carfield.com.hk design.txt 2024-03-07T12:08:18Z 2024-03-07T12:08:18Z <br/><a href="http://www.inside.com.tw/2012/10/11/design-thinking">http://www.inside.com.tw/2012/10/11/design-thinking</a> <br/><br/>Forum should not present like a tree - <a href="http://www.codinghorror.com/blog/2012/12/web-discussions-flat-by-design.html">http://www.codinghorror.com[..]2/12/web-discussions-flat-by-design.html</a> <br/><br/>How Google change their UI - <a href="http://www.theverge.com/2013/1/24/3904134/google-redesign-how-larry-page-engineered-beautiful-revolution">http://www.theverge.com[..]rry-page-engineered-beautiful-revolution</a> <br/><br/>挑剔的老闆與 Square Cash 背後的設計故事 <a href="http://www.inside.com.tw/2013/11/08/how-square-designed-a-product-with-no-design-at-all">http://www.inside.com.tw[..]designed-a-product-with-no-design-at-all</a> <br/><br/>In other words, a feeling of affinity with others. - <a href="http://www.targetprocess.com/blog/2013/11/ux-the-art-of-empathy.html">http://www.targetprocess.com[..]/blog/2013/11/ux-the-art-of-empathy.html</a> <br/><br/><a href="http://www.uisdc.com/different-ways-product-design">http://www.uisdc.com/different-ways-product-design</a> <br/><br/><a href="http://www.targetprocess.com/blog/2015/07/minimal-action-energy-principle-in-user-interface-design.html">http://www.targetprocess.com[..]-principle-in-user-interface-design.html</a> <br/><br/>16 little UI design rules that make a big impact - <a href="https://uxplanet.org/16-ui-design-tips-ba2e7524d203">https://uxplanet.org/16-ui-design-tips-ba2e7524d203</a> <br/><br/>Watching Susan Kare explain the Mac UX in 1984 is the most relaxing thing ever - <a href="https://www.fastcompany.com/91044923/watching-susan-kare-explain-the-mac-ux-in-1984-is-the-most-relaxing-thing-ever">https://www.fastcompany.com[..]-in-1984-is-the-most-relaxing-thing-ever</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2024-03-07T12:08:18Z focus.txt 2023-08-15T13:55:04Z 2023-08-15T13:55:04Z <br/>Don't steal user's focus - <a href="http://www.codinghorror.com/blog/archives/001011.html">http://www.codinghorror.com/blog/archives/001011.html</a> <br/><br/>Vertical vs. Horizontal Cards: Which Are Better? - <a href="https://uxmovement.medium.com/vertical-vs-horizontal-cards-which-are-better-4ee8ba1f868d">https://uxmovement.medium.com[..]ntal-cards-which-are-better-4ee8ba1f868d</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2023-08-15T13:55:04Z ui concept.txt 2016-02-03T15:19:47Z 2016-02-03T15:19:47Z <br/><a href="http://www.infoq.com/presentations/New-Rules-for-Good-UI-Design">http://www.infoq.com/presentations/New-Rules-for-Good-UI-Design</a> <br/><br/>Explanation of using Grid - <a href="http://www.subtraction.com/pics/0703/grids_are_good.pdf">http://www.subtraction.com/pics/0703/grids_are_good.pdf</a> <br/><br/>Combine the power of camera and touch screen - <a href="http://link.brightcove.com/services/player/bcpid932579976?bclid=932553050&bctid=933742930">http://link.brightcove.com[..]32579976?bclid=932553050&bctid=933742930</a> <br/><br/>Keep consistency is nice for most of the time, but there is exception, here is a example and argument about this - <a href="http://www.37signals.com/svn/posts/628-iphone-context-over-consistency">http://www.37signals.com[..]osts/628-iphone-context-over-consistency</a> <br/><br/>Good ui check-link:<br/><br/>Considerate software takes an interest <br/>Considerate software is deferential <br/>Considerate software is forthcoming <br/>Considerate software uses common sense <br/>Considerate software anticipates needs<br/>Considerate software is conscientious <br/>Considerate software doesn't burden you with its personal problems <br/>Considerate software keeps you informed <br/>Considerate software is perceptive <br/>Considerate software is self-confident <br/>Considerate software doesn't ask a lot of questions <br/>Considerate software takes responsibility <br/>Considerate software knows when to bend the rules<br/><br/><a href="http://www.codinghorror.com/blog/archives/000550.html">http://www.codinghorror.com/blog/archives/000550.html</a> <br/><br/><br/>• Good design is innovative.<br/>• Good design makes a product useful.<br/>• Good design is aesthetic.<br/>• Good design helps us to understand a product.<br/>• Good design is unobtrusive.<br/>• Good design is honest.<br/>• Good design is durable.<br/>• Good design is consequent to the last detail.