Articles for the Month of October 2010

Interview with Bob Regan on accessibility of Macromedia

Bob Regan is the Accessibility Product Manager at Macromedia, creators of high profile products including Dreamweaver, Flash and Director. I spoke to him recently to see what’s happening at Macromedia with regards to Accessibility. 

When I was a doctoral student at the University of Wisconsin, I was in charge of web design instruction for faculty and staff. In late 1999, the university adopted a policy on web accessibility. At that point, I not only had to learn about accessibility myself, I had to teach it to the faculty at the UW. 

The more I got involved in the issue, the more I found it lined up with my interests as a teacher and as a researcher. Accessibility combines technology with issues of inclusion in ways that I found quite compelling. I soon changed my research field to align with the work I was doing in accessibility. 

At the same time, I took a grounded approach to accessibility. Rather than teaching the technical aspects of the standards, I re-wrote the training materials we were using for Macromedia. Most of the faculty and staff I was working with were publishing or maintaining sites, but did not even know HTML. The technical requirements of the W3C guidelines were often very hard for faculty to understand. So I integrated the concept into the non-technical training we had been delivering before. This made accessibility a much more ‘accessible’ topic for many of our faculty. 

Almost two years. A representative from Macromedia came to visit the UW and heard about our work in accessibility. I was hired a few weeks after that. 

One of the amazing things I learned about Macromedia when I first joined was how pervasive thinking was about accessibility. The Dreamweaver team had been thinking about accessibility since Dreamweaver 3. The product manager at the time, a woman named Susan Morrow, wrote a manifesto of sorts that outlined the importance of accessibility from a social and economic perspective. 

Just after that, there was a group who was briefly left idle after an acquisition. To fill in the free time before development began on a new product there, the product manager set them to build a plug-in for Dreamweaver similar to the accessibility validation tool known as Bobby. It was the first plug-in of its kind and since then, every major validation company has authored a version of its own for authoring tools. 

Then I met a number of folks who were working to advance the issue on their own, without any fanfare or discussion. The HomeSite product manager had attended a session on accessibility at the National Center for Accessible Media. From that point on, he decided that HomeSite should be an accessible product. 

It was not until Section 508, the US Federal Requirement for government web sites, that Macromedia decided to hire someone to coordinate the issue. I was brought on board just before Section 508 was coming into effect. 

First and foremost, accessibility is the right thing to do. This is a company of individuals who are socially aware and active. Accessibility generates a unique kind of enthusiasm for technology and its potential to make our society a more open and equitable place. 

At the same time, we could not justify our work in accessibility without a strong business model. With the growing number of accessibility policies in the U.S., U.K. and around the world, we strive to make our tools the most accessible on the market. As people come to understand the importance of accessibility, we want them to think of Macromedia tools first. 

Well, there is a difference between the accessibility and the disability communities. They overlap, but they are not synonymous. The accessibility community is a group of folks involved in accessibility standards, developing assistive technologies and ensuring that other technologies interoperate with assistive technologies and standards. These are folks like the W3C’s Web Accessibility Initiative, the Office of the e-Envoy in the UK, tool makers like GW Micro and accessibility managers like myself at companies, universities and government offices. 

The disability communities include groups like the Royal National Institute for the Blind, National Federation of the Blind and the Royal National Institute for the Deaf. These groups frequently have a deep involvement in the accessibility community, but they are not the same thing. 

There is no question that Macromedia would not be as successful as we have been in the area of accessibility without strong ties in the accessibility and disability communities. We invest a lot of our time in listening to our partners, and in helping to build examples of accessible content. 

Macromedia has a strong relationship with the accessibility community through standards work in the W3C and with local government and education. It is important for us to stay involved in these efforts to build support for the standards directly into our tools but also to ask questions within the working groups that help them understand how standards are built into products. I serve on the authoring tools accessibility guidelines working group within the W3C. I am also in regular contact with my colleagues charged with enforcing standards in government departments in the US, the UK, Canada and Australia. 

Within the disability communities, I have regular contact with groups like the National Federation of the Blind in the US, the RNIB in the UK, Vision Australia, Telecommunications for the Deaf and the American Association of People with Disabilities. To address concerns of individuals with disabilities that are not organized into a large umbrella organization, I spend a lot of time with researchers back at the University of Wisconsin where I got my start. 

There are three measures that shape the output of our tools. First, we measure the output of our tools against web and accessibility standards. Second, we check our tools for interoperability with assistive technologies such as screen readers. Third and most importantly, we seek out input from customers with disabilities to collect feedback on our tools. 

We try to incorporate accessibility into every product. However, we are known for our work with Dreamweaver, Flash and Contribute. 

Terrific, but we’re not done yet! Accessibility often involves a complicated process of building in support for accessibility API’s in the OS such as MSAA, assistive technologies and standards. In several instances, the industry has run into some very serious challenges. We are dedicated to continually making our tools better, more accessible and more usable for people with disabilities. 

Are there any areas of Accessibility where your products can produce output that is more accessible than other technologies such as XHTML and CSS? 

Accessibility needs to be understood broadly. For someone who is blind, the most accessible form of content is plain text, perhaps marked up with xhtml and css. However, for someone with a cognitive disability, the least accessible form of content is plain text. 

