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Abstract—In this document will be exposed the basic points about web usability, and will be content too a small comparative study in two web sites to explain in a practical way who to measure the usability of a site.

Index: Web Usability, Web Accesibility, internet, e-business.

I.INTRODUCTION

OW, when internet has become one daily thing for a great amount of people around the world, and the

computer networks are around us everywhere you look, is when something so crucial as the way the people understanding and the way they deal with the web sites is becoming a crucial issue for all the web sites developer. "Twenty-eight percent of Web site transactions result in consumer failure and frustration.... Six percent of users who leave a Web site in frustration say they won't return to the site or patronize the company” [1].

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The previous statement gives us a clue about why is the usability a crucial matter for the web sites designers. But, what is the meaning of usability? Usability is a quality attribute that assesses how easy user interfaces are to use. The word "usability" also refers to methods for improving ease-of-use during the design process [3]. For web usability ISO give us their definition: "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" [2].

Jacob Nielsen speaking About Usability said that there are five main points that will help to define and quantify it: Learnability, Efficiency, Memorability, Errors, Satisfaction [3]. These five points are a simple path to follow if you want to know if some environment is usable. But maybe these characteristics are a bit abstract to quantify the usability of a site, because they depend in the appreciations of the users, and in their experience dealing with web environments.

Nakamichi et al in the paper Detecting Low Usability Web Pages using Quantitative Data of Users' Behavior give a look at some concrete way to measure the usability of a web site. They experimented to investigate the relation between quantitative data viewing users' behavior and web usability evaluation by subjects for detecting low usability Web pages [4]. This method, is based in the behavior of the users when deal with a determinates environment, but once again it depend in the familiarity of the users have with the navigation through the internet.

Ivory et al prefer basing the measures of the usability in metrics based in the way the web is designed, not in the way the user perceive it.

Manuscript received May 2, 2008. M. Albalá López student at NEWI (e-mail: maalbala@ gmail.com).

On my point of view the best way to look for a usable web site is to know how the users deal with the environment. But to test it is important the people who are chosen to be used as a user tester, because the background in acknowledge of these tester must be in the average of the most of the possible users of the site. If this condition is not taken in account, the study of the usability of the site could be compromised.

II.USABILITY TESTING

Battleson et al. claim that usability testing is the most effective way to asses a site's usability. They go on to specify three categories of usability testing: inquiry, inspection, and formal usability testing [5].

In performing quantitative usability testing, Ivory, et al. suggest the following Web page metrics as the most important in evaluating usability [6]:

• Word Count--Total words on a page • Body Text %--Percentage of words that are body vs.

display text (i.e., headers)• Emphasized Body Text %--Portion of body text that

is emphasized (e.g., bold, capitalized or near !'s) • Text Positioning Count--Changes in text position

from flush left • Text Cluster Count --Text areas highlighted with

color, bordered regions, rules or lists • Link Count--Total links on a page • Page Size--Total bytes for the page as well as

elements graphics and stylesheets • Graphic %--Percentage of page bytes that are for

graphics • Graphics Count--Total graphics on a page (not

including graphics specified in scripts, applets and objects)

• Colour Count--Total colours employed • Font Count--Total fonts employed (i.e., face + size

+ bold + italic) These are metrics based in the appearance of the web

used to quantify the usability of the site. But Nakamichi et al propose metric based in the behaviour of the user when uses a web site to measure the usability of it. These measures are [4]:

• Browsing time (sec): Time since the user begins to see a certain page, until it changes to another page

• Moving distance of mouse (pixel): Moving distance of the mouse cursor on a screen

• Moving speed of mouse (pixel/sec) = Moving distance of mouse / Browsing time

• Wheel rolling (Delta): the amount of wheel rolling of a mouse

• Moving distance of gazing points (pixel): Moving distance of gazing points on a screen

A Web Usability Study (Apr 2008)

First M. Albalá López, Student, NEWI

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• Moving speed of gazing points (pixel/sec) = Moving distance of gazing points / Browsing time

III.BENEFITS

The benefits derived of improving the usability of a particular web sites are based in the easiness that the users of the site experiment when deal with it. The more comfortable way to deal with the site, could for example, derives in a increase of the sales though this web site, or it could transform a intranet environment from an unused and obsolete one in great path of communication between the employers and the company, or among the departments of it, deriving in benefits of time and money.

IV.CASE OF STUDY

In this section will be analyzed two web sites Astroc and Ferrovial. These web sites are from two companies in the building business. The choose of these examples to explain the usability of a web site is because the two of them are oriented to the same kind of public, the two of them are in the same business field too, and is obvious that one of them are a lot more usable than the other one.

For the study of the usability of these two web sites we will go through ten questions. These are simple questions that give us an overview about the usability of the site. These questions are based in the way the users could perceive the environment, and the facilities that the sites give to the navigation trough them. Maybe, these ten questions, could be adapted to make studies with a small groups of users of the web sites that are designed in order to test the usability of the sites before the development end. From my point of view, this is a very interesting thing, because if the usability of the site is tested before his develop ends, all the usability errors could be solve saving money and time for the company [7].

A.From my point of view, is he legibility of the information adapted?

Yes, in general, both of them have the information adapted to the usual users of the pages, and the choose of the colours of the fonts are well adapted to help the read of it. Perhaps the Astroc case, the colour of the font in some of the sections of the web difficult the read of it, but this don’t happen in the whole site.

Possible a good choose of the font and background colour is the Ferrovial one, grey over white, it helps to make the site more accessible and usable.

B.Are well defined, the sections of the web?

Yes, in general, all the sections are well defined. But in the Astroc case, some times, the names of the sections induce to an error. This makes that though the navigation in this site, when the user is looking for a concrete data, he inquires in a lot of error before reach his goal.