<br/>• Good design is concerned with the environment.<br/>• Good design is as little design as possible.<br/><br/><a href="http://gizmodo.com/343641/1960s-braun-products-hold-the-secrets-to-apples-future">http://gizmodo.com[..]oducts-hold-the-secrets-to-apples-future</a> <br/><br/>Principle #1. If a user is new to a product, “why” overrules “how to”<br/>Principle #2. If all’s OK with “why”, give a clear “how to” right in the screen - See more at: <a href="http://www.targetprocess.com/blog/2014/01/2-meta-principles-for-user-interface-writing.html">http://www.targetprocess.com[..]inciples-for-user-interface-writing.html</a> <br/><br/><a href="http://99designs.com/designer-blog/2014/01/15/7-unbreakable-laws-of-user-interface-design/">http://99designs.com[..]breakable-laws-of-user-interface-design/</a> <a href="http://www.inside.com.tw/2014/01/21/7-unbreakable-laws-of-user-interface-design">http://www.inside.com.tw[..]nbreakable-laws-of-user-interface-design</a> <a href="http://www.inside.com.tw/2016/01/31/ui-vs-ux-whats-the-difference">http://www.inside.com.tw/2016/01/31/ui-vs-ux-whats-the-difference</a> <br/><br/><br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2016-02-03T15:19:47Z menu.txt 2015-12-14T03:21:43Z 2015-12-14T03:21:43Z <br/><a href="http://www.nngroup.com/articles/menu-design/">http://www.nngroup.com/articles/menu-design/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2015-12-14T03:21:43Z fonts.txt 2014-12-20T09:19:26Z 2014-12-20T09:19:26Z <br/>Resource concern about font design<br/><br/>The arguement that font display in MS Windows is better than Mac - <a href="http://www.codinghorror.com/blog/archives/000885.html">http://www.codinghorror.com/blog/archives/000885.html</a> <br/><br/>How to measure if font is better design or not - <a href="http://www.codinghorror.com/blog/archives/000930.html">http://www.codinghorror.com/blog/archives/000930.html</a> <br/><br/>Font design - <a href="http://www.codinghorror.com/blog/archives/001038.html">http://www.codinghorror.com/blog/archives/001038.html</a> <br/><br/><a href="http://www.inside.com.tw/2014/03/19/popular-typography">http://www.inside.com.tw/2014/03/19/popular-typography</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2014-12-20T09:19:26Z tools.txt 2014-04-03T07:02:16Z 2014-04-03T07:02:16Z <br/>How to work effectively with UI builder - <a href="http://codesheriff.blogspot.co.il/2014/03/8-tips-for-working-effectively-with.html">http://codesheriff.blogspot.co.il[..]8-tips-for-working-effectively-with.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2014-04-03T07:02:16Z textbox.txt 2013-01-30T15:21:09Z 2013-01-30T15:21:09Z <br/>Single form for credit card input - <a href="http://www.inside.com.tw/2012/12/26/square-s-smart-form">http://www.inside.com.tw/2012/12/26/square-s-smart-form</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2013-01-30T15:21:09Z button.txt 2013-01-26T12:45:16Z 2013-01-26T12:45:16Z <br/>Where should OK button put? <a href="http://www.inside.com.tw/2013/01/23/app-dialog-button-design-should-yes-be-right-or-left">http://www.inside.com.tw[..]utton-design-should-yes-be-right-or-left</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2013-01-26T12:45:16Z registration.txt 2013-01-26T11:24:21Z 2013-01-26T11:24:21Z <br/>There should be service before registration - <a href="http://www.inside.com.tw/2013/01/22/mobile-sign-up-forms-must-die">http://www.inside.com.tw/2013/01/22/mobile-sign-up-forms-must-die</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2013-01-26T11:24:21Z prototype.txt 2012-09-26T15:04:45Z 2012-09-26T15:04:45Z <br/>A blog - <a href="http://www.codinghorror.com/blog/archives/001091.html">http://www.codinghorror.com/blog/archives/001091.html</a> and a book - <a href="http://books.google.com/books?hl=en&id=5OhE7dyGtmgC&printsec=frontcover&source=web">http://books.google.com[..]E7dyGtmgC&printsec=frontcover&source=web</a> <a href="http://www.paperprototyping.com/">http://www.paperprototyping.com/</a> <br/><br/>How to do a good prototype - <a href="http://tynerblain.com/blog/2010/10/25/a-prototype-is-worth-a-kloc/">http://tynerblain.com[..]/2010/10/25/a-prototype-is-worth-a-kloc/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2012-09-26T15:04:45Z page.txt 2012-04-01T12:37:09Z 2012-04-01T12:37:09Z <br/>Is paging necessary at all? <a href="http://www.codinghorror.com/blog/2012/03/the-end-of-pagination.html">http://www.codinghorror.com[..]