Assessment Biases and Scoring Errors

Study Notes

Biases and Scoring Errors

Biases in assessment can compromise fairness and accuracy in evaluating student performance.

Halo Effect

Defined as the influence of a teacher's overall impression of a student on unrelated assessment areas.
Example: A punctual and well-behaved student may receive inflated scores in group work despite limited contributions.

Leniency or Severity Bias

Arises from a teacher's desire to be viewed as compassionate, resulting in higher grades than deserved.
Example: Inflating grades for struggling students to prevent discouragement, despite not meeting standards.

Contrast Effect

Occurs when evaluations rely on comparisons with others rather than assessing individual merit.
Example: A student's essay receives a lower grade when evaluated right after an outstanding essay, overshadowing its merits.

Generosity Error

Characterized by assessors consistently awarding higher marks than warranted.
Example: Assigning full marks for a project to most students to encourage them, regardless of the actual quality or completion.

Rater Drift

Gradual change in an assessor's standards or rubric interpretation over time, affecting scoring consistency.
Example: A teacher starts grading strictly, but becomes lenient as fatigue sets in, leading to variably higher scores.

Severity Error

Describes an assessor being unduly harsh, even on strong student performances.
Example: A well-researched paper receives a low score due to excessive focus on minor grammatical errors instead of the argument's quality.

Biases and Scoring Errors in Assessment of Learning

Halo Effect: Teacher’s overall impression of a student affects grading in unrelated areas; a well-behaved student may receive inflated group work scores.
Leniency or Severity Bias: Assessors may inflate grades due to a desire for compassion; a teacher might raise grades for struggling students despite their work not meeting standards to avoid discouragement.
Contrast Effect: Evaluating a student's performance relative to peers leads to unfair grading; for instance, an essay may be scored lower after an exceptionally good one.
Generosity Error: Accidental over-grading due to compassion; teachers might award full marks to incomplete projects in a bid to boost student morale.
Rater Drift: Assessors’ grading standards may change over time; a teacher may start grading strictly but become lenient as fatigue sets in, impacting consistency.
Severity Error: Overly harsh grading on strong performances; minor grammatical issues might overshadow a well-researched argument in a student’s paper leading to low scores.
Contamination Effect: Irrelevant factors like a student’s classroom behavior influence grading; a disruptive student might receive lower scores on strong presentations due to past behavior.
Similar-to-Me Effect: Assessors may give higher scores to students with whom they share personal similarities; extra credit might be given based on shared hobbies, unrelated to the assessed material.
Teacher Bias: Educators might unintentionally redefine grading criteria over time, leading to inconsistency in assessments across different students or tasks.
Middle-range Bias: Assessors may avoid awarding extreme grades, resulting in most scores clustering in the middle range of the grading scale.