In order for many forms of content to be truly accessible, they need to be multi-modal. Think of a math course. Imagine trying to understand the concept of a diameter and the relationship to circumference without images. Using rich media technologies such as Flash, a teacher can present this concept interactively that may make the concept more accessible to many students with and without cognitive disabilities. An interactive flash movie may not be the most accessible format for a child who is blind, but that does not mean that it should not be available to child with other disabilities. It only means that it should not be the only means of accessing this content. 

Both Dreamweaver and Contribute have been designed to be tools that can be easily used by people who are blind. We are working now with the National Federation of the Blind to develop tutorials for blind developers to learn html and web design using our tools. 

Yes. Whenever and wherever we can. 

We work to incorporate accessibility into all of our training and documentation materials, we include sessions on accessibility at our own conferences and we deliver sessions at a variety of other conference discussing accessibility. 

Very, very positive. Designers are increasingly required to incorporate accessibility into the specs. We are able to introduce the topic in a manner that is familiar to designers and is consistent with their existing workflow. 

Breeze is currently the most accessible product of its kind on the market. We have worked to ensure that the solution is accessible to people with disabilities by adding in support for screen readers via the Flash player but also via the keyboard to make it easier to control the movie. 

No, but the accessibility of Flash affects the accessibility of Central. At the moment, Central is not accessible, but like all of our products it is a priority. 

Central is not accessible as it uses the standalone Flash player. At the moment, only the ActiveX Flash player is accessible. 

Every product includes a plan for accessibility. We try to consider what use cases are likely for each product and incorporate support where we can. Obviously, the plan for Fireworks is different from the plan for Dreamweaver. However, there is a plan for every product. 

Many thanks to Bob for taking the time to complete this interview, which was in my inbox the day after I sent the questions, very impressive. 

For more information on Accessibility please visit the links on our Disability Discrimination Act page or read my article An Introduction To Accessible Web Design. 

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An introduction to accessible Web design

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Skip to navigation that this article has been published in SitePoint and accessify.com.

Accessibility in Web design addresses the issue of creating Web sites that are accessible to all users, regardless of their physical ability or the way in which you are using the Internet.

This article will present the concepts surrounding accessible Web design, initiatives underway to increase the accessibility of websites and guidelines that you can use to make your site more accessible.

Technical intermediate level: | Date: November 23, 2002 |Author: Nigel Peck

Should not all Web sites accessible? You may be wondering why there is this problem and why all Web sites are no longer accessible to all users.There are a number of reasons I will present now.

Users visually disabled ranging from blind to completely blind color have problems with images that do not provide a textual description of what show. Without a description text users who cannot view an image has no way of knowing what is or what it represents.

These users also have problems understanding that logically are not created when “viewing” using a non-visual browser as a reader pantalla.Un screen reader is a browser that reads aloud Web sites to make Web sites accessible to users with visual disabilities. Often, a website that seems pleasant visually will be a complete disaster when it is heard through a screen reader.

Similarly to users with visual disabilities do not have any way of looking at an image, users with hearing disabilities have no way of understanding that communicates with sound, unless an alternative provided that does not use sound, such as a text description or image information.

If not are physically disabled, have you tried to use a website without the mouse?Unless you were lucky with the site that you choose Next, it was probably very difficult.Physical disabled users are often unable to use a mouse. unless these user requirements are taken into account when creating Web site navigation and physical disabled input method users will sometimes find a completely inaccessible website.

Web sites can be complex, and find the information you want can be difficult for the most capable of nosotros.Esto is not helped by sites that use a design too complex navigation that works differently in different pages (incoherent) and distracting animation repetitiva.Todos these problems are compounded for users with cognitive and neurological disabilities and this makes some completely inaccessible sites for them.

As we have seen, using the Internet if you have a disability can be a difficult task.To observe and understand the guidelines for designing accessible site Web can be produced that serves purpose and is accessible to all users, not only those without disabilities.

But does not stop there.Accessible Web design also has benefits for other usuarios.Vamos to see who can benefit.

The following groups will benefit follow the guidelines for accessible Web site:

Users of mobile phones, Web-TV and kiosks, low-bandwidth users, users in a noisy environment, users with “glow”screen, users that are driving users with a move access level, second language low literacy with different learning styles.

Related accessibility issues also improved:

‘Transmission and maintenance of the site, content andSearching content indexing machines.

There is another reason for its accessible (if you need more) Web site. According to figures current users currently disabled make up approximately 10% to 20% of the population in most of the países.Aumentar quantity of users divided into the categories above and is seeing up to 30% of the mercado.Si make your site accessible to 30% of the market not persuaded that accessible Web design deserves it, then, stop reading now.

It is also increasing the average age of the population in many países.Resultados in a number of issues of accessibility, including vision and hearing expiration changes and changes in the dexterity and the memory.if its market includes a significant number of users older can increase that 30% to a much higher percentage of users who will get the benefits of accessible Web design.

Address accessibility may be a requirement for certain websites, legal.Esto is normally for government sites, but may affect to others, each UK Web site must be accesbile discapacitados.Para discrimination act more information on the requirements in different countries see page W3C policies relating to the accessibility of the Web.

