perception of teachers that the scores might be damaging to them professionally (International Reading Association, 1999; Iowa Testing Programs, 2005).

# **_f. Keeping in mind tests sometimes behave differently with certain groups_**

Academic performance tests (or items) do not always measure skills the same way for different groups of students. Different methods for analyzing differential item functioning (DIF) have been in used since the mid 1980s to determine whether a test is being “unfair” to certain populations (see Dorans & Kulick, 1986; Holland & Thayer, 1988; Shealy & Stout, 1993; Swaminathan & Rogers, 1990). DIF occurs when different groups of examinees with the same level of proficiency in a domain have different expected performance on an item; in other words, students with the same ability find it differentially difficult (Mapuranga, Dorans, & Middleton, 2008). Thus, DIF analysis is an important step when evaluating tests for fairness and equity. In DIF analysis the sample is usually divided into two subgroups, but additional subgroups are possible. The reference group provides a baseline for performance (e.g. non indigenous or male) and the focal group is the focus of fairness concerns (e.g. indigenous, black or female). An external reference measure (matching variable) is used to establish score equivalence between the two groups so that difference in performance in a given item can be attributed to DIF and not to other factors. The matching variable can either be an observed or unobserved score and either a univariate or multivariate variable.

Studies have also shown that contextual factors (e.g., language and cultural characteristics) can have an impact on DIF analyses, particularly for non-native speakers. For example, it was found that when Hispanics took the SAT Reasoning Test (formerly the SAT Verbal test), items containing specific linguistic features (e.g., true cognates, false cognates, homographs) and items that are of special cultural interest exhibited DIF. When native language speakers are tested in their native language, DIF occurs on some items between them and non-native speakers due to language familiarity learned outside the classroom: some examinees use the language being tested as an “academic language” while others use the language as a “home language” (Mapuranga, Dorans, & Middleton, 2008). Familiarity of test language goes beyond linguistic references to also include the phrasing and formatting of items (e.g. multiple-choice) and their content, which could be more familiar to certain groups of students than for others. When the item (or test) is administered in different languages, differences in language difficulty and meaning are the most likely explanations (Emenogu & Childs, 2005).

Another possible explanation for differential behavior of items and tests is provided by the concept of stereotype threat, which is the fear –conscious or unconscious– that one's behavior will confirm an existing negative stereotype of a group with which one identifies. This fear has been proven to lead to an impairment of performance in tests both in racial minorities and women. When a fixed biological characteristic such as race or gender is emphasized before a given test, test performance is negatively affected among members of groups for which culturally-shared stereotypes suggest poor performance (Steele & Aronson, 1995).<sup>20</sup> Low performance can also derive from a self-protecting reaction, by which one does not give it the best try in mastering the test because assumes that, no matter what, the stereotype cannot be changed.

> 20 The authors conducted several studies. Studies 1 and 2 varied the stereotype vulnerability of Black participants taking a difficult verbal test by varying whether or not their performance was ostensibly diagnostic of ability, and thus, whether or not they were at risk of fulfilling the racial stereotype about their intellectual ability. Reflecting the pressure of this vulnerability, Blacks underperformed in relation to Whites in the ability-diagnostic condition but not in the nondiagnostic condition (with Scholastic Aptitude Tests controlled). Study 3 validated that abilitydiagnosticity cognitively activated the racial stereotype in these participants and motivated them not to conform to it, or to be judged by it. Study 4 showed that mere salience of the stereotype could impair Blacks' performance even when the test was not ability diagnostic (Steele & Aronson, 1995).

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