Measuring the Usability of Your Web Site

Usability Index Checklist for Web Sites          
You can use this checklist to calculate the Usability Index of your Web site.          
Add or delete questions to match your requirements.          
Answer each checklist question with not applicable (N/A), yes, or no.          
If a category is missing (for example, no search tool) answer all questions in the category no.          
To determine the Usability Index count the number of yes answers compared with the total of the yes and no answers.          
With the Microsoft Excel 5.0 spreadsheet, use yes=1 and no=1 and the Usability Index is calculated for you.          
In the collaborative spirit of the Web, you can use this checklist for research; however,          
any commercial or business use requires prior permission from Keevil & Associates.          
Email any questions to Benjamin Keevil ( at          
This checklist was updated on September 13, 1998 from focus group feedback. To print, scale to 80%.          
Copyright (c) 1998 Keevil & Associates.          
Usability Index (calculated by Excel as a per cent)   76      
What is the name of the Web site?   Keevil & Associates      
What is the location (URL) of the Web site?      
What is the main purpose of the site?   Sell technical writing services      
(sell products or services, advertise jobs, conduct research, upgrade products, display information)          
What is the style of the site?   Simple technical      
How many users are there?   100      
When was the usability index measured?       May-98  
Checklist Questions          
Finding the Information N/A Yes No For more information...  
Contents list included?   1   Nielsen usability 1994  
Links in contents list correct?   1      
Site Map          
Site map included?   1   Nielsen usability 1994  
Links in site map correct?   1      
Headings labelled correctly?   1      
Two or three highest heading levels included?   1      
Capitalization, spelling, and punctuation correct?   1      
Acronyms avoided where possible?   1      
Headings (Choose one page at random)          
Headings brief and informative?   1      
Headings unique?   1      
Headings parallel?   1      
Headings stand out on the page?   1      
At least one heading on every page?   1      
Each heading accurately reflects tasks or information?   1      
Search tool included for sites with over 20 pages?     1    
Choose a topic at random -- can you find it?     1    
Index included?     1    
Entries in alphabetical order?     1    
Secondary and tertiary entries included?     1    
Up-to-date information          
Is the date of the last update indicated?   1      
Is there an automatic update notification mechanism?     1    
Is new information indicated?   1      
Finding an answer          
Choose a simple fact - can a user find it?   1      
Can the user find the answer in 10 minutes?   1      
Glossary included?     1    
Introductory statement correct?     1    
All specialized terms in site included?     1    
Terms not used in site eliminated?     1    
Format correct?     1    
Entries in alphabetical order?     1    
Lead-in wording of entries parallel and correct?     1    
Cross-referencing style correct?     1    
Acronyms treated correctly?     1    
Glossary proofread for spelling and punctuation?     1    
Definitions consistent with site definitions?     1    
Terms and definitions copied from organizations credited?     1    
Understanding the Information N/A Yes No    
Overview Page          
Is an "Overview" page or picture included?   1   Nielsen 1994  
Product description included?   1      
Description of relation to other products correct?   1      
Purpose and uses of product described?   1      
About This Site Topic (for 50-page sites)          
For 50-page sites, "About This Site" topic included?   1      
Sentence describing the site included?   1      
Sentence describing the product or service included?   1      
Topic "Organization of this site" included or implied?   1      
Topic "How to use this site" included?   1      
Topic "Software Release" included for software products? 1        
Topic "Who should read this site" included?   1      
Figure "Product Documentation Map" included? 1        
Topic "Related Publications" included? 1        
Topic "Prequisites and Corequisites" included? 1        
Topic "Conventions in This site" included? 1        
Topic "Getting Help" included?   1      
Organization of the Site          
Does every major topic have an "Introduction".   1      
"Introduction" part informative?   1      
Is the "inverted information pyramid" used?   1  
Organization conforms to style guidelines?   1      
Heading levels appropriate to level of detail?   1      
Headings task-based?   1      
Structure of lists parallel?   1      
Structure of procedures parallel?   1      
Structure of examples parallel?   1      
Each paragraph has main idea, described in topic sentence?   1      
Presentation moves from general to specific?   1      
Presentation moves from simple to complex?   1      
Information complete?   1      
Information limited to appropriate and necessary topics?   1      
Information in correct sequence?   1      
Procedures task oriented?   1      
Summary included and accurate?   1      
Style (Choose five pages at random)          
Style conforms to desired style?   1      
Editorial comments added or otherwise resolved?   1      
Active and passive voices used appropriately?   1      
Second person used appropriately?   1      
Present tense predominates?   1      
Reading level acceptable?   1      
One-sentence paragraphs used sparingly?   1      
Sentences simple but not terse?   1      
Latin words and abbreviations eliminated where possible?   1      
Transitions between topics smooth?   1      
Instructions in imperative mood?   1      
Positive expressions and expressions predominate?   1      
Abbreviations, acronyms, and symbols used sparingly?   1      
Abbreviations and acronyms in prescribed style?   1      
Imprecise (vague) words replaced with precise ones?   1      
Jargon avoided?   1      
Redundant and extraneous words removed?   1      
Coining of verbs, adjectives, and nouns avoided?   1      
Noun strings limited to maximum of three words?   1      
Examples included? 1        
Examples relate well to tasks? 1        
Examples tested and approved? 1        
Complexity of examples appropriate for audience? 1        
Figures consistent in font, layout, and style? 1        