/blog/2012/03/the-end-of-pagination.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2012-04-01T12:37:09Z usabilities.txt 2012-02-20T16:56:36Z 2012-02-20T16:56:36Z <br/>Few books of UI design - <a href="http://www.keepitusable.com/blog/?p=46">http://www.keepitusable.com/blog/?p=46</a> <br/><br/>Eight Problems That Haven't Changed<br/><br/><a href="http://www.hotwired.com/webmonkey/templates/print_template.htmlt?meta=/webmonkey/06/24/index4a_meta.html">http://www.hotwired.com[..]?meta=/webmonkey/06/24/index4a_meta.html</a> <br/><br/>A discussion about if web UI will take over tradition Desktop UI, attracting a lot of discussion - <a href="http://www.codinghorror.com/blog/archives/000815.html">http://www.codinghorror.com/blog/archives/000815.html</a> <br/><br/>Also from same blog, discussion of how to have nice 404 page - <a href="http://www.codinghorror.com/blog/archives/000819.html">http://www.codinghorror.com/blog/archives/000819.html</a> <br/><br/>Why we need to make application easy? Because no one read or follow manual, they just follow what they feel ok - <a href="http://www.codinghorror.com/blog/archives/001048.html">http://www.codinghorror.com/blog/archives/001048.html</a> <br/><br/>Browse without mouse - <a href="http://www.codinghorror.com/blog/archives/001057.html">http://www.codinghorror.com/blog/archives/001057.html</a> <br/><br/>We should not listen to user, but watch them - <a href="http://www.codinghorror.com/blog/archives/001063.html">http://www.codinghorror.com/blog/archives/001063.html</a> <br/><br/>Importance of location of icons - <a href="http://fishbowl.pastiche.org/2008/04/03/firefox_bug_426702">http://fishbowl.pastiche.org/2008/04/03/firefox_bug_426702</a> <br/><br/>I think it all apply to normal GUI application also - <a href="http://line25.com/articles/10-usability-crimes-you-really-shouldnt-commit">http://line25.com[..]bility-crimes-you-really-shouldnt-commit</a> <a href="http://www.bootstrike.com/Articles/DesignMistakes/">http://www.bootstrike.com/Articles/DesignMistakes/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2012-02-20T16:56:36Z window.txt 2012-02-20T16:30:03Z 2012-02-20T16:30:03Z <br/>Arguement of how the maximum button behave - <a href="http://www.codinghorror.com/blog/archives/000912.html">http://www.codinghorror.com/blog/archives/000912.html</a> <br/><br/><a href="http://www.developsense.com/blog/2012/02/do-not-close-this-window/">http://www.developsense.com[..]m/blog/2012/02/do-not-close-this-window/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2012-02-20T16:30:03Z sorting.txt 2011-10-26T16:01:14Z 2011-10-26T16:01:14Z <br/>Show a design of how to write a map that store data at disk and do sorting - <a href="http://mattfleming.com/node/53">http://mattfleming.com/node/53</a> <br/><br/>User friendly sort , "100" should be sort after "10" - <a href="http://www.codinghorror.com/blog/archives/001018.html">http://www.codinghorror.com/blog/archives/001018.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2011-10-26T16:01:14Z sale.txt 2011-05-14T18:38:24Z 2011-05-14T18:38:24Z <br/>Many persons think sales appeal and appearance are synonymous, but they are not. Sales appeal is an elusive, psychological value. - <a href="http://jchyip.blogspot.com/2006/10/dreyfuss-five-point-formula.html">http://jchyip.blogspot.com[..]2006/10/dreyfuss-five-point-formula.html</a> <br/><br/>The Iceberg Secret, Revealed, how to present UI to user / customer - <a href="http://www.joelonsoftware.com/articles/fog0000000356.html">http://www.joelonsoftware.com/articles/fog0000000356.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2011-05-14T18:38:24Z signup.txt 2008-04-18T01:56:28Z 2008-04-18T01:56:28Z <br/>Some mistake of signup:<br/><br/>Having a sign-in in the first place<br/>Requiring sign-in too soon<br/>Not stating the benefits to registering<br/>Hiding the sign-in button<br/>Not making "Create a New Account" or "Forgot Your Password" a button or link<br/>Not providing sign-in opportunities at key locations<br/>Asking for too much information when registering<br/>Not telling users how you'll use their information<br/>Not telling the users the requirements for username and password up front<br/>Requiring stricter password requirements than the NSA<br/>Using challenge questions they won't remember in a year<br/>Not returning users to their desired objective<br/>Not explaining if it's the username or password they got wrong<br/>Not putting a register link when the sign-in is in error<br/>Not giving the user a non-email solution to recover their password<br/>Requiring more than one element when recovering password<br/><br/><a href="http://jchyip.blogspot.com/2008/04/16-design-mistakes-for-account-sign-in.html">http://jchyip.blogspot.com[..]design-mistakes-for-account-sign-in.