There are two major types of color blindness. The most prevalent causes are confusion between red and green. This type affects approximately eight to ten percent of the male population. In another type, an additional one to two Percent of men suffer from a deficiency in perceiving blue/yellow differences. Less than one percent of women suffer from any form of color blindness. To understand color blindness better, it is helpful to be familiar with the ways in which colors differ from each other. One standard way to discuss color is to divide it into hue, saturation and brightness (HSB).

Hue

Hue is the element that distinguishes one color of the rainbow from another. It is the quality that infuses an object with “orangeness” or “redness” or “blueness”. In terms of people with color blindness, red and green hues are not differentiated as well as they should be.

Saturation

Saturation, the second element of the HSB color model, is the “pureness” of the color. High saturation equates to intense, “colorful” color. A color is desaturated by adding varying amounts of the its opposite or complementary color. Adding some blue-green desaturates Red. As colors become more desaturated, they tend toward a neutral grey. Less saturated colors are harder for the colorblind to distinguish.

Brightness

The third element, brightness, is sometimes called “lightness” or “value.” (The highest value equals white; the lowest value equals black.) Changing the brightness or value of a color is accomplished by diluting it with white, which makes the color become lighter or pastel, or with black, which makes the color become darker or more subdued. Colors with similar brightness are harder for the color-blind to distinguish.

If the designer wishes the interface to be equally effective to individuals both with and without color blindness, color-cueing should take into account potential red/green and blue/yellow confusion.

What can be done to avoid confusion?

Always provide an additional cue; don’t rely on color alone. For example, the standard default web browser of a link is underlined blue lettering. Interestingly, this particular color coding would stand up quite well, even without the additional cue of the underline, since blue is the universally recognizable color.

A second way to counteract color deficiency confusions is to make sure that colors have a high degree of contrast with each other. Color should differ strongly in brightness. A very light green and a very dark red will be easier to distinguish than a red and green that are similar in brightness. Remember that the more similar two colors are in brightness or in saturation, the harder they will be to distinguish.

In general, when colors need to be distinct and recognizably different, select the light colors from orange, yellow, green or blue-green; select the darker colors from blue, violet, purple or red. (The colorblind already see blue, violet, purple and red as darker than normal.) Also, don’t pair colors similar in hue, in saturation, or in brightness.

Related Links

http://www.lighthouse.org/accessibility/effective-color-contrast/

There is no set of rules that guarantees a successful no search results implementation. However, by studying various search UI implementations, I’ve come up with three useful design directions:

1. Don’t be afraid to say I did not understand. Clearly indicate there are no search results, so the customer can recover.

2. Focus on providing a way out. Make sure every control on the page does something productive to help resolve the no search results condition.

3. Focus on the customer’s goal. Provide the most relevant recovery content first, while staying as close as possible to the customer’s original intent.

Removing some of a user’s original keywords is just one in long list of effective content strategies. Here are some useful ideas for content strategies, in order of their relevance to the user’s original query:

1. substituting a user’s original keywords with different keywords from a controlled vocabulary
2. removing some of a user’s original keywords, or making partial matches
3. matching categories or aspects
4. top searches, featured results, or most popular results
5. third-party resources and ads

Lower literacy is different than illiteracy: people with lower literacy can read, but they have difficulties doing so.

They must read word for word and often spend considerable time trying to understand multi-syllabic words.

They “plow” the text, line by line. This gives them a narrow field of view and they therefore miss objects outside the main flow of the text they’re reading.

They don’t scan text. As a result, for example, they can’t quickly glance at a list of navigation options to select the one they want. Their only other choice is to completely skip over large amounts of information.

Lower-literacy users tend to satisfice – accept something as “good enough” — based on very little information because digging deeper requires too much reading, which is both challenging and time consuming. As soon as text becomes too dense, lower-literacy users start skipping, usually looking for the next link. In doing so, they often overlook important information.

In addition, having to scroll breaks lower-literacy users’ visual concentration because they can’t use scanning to find the place they left off.