C.Is it evident the profundity of the contents tree?

In the Ferrovial case yes, it is evident the profundity of the contents tree, because in the left margin of the page there are a menu that indicates the tree of contents, and you know in each moment where you are, and the depth in the contest tree here is the section in what you are. But in the Astroc case it

is not evident the profundity of the contents tree. In the site are no references about the depth of the sections, and some times, in the drop down menus looks like the profundity will be minor than in fact is. Then the user does not know in any moment what is the depth of the contents tree.

D.Are the names of the links clearly identifying the contents of each section?

In the Ferrovial case the names identifying perfectly the contents, and permit to find the information needed in a small amount of time. All the names are well chosen, this makes the navigation very intuitive. When a concrete data is looking for, the users do not commit significant amount of errors in their seek. On the other hand, in the Astroc case the names do not identify clearly what is the information in each section, it makes that looking for a concrete data will be a tedious search. This repels on difficult very much the navigation of the users.

E.Are there enough helps to the navigation?

In the Ferrovial web site could be found different services that help in the navigation. This services are: the contents tree in the left margin of the site, that help the user jump though the sections in the site without has to return to the main page. The position on the contents tree where the user is, indicated by the bar in the top of the centre of the site, helping the user to be allocated in the contents tree. The finder situated in the right of the bar in the centre section of the site that help the user to seek key words. In the press release section has an advanced finder to seek trough all the information in this section. On the contrary in Astroc site there are no big things that simplify the navigation, and the drop down menus, without all the sections displayed in it difficult the labour to find concrete data in the site.

F.When dealing with different web browsers. Are the appearance and the functionality similar in all of them?

Yes, with different browsers the appearance and functionality are similar. I use to this question three different web browsers, Safari, Internet Explorer, and FireFox, I did not found any difference in the navigation and in the aspect of the sites.

G.Are there any elements that difficult the navigation?

In the Ferrovial one there are no elements that difficult the navigation. The way to navigate though this site is very intuitive, and there are no need to make a lot of steps when you are jumping among the different sections of the site. But in the Astroc one, the drop-down menus of this page, difficult the navigation trough the web because the excessive animation when these menus are displayed. In addition, the great amount of pictures displayed as background on some of the sections turn aside the attention from the data contented in it.

H.Are there elements that distract me from the navigation?

In the Ferrovial case I do not think that there are any elements which difficult the navigation. As said previously, the navigation is very intuitive and the site has a lot of helps to the navigation. In the Astroc case the drop-down menus, as in the previous question is said, distract from the navigation.

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The excessive animation of the page turns aside the attention of the user and difficult the navigation.

I.Do I have to make a lot of steps to reach the information that I am looking for?

In Ferrovial site there are no need to make a lot of steps to reach concrete data because of the menu in the left side makes the navigation agile. It has direct access to every section on the web. On the other hand in the Astroc site you need to realize a lot of steps to reach one concrete section because, as said previously the names aren’t very identify, and there are no way to go directly to the information searched.

J.Do I think that the usability of the web is good?

As a conclusion for this study, in my opinion, the Ferrovial site has, in general, a notable grade of usability. I do not find anything that makes this site unusable. But the one of Astroc, despite the fact that it has a very good presentation due to the animations in the whole site, as could be deduced from the previous questions, is not very usable at all. It has a great amount of design deficiencies that make it has a bad grade of usability.

V.CONCLUSION

Test the usability of a site is very easy when you know a little about the matter. Perhaps if you have not a lot of acknowledge in the issue you could not make a depth test of the site usability, but the basic points of this subject are derived from common sense. It is very important take the usability matter in consideration when a web site is developed, because this issue will be of great importance in the exit or the failure of the site. If a site is not usable the users will look for another one more usable and the site will become a failure. Now that the e-business is an important factor in the business market, make the web sites as usable as possible will extend the horizons of a company. Because if one site is not usable, it is sure that another site in the same business field will be usable, and the best usable one will be the one that will reach the market expectations, and in consequence the one that will make more money. Some big companies is now, when they see that their competitors earn more money though their sites, when they start to look about the usability of their sites. If a company improve the usability of his site, it will derive in economic benefits, not only through the possibility of selling his services though internet, as also in make new customers though the web site.

REFERENCES

[1] Shacklett, M. Gauging Web site performance. Credit Union Magazine, 67, 6, 2001, 60-62.

[2] Powell, T. A. Web Design: The Complete Reference. Berkeley, CA: Osborne/McGraw-Hill, 2000.

[3] J. Nielsen. (2005, Aug). Usability 101: Introduction to Usability. Useit.com [Online]. Available: http://www.useit.com/alertbox/20030825.html

[4] Nakamichi, N., Shima, K., Sakai, M., and Matsumoto, K. (2006, May). Detecting low usability web pages using quantitative data of users' behavior. In Proceedings of the 28th international Conference on Software Engineering (Shanghai, China). ICSE '06. ACM, New York, NY, 569-576. Available: http://doi.acm.org/10.1145/1134285.1134365

[5] Battleson, B., Booth, A., & Weintrop, J. Usability testing of an

academic library Web site: A case study. Journal of Academic Librarianship, 27, 3, 2001, 188-198.

[6] Ivory, M. Y., Sinha, R. R., & Hearst, M. A. Empirically Validated Web Page Design Metrics. ACM SIGCHI'01, 2001.

[7] Moratilla, A. (2006, May). Ayuda para el test de usabilidad y accesibilidad. Notes from the module Diseño de Aplicaciones Web from the Universidad de Alcalá de Henares. Available: http://www.multimedia.uah.es/encuestausabilidad/faq.html

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