Figures flow in an obvious manner? 1        
Figures easily interpreted? 1        
Figures suit information presented? 1        
Figures useful? 1        
Figures sufficient in number? 1        
Figures appropriately titled and numbered? 1        
Each figure title unique? 1        
Figures referenced in preceding text? 1        
Titles, callouts, and annotations informative? 1        
Figures correctly integrated with the text? 1        
List of Abbreviations          
List of abbreviations included?     1    
Entries in alphabetical order?     1    
Style correct, concise, and readable?     1    
Approved terminology used?   1      
Terminology based on standards?   1      
Sources of specialized terminology listed in bibliography?   1      
General terms used as defined in Webster's dictionary?   1      
Naming conventions applied correctly and consistently?   1      
Highlighting conventions consistent and correct?   1      
New terms highlighted and defined when first used?   1      
Synonyms avoided after meaning of terms established?   1      
Meaning of each term consistent throughout each site?     1    
Meaning of each term consistent throughout set of sites?   1      
First occurrences of abbreviations follow spelled-out words?   1      
Level of technical terms appropriate to audience?   1      
Depreciated, restricted, and forbidden words avoided?   1      
Difficult-to-translate words avoided?   1      
Supporting User Tasks N/A Yes No    
User-Oriented Tasks          
Does the title of the site represent a major task?   1      
Do the topics represent subtasks?   1      
Does the topic order represent the subtask order?   1      
Does each topic have a clearly defined goal?   1      
Is there a procedure for a basic, getting started task?   1      
Does each task have an introduction?   1      
Are the tasks described using action verbs?   1      
Does the graphical user interface emulate the product? 1        
Choose a task - can you complete the task in 10 minutes?   1      
Interactive Tasks          
Are reply forms shorter than one page?   1      
Does the site use QuickTime movies? 1        
Information Updates          
Is the date of the last update indicated?   1      
Is there an automatic update notification mechanism?     1    
Is new information indicated?   1      
User Questions          
Are Frequently Asked Questions (FAQ) included?   1      
For example - How to install the software? 1        
For example - How to start the application? 1        
For example - How to exit from the application? 1        
For example - Where to get help information? 1        
Evaluating the Technical Accuracy N/A Yes No    
Technical Content          
Product names and numbers correct?   1      
Warning and caution notices included and correct? 1        
All outstanding technical issues resolved?   1      
Content technically accurate?   1      
Content tested by technical writer?   1      
Content tested by verification team?     1    
Content approved by product development? 1        
Content approved by product management? 1        
Content approved by product marketing? 1        
Content approved by legal and patents? 1        
Presenting the Information N/A Yes No    
Display Speed (Choose three pages at random)          
Home page displays within 10 seconds with a 33.6 modem?   1      
If not, is there feedback indicating the delay? 1        
Are graphics under 25K in size?   1      
If more than 5 graphics on a page, are they 15k or smaller?   1      
For URL (URI) links, is the final slash included?   1      
Are WIDTH and HEIGHT attributes included on all images?     1    
Are WIDTH and HEIGHT attributes included on all tables?     1    
Are complex tables split into simple tables?     1    
Is there advance notice before downloading large files?   1      
Are thumbnail pictures at least 1 x 2 inches (2.5 x 5.0 cm.)?     1    
Is there at least one link on every page?     1    
Is the color of the link correct?     1    
HTML Format (Choose one page at random)          
Do pages display on small 2 x 3 inch (5.0 x 7.5 cm.) terminals?   1      
Is standard HTML code used?   1      
International Format          
Are international audiences recognized?     1    
Are meeting times international? 1        
Are icons international? 1        
Are metaphors international? 1        
Text Format (Choose three pages at random)          
Text left justified and ragged right?   1      
Format consistent throughout the site?   1      
Figures and tables aligned correctly?   1      
White space used effectively?   1      
Information presented in readable blocks?   1      
Major topics begin on separate pages? 1        
Bad line breaks corrected?   1      
Sentences not continued across pages?   1      
No widowed headings?   1      
No orphans?   1      
Mechanics (Choose five pages at random)          
Spelling correct?   1      
Punctuation correct?   1      
Grammar correct?   1      
Cross-references used only when necessary?   1      
Cross-references to other parts of site use "see"? 1        
Cross-references to other sites use "refer"? 1        
Changes marked accurately with correct revision characters? 1        
Spelling checker runs error free?   1      
Readability checker indicates appropriate level?   1      
List formats appropriate for items listed?   1      
Lists punctuated correctly?   1      
Messages (for example, errors) included and accurate? 1        
Message format correct? 1        
Message style consistent? 1        
Messages as brief as possible? 1        
Trademarks acknowledged correctly?   1      
Trademarks used as adjectives modifying nouns?     1    
Appendixes or References          
References included and correctly placed? 1        
References consist of related but not vital information? 1        
References referred to from topics? 1        
For a 50-page site, can you download a 2-page file?     1    
Do all the text and graphics print?     1    
Does the file print on A4 and US letter size paper?     1    
Summary of Questions N/A Yes No Total  
Finding the Information 0 18 18 36  
Understanding the Information 20 60 4 84  
Supporting User Tasks 6 12 1 19  
Evaluating the Technical Accuracy 5 4 4 13  
Presenting the Information 15 25 11 51  
Total number of questions that you answered. 46 119 38 203  
This checklist has 203 questions in total.          
Calculating the Usability Index N/A Yes No Usability Index (per cent)  
100 x (Total Yes Answers)/(Total Yes + No Answers) 46 119 38 76  

Last Updated on 9/17/98
By Benjamin Keevil