Finally, search creates problems for lower-literacy users for two reasons. First, they often have difficulty spelling the query terms. Second, they have difficulty processing search results, which typically show weird, out-of-context snippets of text. As a result, lower-literacy users often simply pick the first hit on the list, even if it’s not the most appropriate for their needs.

Improving Usability for Lower-Literacy Users

The main and most obvious advice is to simplify the text. 

Prioritize information. Place the main point at the very top of the page, where even readers who typically give up after a few lines will see it. Place any other important information above the fold, to minimize the risk of users losing their place after scrolling. This is always good practice; even the most skilled readers will leave a page if the first few paragraphs don’t seem valuable. It’s even better to avoid scrolling all together (which also helps teenagers) unless eliminating it requires you to chop content into unnaturally short sections, which can be even more confusing.

Avoid text that moves or changes, such as animations and fly-out menus. Static text is easier to read. This guideline also helps international users (who might need to look up words in a dictionary) and users with motor skills impairments (who have difficulty catching things that move).

Streamline the page design. Place important content in a single main column, so users don’t have to scan the page and pick out design elements in a two-dimensional layout. This guideline also helps low-vision users and users of handheld devices (such as smartphones), which narrow the field of view.

Simplify navigation by placing the main choices in a linear menu. This helps users clearly understand the next place to go, without requiring them to scan the page for options.

Optimize search. Make your search tolerant of misspellings (which also helps seniors, who are particularly prone to making typos). Ideally, a user’s first search hit should answer the query, and all hits should provide short, easy-to-read summaries.

• The frequency with which the problem occurs: Is it common or rare?
• The impact of the problem if it occurs: Will it be easy or difficult for the users to overcome?
• The persistence of the problem: Is it a one-time problem that users can overcome once they know about it or will users repeatedly be bothered by the problem?

Finally, of course, one needs to assess the market impact of the problem since certain usability problems can have a devastating effect on the popularity of a product, even if they are “objectively” quite easy to overcome. Even though severity has several components, it is common to combine all aspects of severity in a single severity rating as an overall assessment of each usability problem in order to facilitate prioritizing and decision-making.The following 0 to 4 rating scale can be used to rate the severity of usability problems:

0 = I don’t agree that this is a usability problem at all 
1 = Cosmetic problem only: need not be fixed unless extra time is available on project 
2 = Minor usability problem: fixing this should be given low priority 
3 = Major usability problem: important to fix, so should be given high priority 
4 = Usability catastrophe: imperative to fix this before product can be released

• Heuristic evaluation is the most informal method and involves having usability specialists judge whether each dialogue element follows established usability principles (the “heuristics”).
• Heuristic estimation is a variant in which the inspectors are asked to estimate the relative usability of two (or more) designs in quantitative terms (typically expected user performance).
• Cognitive walkthrough uses a more explicitly detailed procedure to simulate a user’s problem-solving process at each step through the dialogue, checking if the simulated user’s goals and memory content can be assumed to lead to the next correct action.
• Pluralistic walkthrough uses group meetings where users, developers, and human factors people step through a scenario, discussing each dialogue element.
• Feature inspection lists sequences of features used to accomplish typical tasks, checks for long sequences, cumbersome steps, steps that would not be natural for users to try, and steps that require extensive knowledge/experience in order to assess a proposed feature set.
• Consistency inspection has designers who represent multiple other projects inspect an interface to see whether it does things in the same way as their own designs.
• Standards inspection has an expert on an interface standard inspect the interface for compliance.
• Formal usability inspection combines individual and group inspections in a six-step procedure with strictly defined roles to with elements of both heuristic evaluation and a simplified form of cognitive walkthroughs.

Heuristic evaluation, heuristic estimation, cognitive walkthrough, feature inspection, and standards inspection normally have the interface inspected by a single evaluator at a time (though heuristic evaluation is based on combining inspection reports from a set of independent evaluators to form the list of usability problems and heuristic estimation involves computing the mean of the individual estimates). In contrast, pluralistic walkthrough and consistency inspection are group inspection methods. Many usability inspection methods are so easy to apply that it is possible to have regular developers serve as evaluators, though better results are normally achieved when using usability specialists.