> accessibility initiatives

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“Crawling” search engine

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In this brief article will explain what is understood by a search engine “crawling” or “spidering” your web site.

Technical level: Basic/beginner |Date: November 5, 2002 | Author: Nigel Peck

First a little background about search engines.Search engines are trying to bring order to the chaos that the Internet is esencialmente.Mediante using a search engine you can search web sites related to the chosen topic.

This is done through the introduction of one or more words or phrases that relate to the topic than buscas.Para using a search engine is very simple, it is much harder for the Search Engine.

To give you an idea of the magnitude of the execution of a search engine, Google currently runs on servers of 10,000 and employs 50 or more PHD level software engineers who will be paid with a w2 generator to work constantly on the search engine software.

And what does the software do? we are only considering a small part of it, the part that really comes out and find web pages on the Internet.

A program called the GoogleBot visits your website and reads each page by following the links inside the note sitio.Toma all words used in the pages that can then be used to find the pages to search for these words.

This process is called “crawl” or “spidering” due to the way in which the robot (GoogleBot in this case) finds its way on your site.

This applies not only to the robot for Google; most search engines operate in the same way.

Once GoogleBot has reviewed your site, that information is passed to another part of the software will be to analyze the words and phrases to get them ready to be added to the index.

Once the site has been crawled, just wait for the next Google update.

We offer search engine optimization services.

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An interview with Julie Howell of the RNIB

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Skip to navigation all technical level: |Date: 9 October 2003 |Author: Nigel Peck

Julie Howell is responsible for the development of digital policies for United Kingdom Royal National Institute of blind people. interviewed to him recently about a number of Web accessibility topics.

The part of the DDA affecting the provision of services on the web entered into force on 1 October 1999.

It is true that the Add parties shall enter into force in 2004, but is not parties services provided through the web.Nada effect changes in 2004.

It has definitely made many companies Doha development more aware of the accessibility of the web.But it would be wrong to equate knowledge with growing awareness practice necessarily normas.Mientras compliance is not growing at the same pace.

But keep in mind that the web is still a very new medium for many companies, and disability discrimination legislation is also very nueva.Toma time for companies to digest and application requirements.RNIB is working with many organizations to help them make more accessible the future of their designs. instead of two years I hope the web much more accessible than it is now.

Legislation is never be specific.However, the Disability Rights Commission: code of practice to accompany the Add, published in February 2002, explicitly mentioned services provided via the website as they are covered by the law (an airline online ticketing service is given as an example) .it is no doubt the services offered on the web to qualify as ‘services’ as defined in the Act.

RNIB has recently participated in two of these cases, one of which was the subject of County Court proceedings, and established in July 2003;This is the first legal proceedings we are aware that related in any way the provision of a service on the web.

These cases have already been solved: the clients and the RNIB are content with settlements that have been achieved.

RNIB continue Doha development in particular to the procedures for the issue on behalf of blind and partially sighted people in the courts for breaches of the Act where such offences cannot be solved without such action.

RNIB is currently working on possible cases of accessibility of the Web page on behalf of others blind and visually impaired in Doha development. We are unable to comment on the details of these possible cases at this time, but perhaps might in the future.

Varied. When the dialog begins, often facing enterprises have poorly understood what is meant by accessibility or have been misled about what is needed to make their services accessible online.

It is often an assumption that have to do only the text of his sitio.O any element of the site that are currently in an unreachable area must be alleged eliminarse.Por, nor is it true.

Ounces RNIB Web accessibility team explained the benefits of business of making a site more accessible and have suggested a strategy that works for the company in question (for example, an incremental approach) we find that companies feel much more positive for the task to mano.después all, accessibility is about how to extend the reach of their products and services to a greater number of people and should therefore be considered positively.

Accessibility broadens the scope of our service.makes our interoperable site accessibility.accessibility is a demonstration of our corporate social responsibility.If our competitors are accessible and are not, we can view in a bad light and losing custom.There are more than 8 million disabled people in United Kingdom with a combined purchasing power estimated at £ 45bn per year.accessible design improves for all user experience (e.g. site downloads faster, more technologies are supported).inaccessible sites may be in violation of the law of discrimination of disabled 1995.RNIB works with companies to highlight good practices through stories of positive press and events.If our website is inaccessible, we be excluding future potential workers with disabilities, which is also illegal.accessibility is not about the limitation of the creatividad.El Act working rules and guidelines that include the maximum audience is a very creative process.

Network users blind and visually impaired which I have spoken with are overwhelmingly positive approaches of the Internet and the web at particular.Por therefore is liberating to buy without asking a friend visually impaired to help, or to read the news or a book without the assistance of a person the ability to check train online once vidente.Incluso makes a big difference for a blind you to organise your own trip to a Meeting Manager.

However, many websites still blocked blind and partially sighted people, and I no I exaggerate frustration and disappointment that this entire provoca.Y due to lack of good web design practices.

Julie Howell
Digital policy development manager
RNIB
RNIB Center for Web access www.rnib.org.uk/webaccesscentre

RNIB is running a series of seminars for web designers in October and noviembre.Para for more information, see your Web site.

This interview in Accessify Forum you can discuss.

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Do you need Internet Marketing?

