{
  "study": "Pristupnost ceskych firemnich webu",
  "publisher": "CIAD - Cesky institut pro AI a data",
  "url": "https://ciad.cz/studie/pristupnost-ceskych-webu/",
  "license": "CC BY 4.0",
  "generated": "2026-09-11",
  "scan_date": "2026-08-03",
  "note_on_data": "Agregatni data bez domenovych jmen a bez jmen firem. Vzorek je konvenicni (vyzkumny korpus CIAD pouzivany napric paralelnimi bezpecnostnimi a vyzkumnymi studiemi), ne nahodny nebo reprezentativni vzorek ceske ekonomiky.",
  "automated_test_scope_caveat": "An automated accessibility test (axe-core) finds a subset of real accessibility problems - structural and markup-level issues it can verify programmatically. It cannot detect keyboard traps, screen-reader reading-order problems, the descriptive quality of alt text, or whether a form can be completed without a mouse. The headline figure is a floor on the share of sites with accessibility problems, not a complete audit.",
  "methodology_note_vs_archive": "This measurement uses the axe-core WCAG ruleset via a live Playwright run and replaces, rather than refines, an earlier internal CIAD measurement that used the Lighthouse accessibility category and was truncated to 3 recorded checks per site. The two rulesets are comparable in spirit only, not a strict apples-to-apples time series, and no archive figure is published alongside these numbers.",
  "sample": {
    "total_domains_targeted": 282,
    "n_reachable": 224,
    "n_unreachable_or_error": 58,
    "unreachable_error_breakdown": {
      "dns_failure": 34,
      "http_error": 9,
      "timeout": 7,
      "tls_error": 1,
      "script_injection_blocked_by_target_csp_or_trusted_types": 3,
      "navigation_raced_script_injection": 4
    },
    "sampling_method": "convenience sample: CIAD research corpus used across parallel security and research studies, not random or representative of the Czech economy"
  },
  "headline": {
    "denominator_reachable": 224,
    "n_with_at_least_one_violation": 221,
    "n_with_zero_violations": 3,
    "pct_with_at_least_one_violation": 98.7
  },
  "violations_per_site": {
    "denominator": 224,
    "min": 0,
    "median": 4,
    "p75": 6,
    "p90": 8,
    "max": 12,
    "mean": 4.51
  },
  "severity_raw_instance_counts": {
    "note": "Raw count of individual violation instances across all reachable sites, not a per-site or per-check prevalence figure. A single site can contribute multiple instances of the same severity.",
    "critical": 129,
    "serious": 411,
    "moderate": 428,
    "minor": 42,
    "total": 1010
  },
  "per_check_site_prevalence_pct": {
    "note": "Share of the 224 reachable sites on which the given check fired at least once. A site can trigger multiple checks, so the column does not sum to 100%.",
    "denominator": 224,
    "checks": {
      "color-contrast": 68.3,
      "region": 65.2,
      "link-name": 56.7,
      "heading-order": 37.5,
      "landmark-unique": 23.2,
      "image-alt": 22.3,
      "landmark-one-main": 18.8,
      "meta-viewport": 14.3,
      "button-name": 12.5,
      "frame-title": 11.2,
      "page-has-heading-one": 9.8,
      "html-has-lang": 9.8,
      "link-in-text-block": 7.6,
      "label": 6.7,
      "aria-required-children": 6.7,
      "empty-heading": 5.4,
      "landmark-no-duplicate-banner": 5.4,
      "aria-allowed-role": 4.0,
      "image-redundant-alt": 4.0,
      "landmark-no-duplicate-main": 4.5,
      "list": 3.6,
      "document-title": 3.6,
      "landmark-no-duplicate-contentinfo": 3.6,
      "aria-input-field-name": 3.1,
      "landmark-main-is-top-level": 3.1,
      "aria-command-name": 2.7,
      "aria-dialog-name": 3.1,
      "listitem": 3.1,
      "aria-allowed-attr": 3.1,
      "select-name": 2.7
    }
  },
  "axe_ruleset_tags": [
    "wcag2a",
    "wcag2aa",
    "wcag21a",
    "wcag21aa",
    "best-practice"
  ],
  "scan_method": {
    "type": "automated, tool-based, no manual review",
    "engine": "axe-core executed in a Playwright-controlled browser, fresh browser context per site",
    "scope": "single entry URL per domain, one run, page load only, no authentication or interaction",
    "ruleset": "axe-core default tag set: wcag2a, wcag2aa, wcag21a, wcag21aa, best-practice",
    "measurement_window_utc": {
      "min": "2026-08-03T19:18:49.432328+00:00",
      "max": "2026-08-03T19:22:47.442138+00:00"
    }
  }
}