The following principles are fundamental to the design and implementation of effective interfaces, whether for traditional GUI environments or the web. Of late, many web applications have reflected a lack of understanding of many of these principles of interaction design, to their great detriment. Because an application or service appears on the web, the principles do not change. If anything, applying these principles become even more important.

• Anticipation
• Autonomy
• Color Blindness
• Consistency
• Defaults
• Efficiency of the User
• Explorable Interfaces
• Fitts’ Law
• Human Interface Objects
• Latency Reduction
• Learnability
• Metaphors, Use of
• Protect Users’ Work
• Readability
• Track State
• Visible Navigation

In general, heuristic evaluation is difficult for a single individual to do because one person will never be able to find all the usability problems in an interface. Luckily, experience from many different projects has shown that different people find different usability problems. Therefore, it is possible to improve the effectiveness of the method significantly by involving multiple evaluators.

My recommendation is normally to use three to five evaluators since one does not gain that much additional information by using larger numbers.

Heuristic evaluation is performed by having each individual evaluator inspect the interface alone. Only after all evaluations have been completed are the evaluators allowed to communicate and have their findings aggregated. This procedure is important in order to ensure independent and unbiased evaluations from each evaluator.

The output from using the heuristic evaluation method is a list of usability problems in the interface with references to those usability principles that were violated by the design in each case in the opinion of the evaluator. It is not sufficient for evaluators to simply say that they do not like something; they should explain why they do not like it with reference to the heuristics or to other usability results. The evaluators should try to be as specific as possible and should list each usability problem separately.

Heuristic evaluation does not provide a systematic way to generate fixes to the usability problems or a way to assess the probable quality of any redesigns. However, because heuristic evaluation aims at explaining each observed usability problem with reference to established usability principles, it will often be fairly easy to generate a revised design according to the guidelines provided by the violated principle for good interactive systems. Also, many usability problems have fairly obvious fixes as soon as they have been identified.

Differences with Formal Usability Testing

In a user test situation, the observer (normally called the “experimenter”) has the responsibility of interpreting the user’s actions in order to infer how these actions are related to the usability issues in the design of the interface. This makes it possible to conduct user testing even if the users do not know anything about user interface design. In contrast, the responsibility for analyzing the user interface is placed with the evaluator in a heuristic evaluation session, so a possible observer only needs to record the evaluator’s comments about the interface, but does not need to interpret the evaluator’s actions.

Two further differences between heuristic evaluation sessions and traditional user testing are the willingness of the observer to answer questions from the evaluators during the session and the extent to which the evaluators can be provided with hints on using the interface. For traditional user testing, one normally wants to discover the mistakes users make when using the interface; the experimenters are therefore reluctant to provide more help than absolutely necessary. Also, users are requested to discover the answers to their questions by using the system rather than by having them answered by the experimenter. For the heuristic evaluation of a domain-specific application, it would be unreasonable to refuse to answer the evaluators’ questions about the domain, especially if nondomain experts are serving as the evaluators. On the contrary, answering the evaluators’ questions will enable them to better assess the usability of the user interface with respect to the characteristics of the domain. Similarly, when evaluators have problems using the interface, they can be given hints on how to proceed in order not to waste precious evaluation time struggling with the mechanics of the interface. It is important to note, however, that the evaluators should not be given help until they are clearly in trouble and have commented on the usability problem in question.

Since the evaluators are not using the system as such (to perform a real task), it is possible to perform heuristic evaluation of user interfaces that exist on paper only and have not yet been implemented (Nielsen 1990). This makes heuristic evaluation suited for use early in the usability engineering lifecycle.

Independent research (Jeffries et al. 1991) has indeed confirmed that heuristic evaluation is a very efficient usability engineering method. One of the case studies found a benefit-cost ratio for a heuristic evaluation project of 48: The cost of using the method was about $10,500 and the expected benefits were about $500,000 (Nielsen 1994).

In principle, individual evaluators can perform a heuristic evaluation of a user interface on their own, but the experience from several projects indicates that fairly poor results are achieved when relying on single evaluators. It would seem reasonable to recommend the use of about five evaluators, but certainly at least three. The exact number of evaluators to use would depend on a cost-benefit analysis. More evaluators should obviously be used in cases where usability is critical or when large payoffs can be expected due to extensive or mission-critical use of a system.