Online Business

This article will explain why Internet marketing is necessary and why most Web sites can do their work without it.

Internet Marketing there is a common misconception among many people with websites is that as soon as you have a website people start looking and therefore will attract new this business is not true.


There are several ways in which to make people aware of your Internet Marketing website. The first and most obvious is through current articles. Of ones that supposedly already successfully do Internet marketing marketing (but then you probably not read this article) this will often include:

Business CardsComplement Slips internet marketing Media AdvertsInvoicesQuotesRecieptsStore FrontCompany vehicles

Obviously there are any many other ways, but you get the idea.Above represent an opportunity to address the market.To have a successful website you have to at every opportunity to let people know the address of your site.Once the website address is at the head of a person is a door to any amount of information you provide on the site, more information you might provide an advertisement ever, and is visible in leisure that person when you have time and desire to digest it.

Previous Internet Marketing methods are starting to attract visitors to the site.There are two problems.

First of all these methods are not generally attract businesses that don’t have won anyway, even if your site will improve the efficiency of communication with customers will be happier customers are not necessarily clients would not discovered him without the Web site.

Secondly, people are not as good as computers to remember things.And you only need aInternet Marketing  Web site address shall be indicated with a wrong not to find the sitio.Si person character remebered the direction at all.

There is a better manera.Esto should not be considered as an alternative to the previous methods, but as a complement to them.

When people are looking for a company to offer a product or service that increasingly to the Internet to find products or services on the Internet most popular method encontrarlo.El is through a search engine when someone writes the name of a product or service that is provided in a search engine is an ideal opportunity for you attract them as a customer.

They are interested in the product or service that you provide at this momento.No are in the middle of something else, or frame of mind who do not want to be bothered by your anuncio.están willing to learn and possibly purchase your product or service immediately.

Internet marketing is to make sure when someone searches for a product or service you provide .This is is accomplished through search or cost-per-click Engine Tuning.

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Author: Nigel Peck


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Google Dance


The name “Google Dance” is often used to describe the index update of the Google search engine. Google’s index update occurs on average once per month. It can be identified by significant movement in search results and especially by Google’s cache of all indexed pages reflecting the status of Google’s last spidering. But the update does not proceed as a switch from one index to another at one point in time. In fact, it takes several days to complete the index update. During this period, the old and the new index alternate on www.google.com. At an early stage, the results from the new index occur sporadically. But later on, they appear more frequently. Google dances.


The start dates of previous Google Dances have been compiled by WebmasterWorld’s administrator Brett Tabke. The reasons for the Google Dance shall be presented here.

Technical level: Expert || Date: 9th December 2002 || Author: Markus Sobek

MIS Editor: Thanks to dance.efactory.de and Markus Sobek for allowing us to reproduce this article. PageRank and Google are trademarks of Google Inc., Mountain View CA, USA. PageRank is protected by US Patent 6,285,999.

The Google search engine pulls its results from more than 10,000 servers which are simple Linux PCs that are used by Google for reasons of cost. Naturally, an index update cannot be proceeded on all those servers at the same time. One server after the other has to be updated with the new index.

Many webmasters think that, during the Google Dance, Google is in some way able to control if a server with the new index or a server with an old index responds to a search query. But, since Google’s index is inverse, this would be very complicated. As we will show below, there is no such control within the system. In fact, the reason for the Google Dance is Google’s way of using the Domain Name System (DNS).

Not only Google’s index is spread over more than 10,000 servers, but also these servers are, as of now, placed in seven different data centers. These data centers are mainly located in the US (i.e. Santa Clara, California and Herndon, Virginia), indeed, in June 2002 Google’s first European data center in Zurich, Switzerland went online. Very likely, there are more data centers to come, which will perhaps be spread over the whole world.

In order to direct traffic to all these data centers, Google could thoeretically record all queries centrally and then send them to the data centers. But this would obviously be inefficient. In fact, each data center has its own IP address (numerical address on the internet) and the way these IP addresses are accessed is managed by the Domain Name System.

Basically, the DNS works like this: On the Internet, data transfers always take place in-between IP addresses. The information about which domain resolves to which IP address is provided by the name servers of the DNS. When a user enters a domain into his browser, a locally configured name server gets him the IP address for that domain by contacting the name server which is responsible for that domain. (The DNS is structured hierarchically. Illustrating the whole process would go beyond the scope of this paper.) The IP address is then cached by the name server, so that it is not necessary to contact the responsible name server each time a connection is built up to a domain.

The records for a domain at the responsible name server constitute for how long the record may be cached by a caching name server. This is the Time To Live (TTL) of a domain. As soon as the TTL expires, the caching name server has to fetch the record for a domain again from the responsible name server. Quite often, the TTL is set to one or more days. In contrast, the Time To Live of the domain www.google.com is only five minutes. So, a name server may only cache Google’s IP address for five minutes and has then to look up the IP address again.

Each time, Google’s name server is contacted, it sends back the IP address of only one data center. In this way, Google queries are always directed to different data centers by changing DNS records. On the one hand, the DNS records may be based on the load of the single data centers. In this way, Google would conduct a simple form of load balancing by its use of the DNS. On the other hand, the geographical location of a caching name server may influence how often it receives the single data centers’ IP addresses. So, the distance for data transmissions can be reduced. In order to show the DNS records of the domain www.google.com, we present them here by the example of one caching name server.

