SURVEY DATA FORENSICS
Survey data review in the AI era
Screen unusual response patterns and review data suspected of being simulated or AI-generated. Open Excel/CSV, confirm the items and inspect the findings.
Findings support further review; they do not establish that data were generated by AI.
Files are read and analysed on your device. Survey data is not sent to a server.
Read the main findings first; open detailed tables when you need row-level checks. View assessment criteria and sources
1. Choose data
Up to 5 MB, 5,000 rows in the analysis sheet, 100 columns, 10 sheets and 200,000 workbook cells. Save legacy .xls files as .xlsx; download Google Sheets as Excel first.
Assessment basis
Each indicator has its own criterion. The tool separates statistical calculations, screening rules inherited from the original and contextual information.
References support the concept or formula. A cutoff explicitly identified as tool-specific is not thereby validated by the reference.
Defined calculations with assumptions, such as Mahalanobis distances and Mardia's tests.
Korkmaz, Goksuluk & Zararsiz (2014), The R Journal: MVNReference rules from the original tool; read alongside other indicators, not as conclusive standards.
Kuriakose & Robbins (2016): Don't get dupedFor example timestamps, constant columns and keywords. Check the collection process, questionnaire and codebook.
Ward & Meade (2023): Prevention, identification and recommended best practicesIndicators are not converted into a probability of fabricated data. Exceeding a reference rule calls for further review.
Look up criteria and sources by indicator
Duplicate and near-duplicate responsesStatistic / formula
Criterion applied: Duplicates agree on every selected item. Near duplicates differ on at most one item, among varying profiles; at most 800 rows are compared.
Matching profiles prompt a check of record IDs and data entry. Excess copies differ from all records belonging to duplicate groups.
Assumptions and limitations: A match is a count, not a fraud test. Short questionnaires, few response categories or shared opinions can produce legitimate matches.
Maximum percent match (MPM)Tool-specific rule
Criterion applied: Count profiles with MPM > 85%, both before and after excluding comparison profiles dominated ≥ 70% by one response; at most 600 rows per comparison.
MPM is agreement with the closest profile in the evaluated set. The 85% reference is inherited; the 70% filter is a tool-specific choice.
Assumptions and limitations: Pew shows that one threshold is sensitive to question count, categories, sample size and homogeneity. Exceeding 85% does not establish fabrication or a near-zero chance probability.
Uniform and low-variation response profilesTool-specific rule
Criterion applied: Uniform profile: within-row SD = 0. Low variation: within-row SD ≤ 0.3; only complete valid profiles are used.
Within-row SD describes response variation. The 0.3 cutoff is inherited from the original tool, without calibration for questionnaire length or scale range.
Assumptions and limitations: Do not exclude automatically. Similar wording or consistent opinions can yield low SD; examine reverse-worded items and questionnaire context.
Long strings, IRV and response stylesTool-specific rule
Criterion applied: Same-level run ≥ max(3, floor(k/2)); endpoint/midpoint use > 70% of items; agreement with a two-level alternating pattern ≥ 90%. k is the selected item count.
IRV is within-profile SD; runs depend on item order. These are tool-specific descriptive rules, not universal cutoffs established by the references.
Assumptions and limitations: Endpoints and midpoint use the configured scale; an even scale has no integer midpoint. Items are not automatically reverse-coded.
Blank and out-of-scale cellsStatistic / formula
Criterion applied: Blank cells are separate from unparseable or out-of-range values. Cell percentages use rows × selected items as the denominator.
Separate missingness from coding errors before analysis. Complete-case counts may differ across checks.
Assumptions and limitations: Missing values do not establish low effort, and complete data are not suspicious by themselves. MCAR/MAR/MNAR mechanisms are not inferred and values are not imputed.
Item distributions and entropyStatistic / formula
Criterion applied: Inspect n, mean, SD, skewness, excess kurtosis and frequencies. H = −Σp ln(p), maximum ln(L); H > 0.92 ln(L) is counted by a tool-specific rule.
L is the number of scale categories. Descriptive statistics summarize distribution shape and category use for coding review.
Assumptions and limitations: Uniformity, normality and skewness do not establish response origin. The 92% rule is not a validated fabrication-detection cutoff.
Item and construct-block correlationsStatistic / formula
Criterion applied: Compute Pearson correlations from valid pairs, then summarize their mean, SD and range within and between declared item groups.
Correlations describe shared variation. Name-based groups organize the checks but do not validate a theoretical structure.
Assumptions and limitations: There is no ‘too uniform means fabricated’ threshold. Ordinality, reverse coding, restricted range and pairwise sample sizes affect r; these summaries do not replace CFA.
Cronbach’s alpha by item groupStatistic / formula
Criterion applied: α = k/(k−1) × [1 − ΣVar(item)/Var(total score)], using complete profiles within each group. No authenticity cutoff is applied to alpha.
Alpha summarizes consistency among items intended to measure one construct; item grouping and coding direction matter.
Assumptions and limitations: High alpha does not prove unidimensionality or validity. Similar group alphas do not establish simulation; pooled multi-construct alpha is descriptive only.
First principal component (PCA)Statistic / formula
Criterion applied: PC1 uses each group's correlation matrix; explained variance = λ₁/k. Require at least two varying items and complete n ≥ k + 5.