Nielsen and Landauer (1993) present such a model based on the following prediction formula for the number of usability problems found in a heuristic evaluation:

ProblemsFound(i) = N(1 - (1-l)i )

where ProblemsFound(i) indicates the number of different usability problems found by aggregating reports from i independent evaluators, N indicates the total number of usability problems in the interface, and l indicates the proportion of all usability problems found by a single evaluator. In six case studies (Nielsen and Landauer 1993), the values of l ranged from 19 percent to 51 percent with a mean of 34 percent. The values of N ranged from 16 to 50 with a mean of 33. Using this formula results in curves very much like that shown in Figure 2, though the exact shape of the curve will vary with the values of the parameters N and l, which again will vary with the characteristics of the project.

What is a heuristic?

Molich and Nielsen (1990) wrote a paper that contains a set of heuristics still in popular use:

1. Use simple and natural dialogue.
2. Speak the user’s language.
3. Minimize the user’s memory load.
4. Be consistent.
5. Provide feedback.
6. Provide clearly marked exits.
7. Provide shortcuts.
8. Provides good error messages.
9. Prevent errors.
10. Provide help and documentation.

Nielsen (1994), after evaluating several sets of heuristics, concluded that a better set of heuristics may be:

1. Ensure good visibility of system status.
2. Have a good match between the system and the real world.
3. Ensure user control and freedom.
4. Use consistency and standards.
5. Design to prevent user errors.
6. Design to facilitate recognition rather than recall memory.
7. Provide for flexibility and efficiency of use.
8. Use aesthetic and minimalist design concepts.
9. Help users recognize, diagnose, and recover from errors.

Gerhardt-Powals (1996) proposed a set of research-based heuristics:

1. Automate unwanted workload:
   1. Free cognitive resources for high-level tasks.
   2. Eliminate mental calculations, estimations, comparisons, and unnecessary thinking.
2. Reduce uncertainty; display data in a manner that is clear and obvious.
3. Fuse data; reduce cognitive load by bringing together lower level data into a higher-level summation.
4. Present new information with meaningful aids to interpretation:
   1. Use a familiar framework, making it easier to absorb.
   2. Use everyday terms, metaphors, etc.
5. Use names that are conceptually related to function.
   1. Context-dependent.
   2. Attempt to improve recall and recognition.
6. Group data in consistently meaningful ways to decrease search time.
7. Limit data-driven tasks:
   1. Reduce the time spent assimilating raw data.
   2. Make appropriate use of color and graphics.
8. Include in the displays only that information needed by the user at a given time.
9. Provide multiple coding of data when appropriate.
10. Practice judicious redundancy.

Theoretically, the heuristics are related to criteria that, if improved, could make a positive difference in the product’s usability. Unfortunately, the “usability problems” identified in a heuristic evaluation differ substantially from those obtained in performance testing. Only the Gerhardt-Powals set of heuristics has been validated. If other sets of heuristics are used, designers should first ensure that the evaluation actually would lead to improved Web site performance or acceptance.

How does it differ from an expert review?

In an expert review, the heuristics are assumed to have been previously learned and internalized by the evaluators. That is to say, evaluators do not use a clear-cut set of heuristics. As a result, the expert review tends to be less formal, and usually there is no requirement to assign a specific heuristic to each potential problem.

What are the advantages of a heuristic review?

The method can provide some quick and relatively inexpensive feedback to designers. Feedback can be obtained early in the design process. Assigning the correct heuristic can help suggest the best corrective measures to designers.

What are the disadvantages of a heuristic review?

Using this type of evaluation to identify usability problems is very difficult, research shows that it may result in only a 50% hit rate, and a 20% miss rate.

Results are not based on observations of user behavior, and will result in suggesting changes to the Web site that are not required (about a 50% false positive rate).

If the wrong heuristics are assigned to potential problems, it will mislead designers into applying the wrong solutions to the problems.

