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bias

/ˈbaɪəs/·noun

a built-in tilt that skews judgments, readings, or results toward one side
Fig. 1 — Two weights go onto the balance, and they are identical — same size, same stamp, one and one.
01Definition

Bias is a built-in tilt — a tendency that pushes judgments, readings, or results consistently to one side before the judging even starts. The word began oblique in the literal sense: French biais, a slant, the diagonal of cloth, the weighted side of a wooden bowl in the old game of bowls. A bias can be conscious or invisible, human or mechanical; a survey, an algorithm, or a referee can each carry one. It need not mean lying: a loaded scale reports honestly what it feels — the tilt was installed earlier, in what it was built to feel.

02In use
  • iEven a small sampling bias can distort the results of an otherwise careful study.
  • iiThe shortlist was arbitrary to begin with, and the panel's bias toward insiders did the rest.
  • iiiNew hires complete training on unconscious bias before joining their first interview panel.
03Collocations
  • bias toward
  • bias against
  • unconscious bias
  • introduce bias
  • confirmation bias
  • media bias

Family biased (adjective) · unbiased (adjective) · biases (plural noun)

04Relations

=prejudice, partiality, slant, predisposition, skew

≠impartiality, objectivity

06TOEFL & IELTS

A core word of TOEFL psychology and media passages (confirmation bias, unconscious bias, media bias) and of data discussions in both exams. The grammar trap outranks the meaning: bias is the noun, biased the adjective — 'I am biased', never 'I am bias' — and the prepositions split by direction: biased toward what is favoured, biased against what is not. Two syllables, BY-us. When claiming bias in an essay, hedge like a researcher: 'the sample may introduce bias', 'studies suggest'.

07Asked
Is it 'I am bias' or 'I am biased'?
Always 'I am biased'. Bias is the noun (a thing you have), biased the adjective (a thing you are): 'I have a bias toward mornings' or 'I am biased toward mornings', never 'I am bias' — that error reads like 'I am opinion'. The -ed form keeps a single s, biased, and the verb runs bias, biases, biased, biasing.
Is it 'biased towards' or 'biased against'?
Both, pointing opposite ways. Biased toward(s) — or in favour of — means unfairly inclined FOR something: reviewers biased toward familiar names. Biased against means unfairly set AGAINST it: a test biased against non-native speakers. The noun takes the same pair ('a bias toward risk', 'a bias against change'), so learning the two prepositions covers the whole family.
What is the difference between bias and prejudice?
Bias is the wider word: any consistent tilt, mild or strong, positive or negative, human or statistical — a scale can have a bias, as the loaded balance in the scene above does. Prejudice is narrower and darker: a pre-formed judgment about people based on group membership, negative and emotionally held. All prejudice is bias; most bias is not prejudice.
What is bias in AI and machine learning?
Systematic error that makes a model's outputs unfairly favour or disfavour certain groups or answers — usually inherited from skewed training data or design choices, since a system trained on tilted examples learns the tilt as if it were truth. Studies suggest such models can even amplify the patterns they absorb. Engineers also use bias as a neutral technical term inside the math, a separate sense worth knowing exists.
What is confirmation bias?
The tendency to notice, favour, and remember evidence that supports what you already believe, while contrary evidence slides past — a term introduced by psychologist Peter Wason in the 1960s. It is the flagship example of a cognitive bias and a fixture of TOEFL psychology passages. The unsettling part is its invisibility from inside: the cherry-picking feels exactly like fair reading.
What is the plural of bias, and how is it pronounced?
Biases — 'the study controlled for several biases'. The word itself is two syllables, BY-us (/ˈbaɪəs/), not 'bice'. Verb forms standardly keep the single s (biased, biasing), though British English admits biassed as a variant. If you can run 'focus, focuses, focused, focusing', the whole pattern transfers directly.
What does 'cut on the bias' mean in sewing?
Cut diagonally, at 45 degrees to the fabric's weave — the bias is that slanting grain, and cloth cut along it stretches and drapes in ways a straight cut cannot. This is the word's original, literal sense: the oblique line. The judgment meaning grew out of it — a mind running on the bias is angled off the straight grain — which makes the sewing room the word's etymology in action.