., Pickering, D. J., & Pollock, J. E. (2001). Classroom Instruction that

Works: Research-Based Strategies for Increasing Student Achievement.

Alexandria, VA: Association for Supervision and Curriculum Development.

Walberg, H. J. (1999). "Productive Teaching." In New Directions for Teaching

Practice and Research. H. C. Waxman and H. J. Walberg, eds. Berkeley:

CA: McCutchan Publishing Corporation.