While building web interfaces, we often build efficient and elegant ways to accomplish user experience goals, but many times our users do not use them. Most of the times it is not sufficient to just design the content or the web interface alone. We need to analyze the entire interaction pattern of users with the web to deliver better user experience. Figure 1 depicts how most users like to reach an online content; search being the most popular activity. In August 2007, 95% of the worldwide internet audience conducted 61 billion searches with an average of 80 searches per user in a month [14].

Figure 1. Users browsing pattern diagram.

With over 70% of site traffic [18] coming through search engines, searching online is the most popular activity [16]. Studies also show that people seem to value relevance over accuracy [10]. What seems evident from such online browsing behavior is that people pick the first link that gives them a scent of the value it is worth for, and not necessarily choose the one which might be the best for their needs. As search engines enable this access of content, we need to consider optimization for search engines as an integral part of the process of creating an application.

Section 2 of this paper establishes the model of prevalent web development life cycle and identifies the problem area. A brief discussion on the suggested solution establishes the importance of SEO in context of creating an application. Section 3 of the paper details of how to achieve optimization for search engines by categorizing activities based on the roles of the stakeholders involved. The discussed issues form basis for these stakeholders to account for various pitfalls which otherwise might prove to be major hurdles towards the end of a project.

2. WEB DEVELOPMENT LIFE CYCLE

2.1 What is current scenario?

As web upgraded to the era of 2.0, allowing users a smooth access to richer content, the design focus has shifted from delivering a ‘can do’ service, to delivering a ‘will do’ experience. The paradigm shift from designing for user needs to designing for user emotions calls for refining the design process too. We can categorize an iterative development lifecycle into three phases as illustrated in Figure 2 – gather insights from stakeholders; create application based on feasibility; and launch, and iterate the designs at every stage of the process.

Figure 2. A Typical Web Development Life Cycle.

2.2 What is the problem?

In the web development life cycle, the linear process to create an application is further classified into different stages of designing the web pages; developing the interfaces; and optimizing the entire application. Every stage has its own challenges and requirements and hence the roles of designers, developers, and optimization specialists are played by different individuals who often have limited visibility of each others domains. This often leads to more iterations and unwanted designs which delays the projects and affects the quality of user experience.

2.3 How to improve?

To avoid the above pitfalls, it is essential to bring more visibility for the designers and the developers on how to optimize their designs for function and performance. We recognize a need to account for intricate optimization issues by designers and developers at an early stage of the development life cycle. This helps retain the essence of the design throughout its life cycle and allows to retain the envisioned user experience. Since most users access content through search engines, we need to understand the needs of the search engine and how it enables access.

Figure 3. User Experience Design Process – A mechanism to account for optimization intricacies during early design stages to provide seamless user experience.

3. SEARCH ENGINE OPTIMIZATION

3.1 How Search Engines Work?

Today search engines like Google, Yahoo, MSN, Baidu and many others are virtual gateways of information. As of July 2008, Google is the most popular search engine globally with a share of 64.1% searches largely ahead of Yahoo at 14.6%, and an emerging Chinese engine Baidu at 12.9% [13].

Every search engine has its own algorithm for listing pages, but the overall behavior largely remains the same [23]. The web crawlers or spiders roam the entire web to create an index of the webpage content based on keywords. Though, keywords are a crucial success factor in SEO, but they alone are not sufficient to provide required visibility to the content. In order to achieve high Search Engine Ranking Position (SERP), the owner of the website needs to consider numerous parameters which play crucial role in deciding the rankings against a set of keywords.

3.2 What is Search Engine Optimization?

The content of your website is valuable only if it is relevant and reachable. Search Engine Optimization (SEO) is a set of methodologies aimed at making a site and its content highly relevant for both the search engine and the site users; and attempts to increase reach. There are two aspects to SEO that one needs to be aware of:

1. Understand needs of search engine, and make search engine understand what is to be delivered
2. Make the search engine believe that the site is genuine, and provides relevant and quality content

Most of the issues in the purview of the first aspect can be handled during design and development stages. Though the look-and-feel of the site and interactions influence user perception, there are a lot more aspects that contribute to the entire experience. While there are some definitive measures to account for the first aspect of SEO, the second aspect is a lot more subjective and highly competitive to achieve.