PC1 describes concentration of variation along one common direction, organized by declared item group.
Assumptions and limitations: No PC1 authenticity cutoff is applied. PCA does not replace EFA/CFA; constants and conceptually unjustified groups limit computation or interpretation.
Mahalanobis multivariate outliersStatistic / formula
Criterion applied: D² = (x−μ)′S⁻¹(x−μ); flag D² > χ² quantile (0.999; k), α = 0.001. Require complete n > k + 5, ≤ 60 items and nonsingular S.
This distance accounts for covariance between items. The chi-square cutoff is an approximate multivariate-outlier reference.
Assumptions and limitations: Continuous/normal assumptions, estimation on the same sample and multiple comparisons limit inference. Outliers or their absence do not verify data origin.
Mardia multivariate normalityStatistic / formula
Criterion applied: Skewness and kurtosis tests use covariance normalized by n, with skewness correction for n < 20. At a 0.05 reading level, p < 0.05 suggests departure from multivariate normality.
Mardia concerns distribution assumptions and estimator choice. Require n > k + 5, ≤ 60 items; at most 600 complete rows are used.
Assumptions and limitations: Likert items are ordinal. p ≥ 0.05 proves neither normality nor authenticity. An evenly spaced subset is not a probability sample of all respondents.
Agreement with the group response profileStatistic / formula
Criterion applied: Correlate each person's profile with the item means of everyone else; require ≥ 3 complete profiles. Negative correlations are counted descriptively.
This leave-one-person-out profile correlation is an implementation of individual/group agreement, not an independent authenticity test.
Assumptions and limitations: It is not an exact reproduction of the original Donlon–Fischer person-fit index. Negative r can reflect genuine opinion differences, reverse coding or nearly equal item means.
Consistency across strongly correlated item pairsTool-specific rule
Criterion applied: Select same-sample pairs with r ≥ 0.6 or r ≤ −0.6; require ≥ 3 pairs in each set to describe within-profile agreement.
The |r| ≥ 0.6 selection is a tool-specific rule for finding empirical item relationships to review against the questionnaire.
Assumptions and limitations: Pairs are not established semantic synonyms/antonyms and may overlap. No validated individual-score cutoff is supplied for automatic exclusion.
Adjacent item-order reversalsTool-specific rule
Criterion applied: Order items by descending mean, omit tied pairs, then count profiles where the later item has a higher response than the preceding adjacent item.
This exploratory Guttman-inspired count reports the actual number of compared adjacent pairs as its denominator.
Assumptions and limitations: It is not a validated polytomous Guttman scale. Interpret only with coherent, aligned items; few reversals do not establish fabrication.
Submission times and intervalsContext review
Criterion applied: Require ≥ 3 valid timestamps; sort them to summarize intervals, CV and clusters of ≥ 3 submissions/minute. No automatic decision cutoff is applied.
Use an explicitly named timestamp column or the first column if > 80% valid dates; only valid Date/clear ISO values are accepted.
Assumptions and limitations: Submission time is not completion duration. Batch entry, classrooms, clock resolution or exports can legitimately produce clustered timestamps.
Keywords and data-source notesContext review
Criterion applied: Search terms such as simulated/synthetic in at most 4,000 cells per selected sheet; report the total hits and up to 25 excerpts.
Sheet, row, column and original excerpts make workbook notes traceable. This is a tool-specific text-search rule.
Assumptions and limitations: Terms can occur in instructions, negations or references. A keyword does not establish the origin of all response records.
Constant non-item columnsContext review
Criterion applied: Count non-item columns with one distinct value among ≥ max(10, floor(50% of rows)) nonblank cells; attention/consent/flag-like names are codebook hints only.
A constant can represent a version code, eligibility condition, screening result or system field.
Assumptions and limitations: All-consenting records can be a legitimate inclusion rule. A name alone does not identify an attention-check item.
Associations between categorical columnsTool-specific rule
Criterion applied: Cramér's V = √[χ²/(n·min(r−1,c−1))]. Small-association description: V < 0.1 and p > 0.05; at most 10 candidate columns, ≥ 30 complete pairs.
Candidates have 2–20 levels outside selected items. p is omitted if minimum expected count < 1 or > 20% of cells have expected counts < 5.
Assumptions and limitations: p > 0.05 does not prove independence; a small association does not prove independent generation. Multiple testing is unadjusted and demographic meaning is not inferred.
Nearly deterministic column mappingsTool-specific rule
Criterion applied: Map each input level to its modal output; report ≥ 98% consistency, ≥ 30 complete records and ≥ 2 levels on each side; at most 14 candidates.
A consistent mapping suggests one field may derive from another. The 98% reference is an original-tool heuristic, not an origin test.
Assumptions and limitations: Derived variables, age grouping, relabelling and legitimate recoding can give high consistency. Check the codebook before treating this as a problem.
Boundary concentrationsTool-specific rule
Criterion applied: For non-items, require ≥ max(50, 50% of rows) numeric values and ≥ 8 levels. Report endpoints with ≥ 5%, ≥ 3×(100/levels), and ≥ 2.5× the adjacent level's share.
These three tool-specific conditions find a jump between an endpoint and its nearest observed level.
Assumptions and limitations: Real measurement bounds, sampling rules, rounding or legitimate clipping can produce pileups. These cutoffs are not a validated falsification test.
