METU - CC : Web Site Usability

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Web Site Usability

Web site usability is defined as "the extent to which a site can be used by a specified group of users to achieve specified goals with effectiveness, efficiency, and satisfaction in a specified context of use". This definition implies that usability is user and task dependent, as well as being related to how well the user is able to accomplish what they set out to do, how efficiently the user can do this, and how satisfied the user is during and after the process.

Usability is also defined as a quality attribute that assesses how easy user interfaces are to use and may refer to methods for improving ease-of-use during the design process. Five quality components are suggested for determining the usability of a web site:

Learnability: How easy it is to learn to use?
Rememberability: How easy it is to remember how to use?
Efficiency of use: How much work does it require the user to do?
Reliability in use: Does it work correctly and does it help users perform tasks correctly?
User satisfaction: Is the user generally satisfied as a result of using the site?

Additionally, usability may be broken down into six related but distinct components:

Checkability: The system has or allows checks that ensure the correct information is going in and going out of it.
Confidence: Users have confidence both in their capability to use the system and in the system itself.
Control: Users have control over the operation of the system, particularly of the information fed into and out of the system.
Ease of Use: The system is easy to use.
Speed: The system can be used quickly.
Understanding: The system and its outputs are understandable.

In general, usability is potentially complex and wide ranging, but clearly "user-centered." In evaluating usability, it may be possible to measure each of these components separately or in combination using some form of metric or measure.

References:
[1] Whitehead, C.C., Evaluating Web Page and Web Site Usability. Proceedings of the 44th annual Southeast regional conference ACM-SE 44, March 2006.
[2] Jakob Nielsen's Alertbox, August 25, 2003: Usability 101: Introduction to Usability (http://www.useit.com/alertbox/20030825.html)

Resources on Web Usability:

useit.com: Jakob Nielsen's Website: http://www.useit.com/
Usable Web: http://usableweb.com/
Web usability articles & resources: http://www.webcredible.co.uk/user-friendly-resources/web-usability/
Usability.gov: http://www.usability.gov/
About.com: Web Usability: http://usability.about.com/
Universal Usability: A universal design approach to web usability: http://universalusability.com/
User Interface Blog: Design and Usability of User Interfaces: http://www.user-interface.org/
Usability First: Usability in Website and Software Design: http://www.usabilityfirst.com/
Web Sayfalarında Kullanılabilirliğin Önemi ve Kullanılabilirlik Testleri: http://cisn.odtu.edu.tr/2004-10/kullan1.php [in Turkish]
Kullanılabilirlik - ALTI ÜSTÜ TASARIM: http://www.altiustutasarim.com/arsiv/kullanilabilirlik/ [in Turkish]

In order to improve the usability and the accessibility of web sites maintained by the administrative and academic units at METU, several criteria have been developed which are suggested to be complied with. These criteria are developed by METU Computer Center using various resources on usability and accessibility existing on the Web:

	Usability and accessibility criteria	Explanation
1	Does it have the METU emblem?	On a unit’s web pages a there should be a standard METU logo placed to stand for the hierarchical connectivity. Those units which do not have an embedded appropriately featured METU logo could make use of the METU logo of various sizes at the http://www.odtu.edu.tr/about/emblem.php address.
2	Is there a link to the METU main page?	There should be a link to the main page oh METU on the web pages of any unit in order to stand for the hierarchical connectivity.
3	Is there an organizational chart?	In order to give a view of the organizational structure of the unit to the users, there should be an organizational chart placed on the web pages.
4	Is there an e-mail list of the staff?	The e-mail addresses of the staff should be indicated so as to access the staff easily and rapidly.
5	Is there a list of the phone numbers of the staff?	The phone numbers of the staff should be indicated so as to access the staff easily.
6	Is there an e-mail list of the services units?	If there are sub services units in the organizational chart, the e-mail addresses of the sub services units should be indicated so as to access them easily and rapidly.
7	Is there a list of the phone / fax numbers of the services units?	If there are sub services units in the organizational chart, the phone / fax numbers (both if possible) of the sub services units should be indicated so as to access them easily and rapidly.
8	Is there a list of the mailing (post) addresses of the services units?	If there are sub services units in the organizational chart, the mailing (post) addresses of the sub services units should be indicated so as to enable users to communicate by post.
9	Has the Web Master’s address been given?	In order for the users to direct questions / problems / point of view to the person(s) responsible of the web page the communication information of the(se) must be indicated on the web pages (preferably an e-mail address).
10	Is there a site map?	A site map that shows the general structure of the information on the pages and the relation between the pages should be designed and made available.
11	Do the pages load quickly?	The time it takes for the elements, such as, texts, images, tables, animations etc, used on the page to appear and to be used after the first click to access the page should be kept to a minimum.
12	Does the site function without any problems and the same on different operating systems (Windows - Linux)?	It is imperative that the web pages function without any problems and the same on different operating systems in order to address the general user mass.
13	Does the site function without any problems and the same for different browsers (Internet Explorer, Netscape, and Mozilla Firefox)?	In order to address the general user mass web pages must function without any problems and the same for different browsers, in other words must comply with web standards. Compliance to web standards can be checked by using the tool at the http://validator.w3.org/ address.
14	Is there consistency of content on the pages?	The contents of the page must be presented to have a consistent style and structure as if prepared by a single person.
15	Do the pages have design consistency?	In order to provide usability the looks of each page must be in harmony with the other pages, the pages must bear coherent design features.
16	Are the background color / script color contrast sufficient?	In order for the presented information to be legible there should be a contrast between them, easily detectable font colors and (neither too small nor too big) sizes must be preferred so that they can be detectable for the majority. In the Web Accessibility regulations version 2.0 prepared by the W3 consortium an algorithm named Luminosity Contrast Ratio to measure contrast values is recommended. To measure these contrast rates the tools named Color Contrast Check, Color Contrast Analyzer may be used.
17	Are the images used clear?	The images used on the pages should have appropriate features of degree of size, quality, clarity, file size, physical dimensions etc. .
18	Does the site have a text version?	A text version of the site has to be available / presented so that the images and / or the information presented by applications like JavaScript can easily be accessed by the impaired users or users who use script based browsers.
19	Are there explanatory tags (bottom) for the pictures that are used in the site?	In order to make it easy on the impaired users or users who use script based browsers to make the most of the pages that have images, picture tags ought to be added to the images.
20	Is the content in a hierarchical structure?	The links presented on the main page have to have a hierarchical structure in order to provide the users easier access to the information (for example, by using a menu grouping the information and indicating the main / sub page headings).
21	Has the scroll bar (facilitating page transition) been minimized?	The scroll bar (facilitating vertical navigation), which forms due to the content, that could have been split, being written one under the other, hinders the usage on some pages. Instead of creating such long pages it is essential to use more pages where the information is separated into several sections or in cases where it is necessary for the content to be on the same page the sub titles to appear at the top of the page as an index.
22	Is there a "Go to Top" link on the pages with vertical navigation?	On the pages where a scroll bar is formed, there should be a "Go to Top" (or some phrase giving the same meaning) link under every section and at the bottom of the page, in order to provide ease of use.
23	Has the urge for horizontal (scroll bar) navigation in a page been avoided?	Defining the size of the tables and images in pixels causes a vertical scroll bar to be formed on some pages during display (in this evaluation study the most common monitor resolution is assumed to be 1024x768). In order to prevent this negative effect, table and image sizes are to be assigned in percentage values as far as possible and checks must be performed in regards to the assumed monitor resolution.
24	Does every page have standard navigation features (means to return to the main page, go to the previous and next pages etc.)?	There should be standard navigation features on every page for the users to navigate easier in the site (for example, every page should have the means to return to the main page, go to the previous and next pages when the need arises). Furthermore, at sites which have many sub headings a menu should designed and it should be made available on every page with the aim of providing ease of navigation.