3.2 How to Optimize?

As a rule of thumb we must always design pages primarily for users, while aligning with search engine best practices. The focus should remain on improving content quality and avoiding grey tricks to generate organic traffic. Remember, often our pages do not get indexed by search engines the way it appears on the screen. Their indexing capabilities and hence visibility of our design, are limited by the intelligence of crawlers coming to the site. To achieve effective SEO we perform a host of interrelated activities which can broadly be classified into three categories [9] based on the roles we defined in Figure 3.

1. On-Page Optimization Issues: Apart from the usability and aesthetics aspects of page design, a designer can take care of the content quality, titles, images, links, and structure of a specific web page.
2. On-Site Optimization Issues: These issues have more to do with the site navigation structure and interaction of the pages within the site. Hence with some better understanding, a developer can account for these issues.
3. Off-Site Optimization Issues: These are highly subjective set of tactics adopted as per the business and competition situations and hence highly subjective by nature and require a dedicated specialist. They involve link building and strategy planning to determine site popularity apart from keyword research and web log analysis.

3.2.1 On-Page Optimization

• Content is king – No website can sustain without relevant and quality content. Each page should be fresh, and unique. Remember that spiders read like normal people (from left to right and from top to bottom for conventional languages like English). They feel that the most important information is located towards the top of the page [27]. Use text instead of images to display important names, content, or links [19].
• Links are queen – Use simple text links. This makes it easy for the crawlers to interpret the design and navigation as they do not recognize text contained in images. When linking internally, try to use keyword phrases as anchor text [24]. It is better to use phrases instead of single words as that helps both users and crawlers identify the context.
• Title defines content – Search engines use page title as a key indicator of the page’s content. They also show it as the first line in the search result pages. Hence, focus on a single topic per page and use that topic as the page title. When reading specific tags (title, h1, h2, etc.) search engines value words to the left more highly than words to the right. Keep page title under 66 characters, use ‘|’ symbol to insert different keyword phrases in the title [22].
• Images attract attention – Images are highly effective in drawing user attention, but increases the page size. Providing alt text with images increases the chances of people visiting the page as it allows search engines to display page in image search results [19].

3.2.2 On-Site Optimization

• Clear structure – Having simple and clear navigation structures ensures that crawlers have indexed all the pages of the website and makes it a lot easier for the users to browse. Make sure that there are no broken links in the website and each page is accessible by at least 1 static link [21].
• Follow W3C standards – Ensure that you have predefined standards for implementing various web technologies; this brings uniformity to the code and allows scalable development. Avoid tables deeper than 3 levels as some crawlers find it difficult to handle, use <div> layouts [24].
• Test with Lynx – Before inviting crawlers, test the web pages with unix based Lynx browser [19]. This gives an idea of how a page looks to a crawler.
• Nomenclature is fundamental – Having nomenclature guideline for filenames allows easy maintenance of various media types and helps better categorize in the long term [22].
• Light pages reward heavy – Try to keep page lean and mean, they are best optimized if they contain 350-550 words [25]. Also keep an upper limit of 800 characters on the keywords and around 150 characters for page description [25]. Keep in mind that some search engines may exclude a page if it is above 100Kb [25].
• Order meta-tags – Defining robots, content-type, title, description, keywords in respective order helps achieve better optimization performance [22].

3.2.3 Off-Site Optimization

The third category of issues is off-site optimization which is essential to ensure performance and visibility of the website. Involving an optimization specialist here is key to success of a website as they require dedicated efforts in terms of research and analysis both, within and outside the website.