How data centers, DNS and Google Dance are related, is easily answered. During the Google Dance, the data centers do not receive the new index at the same time. In fact, the new index is transferred to one data center after the other. When a user queries Google during the Google Dance, he may get the results from a data center which still has the old index at one point im time and from a data center which has the new index a few minutes later. From the users perspective, the index update took place within some minutes. But of course, this procedure may reverse, so that Google switches seemingly between the old and the new index.

The progression of a Google Dance could basically be watched by querying the IP addresses of Google’s data centers. But queries on the IP addresses are normally redirected to www.google.com. However, Google has domains which resolve to the single data centers’ IP addresses. These domains as well as their IP addresses are shown in the following list.

Domain IP Address
www-ex.google.com 216.239.33.100
www-sj.google.com 216.239.35.100
www-va.google.com 216.239.37.100
www-dc.google.com 216.239.39.100
www-ab.google.com 216.239.51.100
www-in.google.com 216.239.53.100
www-zu.google.com 216.239.55.100

For every domain www-xx.google.com, there is an additional domain www-xx2.google.com. The IP address of such a domain ends on .101 instead of .100. These pairs of domains and IP addresses belong to the same data center and, hence, the same index is searched by queries on them.

Note: Searches at www-sj and www-zu are currently redirected to other data centers. Since results for searches at their IP addresses fluctuate heavily during a Google Dance, also these searches seem to be internally routed to other data centers. As we can see from our statistics for Google’s DNS records, there are currently no searches at www.google.com directed to www-sj or www-zu. So, we can assume that the two data centers are offline.

Those that keep an eye on Google’s index updates often think that the Google Dance is over, when they see the new index at www.google.com or when they don’t see the old index at www.google.com for some time. In fact, the update is not finished until all the domains listed above provide results from the new index.

The index updates at the single data centers seem to happen at one point in time. As soon as one data center shows results from the new index, it won’t switch back to the old index. This happens most likely because the index is redundant at each data center and at first, only one part of the servers (eventually half of them) is updated. During this period, only the other half of the servers is active and provides search results. As soon as the update of the first half of servers is finished, they become active and provide search results while the other half receives the new index. Thus, from the user’s perspective, the update of one data centers happens at one point in time.

Finally, it shall be noted that the access to the single data centers is generally controlled by the DNS only, but sometimes queries are redirected. However, this is easy to detect: When for a query at one of the domains listed above, the links to Google’s cache do not comply with the IP address that belongs to the domain, then the query is redirected. If this happens, Google inhibits – for whatever reason – the access to one data center.

The begin of a Google Dance can always be watched at the test domains www2.google.com and www3.google.com. Those domains normally have stable DNS records which make the domains resolve to only one (often the same) IP address. Before the Google Dance begins, at least one of the test domains is assigned the IP address of the data center that receives the new index first.

Building up a completely new index once per month can cause quite some trouble. After all, Google has to spider some billion documents an then to process many TeraBytes of data. Therefore, testing the new index is inevitable. Of course, the folks at Google don’t need the test domains themselves. Most certainly, they have many options to check a new index internally, but they do not have a lot of time to conduct the tests.

So, the reason for having www2 and www3 is rather to show the new index to webmasters which are interested in their upcoming rankings. Many of these webmasters discuss the new index at the Google forums out on the web. These discussions can be observed by Google employees now being paid via direct deposit. At that time, the general public cannot see the new index yet, because the DNS records for www.google.com normally do not point to the IP address of the data center that is updated first when the update begins.

As soon as Google’s test community of forums members does not find any severe malfunctions caused by the new index, Google’s DNS records are ready to make www.google.com resolve to the data center that is updated first. This is the time when the Google Dance begins. But if severe malfunctions become obvious during this test phase, there is still the possibility to cancel the update at the other data centers. The domain www.google.com would not resolve to the data center which has the flawed index and the general public could not take any notice about it. In this case, the index could be rebuilt or the web could be spidered again.

So, the search results which are to be seen on www2.google.com and www3.google.com will always appear on www.google.com later on, as long as there is a regular index update. However, there may be minor fluctuations. On the one hand, the index at one data center never absolutely equals the index at another data center. We can easily check this by watching the number of results for the same query at the data center domains listed above, which often differ from each other. On the other hand, it is often assumed that the iterative PageRank calculation is not finished yet, when the Google Dance begins so that preliminary values exert influence on rankings at that point in time.

Most webmasters are interested in ranking changes for their website during the Google Dance. But, besides that, many also want to know about their new PageRank values. Normally, the Google Toolbar fetches the PageRank values from the data center that is specified by its IP address in the actual DNS record for www.google.com. Hence, when the Google Dance begins, the Toolbar usually displays the old PageRank values.

Google submits PageRank values in simple text files to the Toolbar. In former times, this happened via XML. The switch to text files occured in August 2002. The PageRank files can be requested directly from the domain www.google.com. Basically, the URLs for those files look like follows (without line breaks):

http://www.google.com/search?
client=navclient-auto&
ch=0123456789&
features=Rank&
q=info:http://www.domain.com/

There is only one line of text in the PageRank files. The last cipher in this line is PageRank.