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2008-04-18T01:56:28Z hardware.txt 2008-01-10T12:37:40Z 2008-01-10T12:37:40Z <br/>Discussions if mouse is faster or keyboard is faster, some research showing that shortcut is just make you feel faster... not really agree that personally... <a href="http://daringfireball.net/2008/01/where_keyboard_shortcuts_win">http://daringfireball.net/2008/01/where_keyboard_shortcuts_win</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2008-01-10T12:37:40Z date widget.txt 2007-11-28T06:31:43Z 2007-11-28T06:31:43Z <br/>Date widget should support term like "yesterday" , "tomorrow", .... - <a href="http://ajaxian.com/archives/mad-cool-date-library">http://ajaxian.com/archives/mad-cool-date-library</a> <a href="http://www.datejs.com/">http://www.datejs.com/</a> <a href="http://code.google.com/p/datejs/">http://code.google.com/p/datejs/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2007-11-28T06:31:43Z undo.txt 2007-11-12T03:25:02Z 2007-11-12T03:25:02Z <br/>Much better than warning dialog in many cases - <a href="http://www.alistapart.com/articles/neveruseawarning">http://www.alistapart.com/articles/neveruseawarning</a> <a href="http://www.dancingmango.com/blog/2007/10/22/confirmation-undo/">http://www.dancingmango.com/blog/2007/10/22/confirmation-undo/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2007-11-12T03:25:02Z link.txt 2007-11-05T18:09:54Z 2007-11-05T18:09:54Z <br/><a href="http://www.codinghorror.com/blog/archives/000985.html">http://www.codinghorror.com/blog/archives/000985.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2007-11-05T18:09:54Z visualization.txt 2007-08-09T02:44:36Z 2007-08-09T02:44:36Z <br/>Introduction of various visualization technique<br/><br/><a href="http://www.codinghorror.com/blog/archives/000926.html">http://www.codinghorror.com/blog/archives/000926.html</a> <br/><a href="http://www.visual-literacy.org/periodic_table/periodic_table.html">http://www.visual-literacy.org/periodic_table/periodic_table.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2007-08-09T02:44:36Z table.txt 2007-07-10T13:11:09Z 2007-07-10T13:11:09Z <br/>Improve the design of table step by step - <a href="http://www.richardoneill.com.au/articles/improving_the_user_interface/">http://www.richardoneill.com.au[..]u/articles/improving_the_user_interface/</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2007-07-10T13:11:09Z complicated.txt 2006-11-30T16:43:11Z 2006-11-30T16:43:11Z <br/>This blog posting an example to show a bad design from a programmer but not designer - <a href="http://www.codinghorror.com/blog/archives/000734.html">http://www.codinghorror.com/blog/archives/000734.html</a> <br/><br/>I personally think this is true, as programmer need to focus on the system level more. Of course he also have the responsiblities on the UI, but it probably better to have somebody else helping him on that<br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2006-11-30T16:43:11Z form.txt 2006-11-08T06:26:56Z 2006-11-08T06:26:56Z <br/>A form in nice user interfacce<br/><br/><a href="http://paularmstrongdesigns.com/examples/css/awesome-form.html">http://paularmstrongdesigns.com/examples/css/awesome-form.html</a> <br/><br/>And a simpler one - <a href="http://www.quirksmode.org/css/forms.html">http://www.quirksmode.org/css/forms.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2006-11-08T06:26:56Z nice comment about nokia phone.txt 2006-04-16T10:08:09Z 2006-04-16T10:08:09Z <br/>They need normal button and easy remember name: <a href="http://www.russellbeattie.com/notebook/1008972.html">http://www.russellbeattie.com/notebook/1008972.html</a> <br/><br/><script type="text/javascript"><!--google_ad_client = "pub-9426659565807829";google_ad_slot = "9359905831";google_ad_width = 728;google_ad_height = 15;//--></script><script type="text/javascript" src="http://pagead2.googlesyndication.com/pagead/show_ads.js"></script> 2006-04-16T10:08:09Z