25	Is it clear on which page of the site the user is?	On which page of the site the user is can be provided by “bread crumbs” e.g. Main page > About > Communication
26	Do the links work?	It is necessary to check the designed web pages regularly and fix the broken links or remove them. The tool at the http://validator.w3.org/checklink address may be used to check whether there is a broken link on the pages or not. (In order for it to check the sub pages that are linked from the main page the option 'Check linked documents recursively' must be selected.)
27	Are the links already visited indicated?	A visual difference between the visited and the unvisited links should be formed so that the users do not get lost in the site.
28	Are the links coherent and easily intelligible?	The links and regular texts should be designated so that they can be differentiated and the users do not get lost in the site.
29	Do the link sentences include pointless phrases like 'Click Here'?	Link sentences must include phrases that give meaningful information about the pages to be linked to.
30	Are the links that are not HTML designated?	Links given for the files with extensions such as .pdf, .doc, .xls etc. must be designated in such a manner to differentiate them.
31	Are the URLs intelligible and user friendly?	Intelligible URLs provide ease of usage (a lousy example: www.odtu.edu.tr/index.php?a=9&b=9&sayfa=about; a good example: www.odtu.edu.tr/about/)
32	Are the titles of the HTML pages explicative?	The heading information to be entered in the "title" tag of the browser, since it is listed on the search engine page when a search is conducted, should be well explanatory in order to facilitate easy access.
33	Can a printout be taken direct from a printer?	Care must be taken that there are two different ways to obtain a printout from web pages according to a user’s preference. Some users may choose to get a printout of the whole page, whereas, others may wish to get a printout of just the info given on the page (the content, excluding the features like the menus, header images, etc.). Therefore the pages should be designed to facilitate both choices; getting a printout of the whole page without any problems when the "Print" option of the browser software is clicked on, as well as getting a printout of the content presented on the page when the "Print" (or some other similar phrase) button on the page itself is clicked on.
34	Can the content be accessed with a minimum number of steps?	In order for the aimed information to be reached at in the easiest and the most rapid manner, a minimum number of sub hierarchy must be used in the structure of the content any info should be made accessible in at most three steps.
35	Is there a search facility according to a key word?	Specifically for pages with populated information, a search engine, that could be used to search according to a key word, should be coupled to be used in order to facilitate for quick and easy access to the aimed information.
36	If there is a search tool, can it be reached easily?	A search tool should be at a location where it can be easily accessed.
37	Is the language used (Turkish / English) proper?	Care must be taken not have grammar and spelling mistakes in the content of the page.
38	Is the information updated?	In order to present correct and complete information to the users the contents of the pages must be up to date and must be checked regularly. When evaluating web pages, the dates under the titles like announcements and activities are to be observed and the currency of the content is to be considered. The related unit is recommend to review how updated the information is.
39	Has an update date been given?	It is important that the date of last update be indicated so that the users can have an idea of the currency of the information provided on the site.
40	Is there a link to the other related pages?	It is recommend that the units give links about the other web pages related to their field of activities and direct the users accordingly. There should be no place on the unit pages for links that have no relation to their field of activity.
41	Have spam filtering measures been taken at the e-mail addresses given?	E-mail addresses displayed on the pages should not be openly designated, to reduce the probability of spam messages that may be sent. If possible, the tag mailto: should be removed and for the “@” character an image or an alternative character (e.g. at) should be utilized.
42	If there exists a web form to be filled in, are there alerts and designations to provide correct entry?	Warnings to prevent users from making mistakes ought to be given before the form is filled out. The expressions on the form and the form alert messages should be intelligible. After the form is filled in and sent the user must be informed about the form being sent successfully.
43	Is there the other language version?	It is imperative that an English version of the web pages prepared in Turkish is also available since the medium of education at our university is in English and the pages should be able to address foreign students and professors as well as other foreign users. Similarly, those pages that have been prepared in English ought to have Turkish versions to be able to target the users who are monolingual in Turkish.
44	If there is the means of the other language, is the facility of transition provided?	For the sake of usability, the button of transition from the Turkish or the English page to the page prepared in the other language should be made available on the page.
45	Is a virtual domain name defined?	Virtual domain names must be defined for web pages with long and complicated addresses, in order to facilitate users to access them easily and to be recalled at a snap. In accordance with the scope of METU central informatics virtual domain name standards the domain names in question are defined in the www.ECS_CODE.metu.edu.tr format. (ECS stands for Electronic Communication System)
46	Are there any pages "at the stage of being constructed"?	The number of pages under construction must be reduced to a minimum or if the preparation of the pages under construction are to take a longer time, better yet, such pages should not be linked before completion.
47	Is there an alert page specific to the design of the site?	A directive 404 page prepared for the pages that can not be found will prevent the users from thinking that the site is out of order and convince them to tag along.
48	Does the site have any favicons?	With the new structure of the browsers, favicons with extra tabs are very useful for the users who make use of the site.