Purposes:
Uses:
This is a good introductory activity to use in Chapters 1 or 3 to illustrate the ideas of "sampling," "validity" (bias and distortion), "target-method match," and alignment between assessment and instruction.
Rationale:
Participants may have heard rhetoric that suggests that one form of assessment is better than another in all circumstances and for all purposes, and that a single assessment should yield all the information needed. Actually, no single type of assessment can yield all the information needed for all users and uses. And, different types of assessment methods are better suited to gather information about different types of student achievement targets (see Chapter 1, Key 3—Target-Method Match) or for different purposes (see Key 2—Clear and Appropriate Purposes). In this activity, participants will gain perspective on the strengths and weaknesses of various types of assessments.
Materials:
Time Required:
40-60 minutes
Facilitators Notes:
Ask participants to note the reasons for their choices.
Indicate participant responses on the Overhead A1.8,O2—Sam's Story Summary Chart by drawing a line though the category(ies) that represent the majority of responses.
Look at the measures that were rated the best. What do these have in common? (Possible answers: they're all closely related to the target that we were making a decision about; they include multiple samples of work; they are "authentic.")
Look at the measures that were rated the lowest. Why did they get such low ratings? (Possible answers: they may be biased, marginally relevant to the decision at hand, not "authentic" enough, or not comprehensive enough.)
Tie to the concept of sampling (Chapter 1, Key 4—Bias and Distortion): When we try to determine Sam's performance in math, it's obviously impractical to see how well he can solve every possible problem there is. Nonetheless, you as a teacher want to get an accurate idea of how well Sam can handle the full array of possible tasks that Sam might be expected to encounter. That full array of possible tasks is called a "domain of knowledge."
Since it's impossible to see how well Sam can perform on the entire range of math problems, we have to select a "sample" of math problems from the entire assessment domain. We try to sample the contents of a domain in a representative fashion so that, based on how well students do on the sample, we can make inferences about the students' status with respect to the entire domain.
Ask participants which items on the list "sample" best. (Answers: in-class math tests, portfolio.)
Tie to the concept of validity (Chapter 1, Key 4—Eliminating Sources of Bias and Distortion): Validity has to do with the extent to which we can make good decisions such as:
Ask participants which items on the list they feel are the most valid for the purpose of making a mastery decision? Why?
Tie to the concept of matching method to purpose (Chapter 2, Key 2—Clear and Appropriate Purposes): Note that the reason the teacher wanted information about Sam was to "decide about Sam's mastery of the content and to design an instructional plan." Ask teachers if one's decisions about which evidence to trust would be different if the purpose were different, for example, to decide if Sam were working up to potential? In that case, what measures might be best?