{"id":83,"date":"2005-09-11T03:39:20","date_gmt":"2005-09-11T03:39:20","guid":{"rendered":"http:\/\/alephnaught.wordpress.com\/2005\/09\/11\/human-error\/"},"modified":"2008-10-31T16:33:40","modified_gmt":"2008-10-31T23:33:40","slug":"human-error","status":"publish","type":"post","link":"https:\/\/www.alephnaught.com\/Blog\/2005\/09\/11\/human-error\/","title":{"rendered":"Human Error"},"content":{"rendered":"<div id=\"content_div-83\">\n<div><span style=\"font-family: Helvetica;\"><strong>Title<\/strong>: <a href=\"http:\/\/www.amazon.com\/exec\/obidos\/tg\/detail\/-\/0521314194\/qid=1126437139\/sr=2-1\/ref=pd_bbs_b_2_1\/102-9495726-4240950?v=glance&amp;s=books\" target=\"NewWindow\">Human Error<\/a><\/span><br \/>\n<span style=\"font-family: Helvetica;\"><strong>Author<\/strong><\/span><span style=\"font-family: Helvetica;\">: James Reason<\/span><br \/>\n<span style=\"font-family: Helvetica;\"><strong>Paperback<\/strong><\/span><span style=\"font-family: Helvetica;\">: 316 pages<\/span><br \/>\n<span style=\"font-family: Helvetica;\"><strong>Publisher<\/strong><\/span><span style=\"font-family: Helvetica;\">: Cambridge University Press (October 26, 1990)<\/span><br \/>\n<span style=\"font-family: Helvetica;\"><strong>Language<\/strong><\/span><span style=\"font-family: Helvetica;\">: English<\/span><br \/>\n<span style=\"font-family: Helvetica;\"><strong>ISBN<\/strong><\/span><span style=\"font-family: Helvetica;\">: 052131419<\/span><\/div>\n<div>\n<h3>Overview<\/h3>\n<p>This book is very academic, but does have useful information about the reasons people make mistakes and how to categorize them.  This kind of information is crucial for understanding how to make software more survivable &#8220;in the wild.&#8221; To understand the following tables and diagrams, you need to understand a little about GEMS, the Generic Error-Modeling System.  Reason separates errors into three categories:<\/p>\n<ul>\n<li>Skill-Based Errors (SB)<\/li>\n<li>Rule-Based Errors (RB)<\/li>\n<li>Knowledge-Based Errors (KB)<\/li>\n<\/ul>\n<h3>Distinctions between error types<sup><a href=\"#note2\">2<\/a><\/sup><\/h3>\n<table border=\"1\">\n<tbody>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>DIMENSION<\/span><\/span><\/strong><\/td>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>SKILL-BASED (SB) ERRORS<\/span><\/span><\/strong><\/td>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>RULE-BASED (RB) ERRORS<\/span><\/span><\/strong><\/td>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>KNOWLEDGE-BASED (KB) ERRORS<\/span><\/span><\/strong><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>TYPE OF ACTIVITY<\/span><\/span><\/strong><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Routine actions<\/span><\/span><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Problem-solving<br \/>\nactivities<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>FOCUS OF ATTENTION<\/span><\/span><\/strong><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>On something other than the<br \/>\ntask in hand<\/span><\/span><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Directed<br \/>\nat problem-related issues<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>CONTROL MODE<\/span><\/span><\/strong><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Mainly<br \/>\nby automatic processors<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Limited, conscious processes<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>PREDICTABILITY OF ERROR<br \/>\nTYPES<\/span><\/span><\/strong><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Largely<br \/>\npredictable &#8220;strong-but-wrong&#8221; errors<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Variable<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>RATIO OF ERROR TO OPPORTUNITY<br \/>\nFOR ERROR<\/span><\/span><\/strong><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Though<br \/>\nabsolute numbers may be high, these constitute a small proportion of the<br \/>\ntotal number of opportunities for error<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Absolute numbers small, but<br \/>\nopportunity ratio high<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>INFLUENCE