The parameters incorporated in the above shown URL are inevitable for the display of the PageRank files in a browser. The value “navclient-auto” for the parameter “client” identifies the Toolbar. Via the parameter “q” the URL is submitted. The value “Rank” for the parameter “features” determines that the PageRank files are requested. If it is omitted, Google’s servers still transmit XML files. The parameter “ch” transfers a checksum for the URL to Google, whereby this checksum can only change when the Toolbar version is updated by Google.

The PageRank files that are requested by the Google Toolbar are cached by the Internet Explorer. So, their URLs and the checksums can simply been found out by having a look at the folder Temporary Internet Files. Knowing the checksums of your URLs, you can view the PageRank files in your browser. Since the PageRank files are kept in the browser cache and, thus, are clearly visible, and as long as requests are not automated, watching the PageRank files in a browser should not be a violation of Google’s Terms of Service. However, you should be cautious. The Toolbar submits its own User-Agent to Google. It is:

Mozilla/4.0 (compatible; GoogleToolbar 1.1.60-deleon; OS SE 4.10)

1.1.60-deleon is a Toolbar version which may of course change. OS is the operating system that you have installed. So, Google is able to identify requests by browsers, if they do not go out via a proxy and if the User-Agent is not modified accordingly.

Now, let’s see how we can get the new PageRank values. Taking a look at IE’s cache, you will notice that the PageRank files are not requested from the domain www.google.com but from IP addresses like 216.239.33.102. Additionally, the PageRank files’ URLs often contain a parameter “failedip” that is set to values like “216.239.35.102;1111” (Its function is not absolutely clear). However, it is pretty easy to get the new PageRank values. Simply modify the IP addresses in the URL so that the request goes to one of the data centers that already has the new index. The necessary information is given above.

Copyright for this article belongs to dance.efactory.de.

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Understanding of Relational Databases

This is a free sample chapter from Beginning PHP 4 Databases published by Wrox Press.

As we have briefly seen in the previous chapter, there are many possible ways to structure data, such as trees, lists, and objects. In relational databases, data is structured as relations. Relations are expressed as sets of tuples, which are implemented in the form of tables. Conceptually, tables are easy to grasp, since it is a form that is familiar to most people.Anyone who has read to spreadsheet, a train timetable, or even a television guide is already familiar with the organization of data into columns and rows.In this chapter, we will lay out the basic concepts of relational databases and describes the process of organizing data in a relational manner.The topics covered in this chapter are:

Schema normalizationThe process by which redundancy and inconsistency are eliminated from the database Keys Fields or combinations of fields that are used to identify records Referential integrity Al state of consistency for database schemata Entity relationship diagrams Models used to design databases

Tables represent entities, which are unique items like people, objects, and relationships about which we wish to store data. Each row represents an instance of the entity.In the above example, each row represents an instance of one donor. In relational database terminology, an instance is known as a record, but the row or tuple terms are also used.

Each column represents an attribute of the entity, or something about the entity. In this case, each column represents a donation made by the donor, listing the amount of the donation and the project to which the money is donated. In relational database terminology, an attribute is known as a field, but the term column is also very common. Adding or removing columns would change both the data stored in the table and the actual structure of the table, whereas adding or removing rows would only change data stored in the table.In other words, removing a column removes information about entities whereas removing a row only removes one instance of an entity but no information about them in general.

As we shall see in the next chapter, each field in a table is assigned a data type. The type indicates what sort of data will be stored in that field: text data, integer data, boolean (true or false) data, and so on. The assigned type then applies to that field’s value for every record in the table.

We create databases because we need to store information. For the information in the database to be useful, we need to be able to perform certain operations on it. These operations fall broadly into two categories: reading the data, and changing the data. Whether one wishes to read a record, update it, or delete it, one first needs to identify the record in a way that distinguishes it from the other records in the table.

This is where keys come in.A key is a field or a combination of fields whose value identifies a record for a given purpose. One type of key is a unique key, which can be used to identify a single record. For example, every book has a unique ISBN (International Standard Book Number) that marks the book unmistakably. If a table of information about books includes an ISBN field, then that field can serve as a unique key.

A table might have more than one unique key. Suppose that each book in our table also has a unique product ID.While there is no problem with the existence of more than one unique key, it is considered desirable to have one that stands out as the primary key – the key that is considered the foremost means of identifying a record. In this case each of the unique keys is known as a candidate key, since each has the possibility of serving as the primary key. It is then up to the database designer to designate the primary key from among the candidate keys.

In our example from the previous section, the Donor field is a candidate key, if we accept (for now) that each donor is unique within the table. We shall revisit the topic of keys later in this chapter.

At first glance, a simple table such as the one shown in the chapter seems to meet all of our needs for storing data.When designing and filling the table, we may add as many fields and records as we like to accommodate large amounts of data. But after some examination, we are likely to encounter quite a few failings with our table. What if a donor makes more than three donations? We can add more fields to the table, of course, but to change the structure of a database eleven it is in use is extremely inconvenient. Also it is difficult to know in advance how many donations would be enough. What if one donor makes dozens of donations?

