Comprehensive Study Note on Observation Errors and Rater Biases

Definition of Observation Error: An observation error (English terms: observer bias or rater bias) is defined as the deviation of the result of an observation from the actual, true manifestation of a characteristic in the observed object.
Objective of Observation: During an observation, the objective is for the result to reflect the trait manifestation of the observed object as accurately and as unfalsified as possible.
Systematic Observation Errors: A systematic observation error is a specific type of error that falsifies the observation result in a fixed, determined direction. This can manifest in two ways:
- Underestimation: Judging the trait manifestation as lower than it truly is.
- Overestimation: Judging the trait manifestation as higher than it truly is.

Etymology and Nomenclature: Known in English as the "halo-effect," derived from the Greek word $\\ddot{\\alpha}\\lambda\\omega\\varsigma$ (halos), which refers to a (light) halo or ring of light.
Historical Associations: This phenomenon is noted for its inclusion in the works of Allport, Thorndike, and others.
Mechanism: The halo effect is a systematic observation error characterized by the "overshadowing" (radiance) of individual properties onto other properties. This typically occurs when traits that are particularly striking, prominent, or hervorstechend (e.g., attractiveness, politeness, sympathy, or general structure) dominate the observer's perception.
Categories of Influencing Factors:
- The General Impression: A holistic view of the person.
- Specific Structural Features: Distinct physical or personality-based frameworks.
- Attractiveness, Politeness, and Sympathy: Socially desirable traits that often trigger the effect.
Consequences for Impression Formation:
- A positive overall impression consistently results in a more positive evaluation of other, unrelated traits.
- Conversely, secondary properties may be rendered less significant in the final formation of the impression because the primary trait dominates the rater's perspective.

English Terminology: Frequently referred to as the "first impression" or the "primacy effect."
Weighted Information Theory: Research indicates that information gathered about another individual is weighted differently according to the sequence in which it appears.
Chronological dominance: The initial information received (the first information) carries a significantly higher weight in the judgment process than information that follows subsequently.

Tendency to the Center (Tendenz zur Mitte):
- English Term: Error of central tendency.
- Classification: This is considered a systematic observation error or a "response set" during assessments.
- Behavioral Pattern: An observer or individual tends to select middle or neutral answer categories or scale ranges with an unexpectedly high frequency.
- Primary Causes:
  - Uncertainty: A lack of confidence in making a definitive judgment.
  - Low Openness: A resistance to commiting to a specific viewpoint.
  - Lack of Motivation: Minimal effort exerted in the judging process.
  - Lack of Attention: Failure to focus on the nuances of the observed object.
Tendency to Extreme Values (Tendenz zu Extremwerten):
- English Term: Error of tendency to extreme values.
- Classification: Classified as a systematic observation error or response set in evaluations.
- Behavioral Pattern: An observer or rater tends to select the extreme manifestations of a scale (the absolute high or low ends) with an unexpectedly high frequency.

Definition: Observer drift (Beobachterdrift) refers to a change in the evaluation behavior of an observer that occurs due to standards varying over time.
Causes of Temporal Shift: The quality and nature of a judgment may shift during an observation period due to internal state changes in the observer, such as:
- Declining Attention: Reduced focus over longer periods.
- Declining Motivation: A drop in the drive to remain objective or thorough.
Judgment Outcomes: As a result of these temporal changes, the observer may produce judgments that are notably milder or more undifferentiated than those they would have made at the start of the process.