OF SITUATIONAL<br \/>\nFACTORS<\/span><\/span><\/strong><\/td>\n<td colspan=\"2\" align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Low<br \/>\nto moderate; intrinsic factors (frequency of prior use) likely to exert<br \/>\nthe dominant influence<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Extrinsic factors likely<br \/>\nto dominate<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>EASE OF DETECTION<\/span><\/span><\/strong><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Detection usually fairly<br \/>\nrapid and effective<\/span><\/span><\/td>\n<td colspan=\"2\"><span style=\"font-family: Arial,Helvetica;\"><span>Difficult,<br \/>\nand often only achieved through external intervention<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>RELATIONSHIP TO CHANGE<\/span><\/span><\/strong><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Knowledge of change not assessed<br \/>\nat proper time<\/span><\/span><\/td>\n<td align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>When<br \/>\nand how anticipated change will occur unknown<\/span><\/span><\/td>\n<td align=\"center\" valign=\"CENTER\"><span style=\"font-family: Arial,Helvetica;\"><span>Changes<br \/>\nnot prepared for or anticipated<\/span><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3>The dynamics of the generic error-modeling system (GEMS)<sup>3<\/sup><\/h3>\n<p><span style=\"font-family: Helvetica;\"><br \/>\n<\/span><a href=\"https:\/\/i0.wp.com\/www.alephnaught.com\/Blog\/wp-content\/uploads\/2008\/05\/dynamics1.jpg\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" data-attachment-id=\"327\" data-permalink=\"https:\/\/www.alephnaught.com\/Blog\/2008\/05\/12\/the-getty-villa\/innerperistylelength\/\" data-orig-file=\"https:\/\/i0.wp.com\/www.alephnaught.com\/Blog\/wp-content\/uploads\/2008\/05\/innerperistylelength.jpg?fit=375%2C500&amp;ssl=1\" data-orig-size=\"375,500\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;}\" data-image-title=\"innerperistylelength\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/www.alephnaught.com\/Blog\/wp-content\/uploads\/2008\/05\/innerperistylelength.jpg?fit=375%2C500&amp;ssl=1\" class=\"aligncenter size-full wp-image-327 colorbox-83\" src=\"https:\/\/i0.wp.com\/www.alephnaught.com\/Blog\/wp-content\/uploads\/2008\/05\/dynamics1.jpg?resize=450%2C505\" alt=\"\" width=\"450\" height=\"505\" \/><\/a><\/p>\n<h3>Failure modes at each performance level<sup><a href=\"#note4\">4<\/a><\/sup><\/h3>\n<h3><strong><span style=\"font-family: Verdana,Arial,Helvetica,sans-serif; font-size: x-small;\">Skill-Based (SB) Performance<\/span><\/strong><\/h3>\n<table border=\"1\">\n<tbody>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>Inattention<\/span><\/span><\/strong><\/td>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>Overattention<\/span><\/span><\/strong><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Double-capture slips<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Omissions<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Omissions following interruptions<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Repetitions<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Reduced intentionality<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Reversals<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Perceptual confusions<\/span><\/span><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Interference errors<\/span><\/span><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong><span style=\"font-family: Verdana,Arial,Helvetica,sans-serif; font-size: x-small;\">Rule-Based (RB) Performance<\/span><\/strong><\/p>\n<table border=\"1\">\n<tbody>\n<tr>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>Misapplication<br \/>\nof good rules<\/span><\/span><\/strong><\/td>\n<td><strong><span style=\"font-family: Arial,Helvetica;\"><span>Application of bad rules<\/span><\/span><\/strong><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>First exceptions<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Encoding deficiencies<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Countersigns and