What if we wish to store more information about a project, such as a description? Do you Or even more information about a donation, such as the date?Again, while it is conceivable that additional columns could address this issue, such a solution would be awkward and wasteful.If columns named DonationDate1 and DonationDate2 are added, the same uncertainty over the appropriate number of columns exists.Adding a description after every project name produces a lot of redundant data, since each project appears in the table multiple times.Every time a new donation is made, the description of the project would have to be repeated.Such redundancy is very inefficient as seen in the following table:

DonorAmount1Project1Description1Amount2Project2Description2Powering schools with solar panelsCleaning up litter and pollutants from Pear CreekPurchasing and preserving land in the Danube watershed

The underlying problem is that a table is two-dimensional.It consists of columns and rows.Real-world data is usually multi-dimensional.We wish to store not only the data relevant to the donors and donations, but also data that relates to details in the table, such as additional information about the projects.There is a solution to our problem.Relational databases allow us to create multiple tables of related data.The database designer uses the relationships between these tables to represent multi-dimensional data.This is also why they are called relational databases.Let’s now look at the process of normalization in relational databases.

> Normalization

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Useful tips for Web designers

Web Designing is as easy as 1-2-3, claim some of the software tools on the market that “generate” your pages for you. Unfortunately, many web designers today have fallen prey to this marketing gimmick – and the results are obvious. Every now and then, one comes across a website that looks good with a particular browser and a particular screen-resolution; but view it with a different browser, and you can’t even read the plain text on the page. Worse still, given the number of operating systems that are used by netizens worldwide, these pages will never be seen properly by more than a half of the intended surfers.

Technical level: Intermediate || Date: 16th December 2002 || Author: Manas Tungare

Now let’s assume that this web page belongs to a site that sells stuff online. The very fact that half the users cannot even see the page, translates into losses worth half the amount straightaway (perhaps, even more!) I guess that makes a good case for the raison d’?tre of this article! Web Designing is, in my opinion, a cocktail of creative skills & technical prowess – and one is no less important than the other.

In the following lines, I have jotted down a few points that I noticed during my online journeys, important from the point of view of web designers. Some of them may be taken with a pinch of salt; for it is not possible to please everyone everytime. But most of them are simple enough to be used as a rule of thumb.

A picture, they say, is worth a thousand words. A picture file, alas, is also almost as big. Images, no doubt, enhance the look of a page, but it is not advisable to go overboard in stuffing your page with a truckload of images. Most net-surfers use a dial-up connection, and the average time to load a page should be no longer than 5 seconds. If it’s longer, the surfer will most probably click away elsewhere. So, within this time, all the images on a page must be loaded as well. So, as a rough yardstick, keep the aggregate page size less than 30k.

Another important point to note is that each file on the page requires a separate HTTP request to the server. So a lot of small images – even if they do not add up to a lot in terms of bytes – will slow down the loading a lot.

Even when you must use images for navigation, please give a second thought to the users who will not be seeing those jazzy, fantastic & truly amazing buttons that you spent hours to design. Yes, I’m talking of the ALT text attribute of the IMG tag. Do not forget to provide an Alternate Text for each image that you use for navigation. (It may be left blank for certain images that are purely for aesthetic reasons, but let that be an exception, rather than the rule.) Though not obviously apparent, ALT text can help such users immensely.

Modern browsers offer users a choice to turn off images. This gives an idea of how troublesome the unwanted images could be.

A couple of more attributes that make your pages load faster are the HEIGHT and WIDTH attributes. Without these, the browser must wait for the image to download since it cannot know how much space to leave for them!

Navigability & functionality come before artistic excellence. It is no use making your site a masterpiece of art if users cannot navigate around it – even after they reach the main page, they have no clue as to how to go where they want to go.

Especially common, is a kind of navigation that some people call Mystery Meat Navigation. That means, that unless your mouse moves over an image, you have no idea where that link might take you. Only when the mouse hovers do you see the actual link. This is cumbersome because users need to move their mouse all over the place to find out which part is a link and which is not.

Follow the K.I.S.S. principle: Keep it simple, stupid!

Next is a very important practical suggestion: whenever your whole page is within a TABLE, the page cannot render (i.e., the page does not show on the screen) unless the entire table is downloaded. You might have noticed this on several websites, when there is no activity for a long time, and suddenly the entire page is visible. Hence, to avoid such a situation, what you should do is this: Split the table up into two tables one below the other, and let the top one be a short table that displays just the page header and a few navigation links. So now, immediately upon downloading this part of the page, users can see the page header – and this prepares them for the long wait ahead, as well as keeps them from leaving your site to go to other sites, in case of a slow connection.

The ongoing browser wars have left only one casualty – the user. As a word of caution, stay away from all browser-specific functions. Because if a certain feature is supported by one browser, it will most definitely not be supported by another. Where you must use such features, it should not hamper the display of the page in the other browser which does not support such functionality. In other words, your page should degrade gracefully.

Creating a new browser window should be the authority of the user only. Do not try to popup new windows to clutter the user’s screen. All links must open in the same window by default. An exception, however, may be made for pages containing a links list. It is convenient in such cases to open links in another window, so that the user can come back to the links page easily. Even in such cases, it is advisable to give the user a prior note that links would open in a new window.

