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Stephen J. Friedman, Outcomes, Learning, and Assessment in General Education 2510. For evolution of resistance to occur in bacteria, which of the followingfactors would be necessary?a. There must be resistant bacteria in the population.b. The bacteria must be exposed to new factors in the environment tocause a change in their cell walls.c. Bacteria species must differ from each other.d. Cell wall structure must be determined by environmental conditions.The items follow a form described by Miller, Linn, and Gronlund (2008)called an interpretative exercise. The idea is to write a passage and test itemsthat students have not seen previously. Of course the content was taught inclass, using different examples. The exercise determines if students havedeveloped the ability to think like scientists—that is, whether they can applywhat they learned previously to a new situation. Writing such passages anditems is labor intensive, but if kept secure they can be used in subsequentsemesters. Selected-response items can be continuously improved usingitem analysis. 20 Indeed, the data from the inaugural administration of theassessment formed the basis for many lively discussions among the facultywho taught the course as they asked themselves: What can be done to improvethe ability of students to think more like scientists? If methods to better teachstudents this skill are subsequently incorporated into the classroom, futureadministrations of the items should confirm their effectiveness. Trends overtime are especially useful within an assessment framework. Unfortunately,many assessment efforts are not sustained.20 Item analysis is best used when answer sheets can be scored by optical scanners. The keyindices are difficulty and discrimination, which are represented as coefficients for each itemand translate into measures of item quality. A full discussion of item analysis can be foundin standard assessment texts like Miller, Linn, and Gronlund (2008).