• Robots helps – It is essential for any website to define robots.txt in the root folder as this file defines permission for a crawler and specifies which areas are to be indexed and which are private. The file also helps crawler to update its index regularly [21].
• Sitemap is essential – A sitemap defines structure of the website and helps crawlers verify structure of their indexed data. Divide the sitemap into multiple pages if it has more than 100 links [20].
• Give link Love, get link Love – Have more and more relevant sites link to yours. Link building is the most crucial aspect of optimizing for search engines as backlink determines popularity of a website [25]. Be cautious to build a quality network of websites around yours as that creates a lot of value and brings trust for users and search engines.
• Get keywords right – Think words that users think [19]. At times it helps to go for keyword phrases rather than single words. Choosing keywords is a huge exercise in itself and the final selection of keywords must align with the positioning strategy of the website.
• Analysis is key – Web logs can answer very interesting queries like who are your visitors, where are they coming from, what are they viewing on your site, what they like and what creates a problem. Analyzing site visitor patterns and comparing with market trends give a better understanding of the competition. Studying the competition regularly is the only way to beat them [25].
• Update regularly – As search engines keep evolving their algorithms, techniques that works today might not work tomorrow. The SEO landscape changes every 6-12 months [26], hence it is essential that the deployed techniques and strategies for a website also keeping evolving.

4. CONCLUSIONS

In this paper we briefed on why it is necessary to consider optimization as an integral part of the design process and what are the different aspects of optimization. The paper focuses on delivering a holistic user experience by reducing on unwanted design iterations. The discussed approach classifies SEO activities into three categories depending on the role of the stakeholders involved in creating the application. The tips provided in each section acts as a checklist to validate the designs and accomplish goals in a unified manner.

Acknowledgements: We thank our colleagues, seniors and the management at Human Factors International for their guidance and valuable feedback.

5. REFERENCES

[1] M Thomas, University of Hildesheim (2006), Conference on Hypertext and Hypermedia, Implementation and Evaluation of a Quality-Based Search Engine, pp. 73-84.

[2] X Bo, L Zhangxi (2006), ACM International Conference Proceeding Series, The Impact of Search Engine Optimization on Online Advertising Market, pp. 519-529.

[3] L Effie, R Virpi, P O S V Arnold, K Joke, H Marc (2008), CHI ’08 extended abstracts on Human factors in computing systems, Towards a shared definition of user experience.

[4] W Melius, M Mongezi (2004), SAICSIT ’04, Website navigation architectures and their effect on website visibility: a literature survey.

[5] S Craig, H Monika, M Hannes, M Michael (2005), Analysis of a Very Large Web Search Engine Query Log.

[6] Research-Based Web Design and Usability Guidelines, US Department of Health and Human Services, Chapter 2, Optimizing the User Experience.

[7] M L Alan, F Christos, Carnegie Mellon University, Identifying Web Browsing Trends and Patterns.

[8] M Aaron, President, Aaron Marcus and Associates, User-Experience Planning for Corporate Success.

[9] Australian Web Industry Association, seo – search engine optimization choosing the right provider.

[10] ZDNet, Research study data, http://news.zdnet.com/2100-3513_22-134493.html

[11] December Survey, http://www.pewinternet.org/trends/Internet_Activities_8.28.07.htm

[12] User Experience Definition, http://www.nngroup.com/about/userexperience.html

[13] Search Engine Market Share statistics, http://seekingalpha.com

[14] Global number of searches statistics, http://www.comscore.com/press/release.asp?press=1802

[15] Worldwide Internet Users time spent online, http://www.internetretailer.com

[16] Topmost online activity in US, http://www.itfacts.biz/category/www

[17] Traffic generated through Search Engines data, http://www.customermagnetism.com/

[18] IntactInfo for data on percentage of traffic coming to sites, http://www.intactinfo.com/

[19] Google Webmaster Guidelines, http://www.google.com/support/webmasters/bin

[20] Matt Cutts: Gadgets, Google, and SEO, http://www.mattcutts.com/blog/

[21] 55 Quick SEO Tips Even Your Mother Would Love, http://www.searchenginejournal.com

[22] Top 10 Search Engine Optimization Tips, http://www.top10seotips.com

[23] SEO – Search Engine Optimization Ranking Tips, http://www.submitawebsite.com/blog/

[24] 21 Essential SEO Tips & Techniques, http://searchengineland.com/070628-074149.php

[25] Building a search engine optimized Website, http://www.pandia.com/optimization/

[26] Search Engine Ranking Factors, http://www.seomoz.org/article/search-ranking-factors

[27] SEO and Your Website, http://www.digital-web.com/articles/seo_and_your_web_site/