Keep in mind the fonts-challenged users too. The ultra-jazzy “Cloister Black MT Light” font that looks so amazing on your machine may well be degraded into plain old Times New Roman on your user’s machine. The reason? He/she does not have the font installed on his/her machine – and one thing’s obvious – there’s nothing you can do about the situation, sitting halfway across the globe from them.

Stay clear of out-of-the-way hard-to-find fonts. Use plain vanilla fonts like Arial, Verdana, Tahoma, and Courier. If need be, make your jazzy fonts into an image and put that on the page. (and while you’re there, do not forget Tip #1.)

A new design trick that is increasingly being used on the web has caught my fancy: It is a very functional navigation bar that guides you across all possible paths within the site. It looks something like this:

Home > Section > Subsection > Page

What better than to give your users a handy way of visiting just about any other page on your own site, and informing them where they are!

Another new trend on the web is not all that inviting – various vendors come up with “revolutionary plug-ins” and undoubtedly, most amateur web designers jump up to spruce up their pages using them. The reality is that most people won’t have them installed, and wouldn’t care about it anyway. Come to think of it, have you seen plug-ins on any of the most popular sites, including Yahoo.com, Amazon.com or Google.com? It’s simply not the best thing to do. Mention must be made here of Macromedia’s Shockwave Flash plug-in, which has now made its way onto most computers today, and thus presents no harm in using vector animation on your site.

Java is yet another often-misused technology on webpages. Use Java as a utilitarian programming language, not as a graphics front-end for your photos/images. There are various things you can do with Java; that does not mean you should do all of them. Java applets are known to run slower, so users experience a certain sluggishness in performance. And worse still, Java has been known to crash certain browsers. This is not something everyone likes, especially if it is done for the sole purpose of showing a set of images in a slideshow!

The moral: Use it, but with discretion.

Never underestimate the importance of those META tags. They can make all the difference between your users coming to your site and going to your competitor’s – just because they couldn’t find yours. Search Engines heavily rely upon the Keywords & Description Meta tags to populate their search database. And once again, use discretion in writing these. Including a huge number of keywords for the same page can spell trouble. The description should be a small, meaningful summary of the whole page that makes sense even when seen out-of-context of the webpage itself, say, in a listing of search engine results.

And the final point that summarizes all the points so forth: Write for all browsers, all resolutions, and all color-depths. If you show people pages that look best with their own browser and their own resolution, that makes them feel “at home”, and you get a better response. Compare this with a website that proclaims “Viewed best with Browser X at a resolution of 1024×768.” I’ll give you a choice between two options when you see such a page: download the suggested browser (which might well be over 50 Megs), then go get a new monitor that supports the high-resolution, and then adjust your screen setting so you get the perfect picture. Or simply click away to another site. Which do you prefer?

The web waits for no one. And furthermore, the user is king. Try your best to keep the user happy. And to keep all users happy. For, a good website is like a good storefront – it can mean all the difference between a casual surfer and a serious customer.

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This article is Copyright © 2000, Manas Tungare. Permission is hereby granted to reproduce this article with prior intimation to the author, and provided this notice is kept intact.

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Using relative font sizes

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skip to navigation Technical level: Advanced || Date: 27th January 2003 || Author: Mark Pilgrim

This article is copyright 2002 by Mark Pilgrim, and is republished here under the terms of the GNU Free Documentation License. It is part of a larger free book, which you can read at http://diveintoaccessibility.org/.

Web sites, with few exceptions, center around words. News, opinions, thoughts, ideas, stories, original writing, e-commerce: all words. Visual design and images are important, to be sure, but if people can’t read your words, what’s the point?

In the fall of 2000, Jeffrey Zeldman famously said that relative font sizing was impossible (“pixels, baby… or nothing”) because of an overwhelming variety of browser bugs, starting with Netscape 4 and ending in the most modern browsers. Since then, Netscape 4 still hasn’t gotten any better, and it still hasn’t gone away, but at least we’ve all learned a thing or two about taming the browsers and making relative font sizing a reality. (Zeldman too; his recently reincarnated Web Standards Project uses the technique described below.)

Use relative font sizes in browsers that can handle them, and absolute font sizes in Netscape 4, which does not reliably support relative font sizes. You can do this even if you don’t use multiple stylesheets. In a minute, I’ll give copy-and-paste solutions for the default Movable Type template and all default Radio themes. And a lengthy explanation of the technique itself to help you implement it in other templates.

Lillian benefits. Lillian has difficulty seeing web pages clearly, due to nothing more than old age. Like 80% of the Internet population, she uses Internet Explorer for Windows, which does not support resizing text unless the web designer exclusively specifies relative font sizes. Lillian has changed the default text size in her browser (under the “View” menu, “Text Size”), but it doesn’t do any good on sites that use absolute font sizes. This includes virtually every weblog template in existence. For example, this is what the default Movable Type template looks like to Lillian:

Text that is not readable because it is small and fuzzy as seen by someone with bad vision.

If the template used relative font sizes, it would look exactly the same to the majority of readers who don’t need (or care) to change their text size. But this is what it would look like to Lillian:

Text that is fuzzy but readable as seen by someone with bad vision.

Again: if people can’t read your words, what’s the point?

In your Home Page Template, look in your