nonsigns<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Action deficiencies<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Informational overload<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Wrong rules<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Rule strength<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Inelegant rules<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>General rules<\/span><\/span><\/td>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Inadvisable rules<\/span><\/span><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Redundancy<\/span><\/span><\/td>\n<td><\/td>\n<\/tr>\n<tr>\n<td><span style=\"font-family: Arial,Helvetica;\"><span>Rigidity<\/span><\/span><\/td>\n<td><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><strong><span style=\"font-family: Verdana,Arial,Helvetica,sans-serif; font-size: x-small;\">Knowledge-Based (KB) Performance<\/span><\/strong><\/p>\n<table border=\"1\">\n<tbody>\n<tr align=\"left\" valign=\"top\">\n<td>Selectivity<\/td>\n<\/tr>\n<tr>\n<td>Workspace limitations<\/td>\n<\/tr>\n<tr>\n<td>Out of sight out of mind<\/td>\n<\/tr>\n<tr>\n<td>Confirmation bias<\/td>\n<\/tr>\n<tr>\n<td>Overconfidence<\/td>\n<\/tr>\n<tr>\n<td>Biased reviewing<\/td>\n<\/tr>\n<tr>\n<td>Illusory correlation<\/td>\n<\/tr>\n<tr>\n<td>Halo effects<\/td>\n<\/tr>\n<tr>\n<td>Problems with causality<\/td>\n<\/tr>\n<tr>\n<td>Problems with complexity<\/td>\n<\/tr>\n<tr align=\"left\" valign=\"top\">\n<td>Problems with delayed feed-back<\/td>\n<\/tr>\n<tr>\n<td>Insufficient consideration of processes in time<\/td>\n<\/tr>\n<tr>\n<td>Difficulties with exponential developments<\/td>\n<\/tr>\n<tr>\n<td>Thinking in causal series not causal nets<\/td>\n<\/tr>\n<tr>\n<td>Thematic vagabonding<\/td>\n<\/tr>\n<tr>\n<td>Encysting<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><a name=\"failuremodes\"><\/a><span style=\"font-family: helvetica;\">Footnotes<\/span><\/h3>\n<p><a name=\"note1\"><\/a><sup>1<\/sup> All footnotes and quotations that are not otherwise attributed are from:<\/p>\n<p><span style=\"text-decoration: underline;\">Human Error<\/span>, James Reason, Cambridge University Press, New York, 1990<\/p>\n<p><a name=\"note2\"><\/a><sup>2 <\/sup>p. 62<br \/>\n<a name=\"note3\"><\/a><sup>3<\/sup> p. 64<br \/>\n<a name=\"note4\"><\/a><sup>4<\/sup> p. 69<\/p>\n<\/div>\n<\/div>\n<div class=\"translate_block\" style=\"display: none;\">\n<hr class=\"translate_hr\" \/>\n<a class=\"translate_translate\" id=\"translate_button_post-83\" lang=\"en\" xml:lang=\"en\" href=\"javascript:show_translate_popup('en', 'post', 83);\"><span>Translate<\/span><\/a><img data-recalc-dims=\"1\" src=\"https:\/\/i0.wp.com\/www.alephnaught.com\/Blog\/wp-content\/plugins\/google-ajax-translation\/transparent.gif?resize=16%2C16&#038;ssl=1\" id=\"translate_loading_post-83\" class=\"translate_loading colorbox-83\" style=\"display: none;\" width=\"16\" height=\"16\" alt=\"\" \/>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Title: Human Error Author: James Reason Paperback: 316 pages Publisher: Cambridge University Press (October 26, 1990) Language: English ISBN: 052131419 Overview This book is very academic, but does have useful information about the reasons people make mistakes and how to categorize them. This kind of information is crucial for understanding how to make software more [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[3],"tags":[2344,28],"class_list":["post-83","post","type-post","status-publish","format-standard","hentry","category-books","tag-books","tag-business"],"aioseo_notices":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p2w3Qj-1l","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/posts\/83","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/comments?post=83"}],"version-history":[{"count":0,"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/posts\/83\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/media?parent=83"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/categories?post=83"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.alephnaught.com\/Blog\/wp-json\/wp\/v2\/tags?post=83"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}