Krippendorff's Alpha Calculator
How reliable is coding by two or more coders, allowing missing data?
Spec sheet
krippendorff_alpha · v1.0.0Krippendorff's α via the coincidence matrix
- 01
o_ck = Σ_u (pairs (c,k) in unit u) / (m_u − 1) - 02
α = 1 − (n − 1) · Σ o_ck δ²_ck / Σ n_c n_k δ²_ck - 03
δ²: nominal 0/1 · interval (c − k)² · ratio ((c − k)/(c + k))² · ordinal by rank sums
- Point estimate only; bootstrapped confidence intervals are not computed.
- Ordinal/interval/ratio need numeric codes.
- Krippendorff, K. (2011). Computing Krippendorff's Alpha-Reliability. University of Pennsylvaniastandard
Worked example
computed by the same formulaKrippendorff (2011) reliability example
- Coding matrix — one line per coder, one column per unit
- 1 2 3 3 2 1 4 1 2 . . . 1 2 3 3 2 2 4 1 2 5 . 3 . 3 3 3 2 3 4 2 2 5 1 . 1 2 3 3 2 4 4 1 2 5 1 .
- Level of measurement
- Nominal (categories)
- Krippendorff's α
- 0.743
- Krippendorff's guideline
- Tentative conclusions only (0.667 ≤ α < 0.800)
- Coders
- 4
- Pairable units
- 11
- Pairable values
- 40
Questions
How is the krippendorff's alpha calculated?
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Krippendorff's α via the coincidence matrix. o_ck = Σ_u (pairs (c,k) in unit u) / (m_u − 1) · α = 1 − (n − 1) · Σ o_ck δ²_ck / Σ n_c n_k δ²_ck · δ²: nominal 0/1 · interval (c − k)² · ratio ((c − k)/(c + k))² · ordinal by rank sums
Example: Krippendorff (2011) reliability example?
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Krippendorff's α: 0.743; krippendorff's guideline: Tentative conclusions only (0.667 ≤ α < 0.800).
What does this calculator not cover?
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Point estimate only; bootstrapped confidence intervals are not computed. Ordinal/interval/ratio need numeric codes.
Where do the numbers come from?
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Sources: Krippendorff, K. (2011). Computing Krippendorff's Alpha-Reliability. University of Pennsylvania. The formula is versioned (krippendorff_alpha v1.0.0) and covered by automated tests.
Is my data stored?
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No. The calculation runs in your browser and nothing is sent unless you choose to save a shareable link.
Also searched askrippendorff alpha calculator · intercoder reliability multiple coders · reliability with missing data · content analysis reliability · krippendorff's alpha