Mark: New page: ==Ten Usability Heuristics== :Jakob Nielsons' 10 Usability Heuristics will be used to evaluate our current system. :'''We will be evaluating what we have added ...

2008-02-15T20:06:40Z

New page: ==Ten Usability Heuristics== :Jakob Nielsons' 10 Usability Heuristics will be used to evaluate our current system. :'''We will be evaluating what we have added ...

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==Ten Usability Heuristics==
:Jakob Nielsons' 10 Usability Heuristics will be used to evaluate our current system.

:'''We will be evaluating what we have added to the system, not the base components'''

:''These are ten general principles for user interface design.''
:''They are called "heuristics" because they are more in the nature of rules of thumb than specific usability guidelines.''

===Visibility of system status===
:''The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.''

:* Any changes to the html document are shown immediately as the user makes them.
:* Mashup elements are displayed in the right side of the application, the user can edit or delete the elements from there.
::- Some elements are not displayed in the html e.g. imported RSS feeds.
:* Advanced users are able to switch between html source and html preview and edit both views (views are consistent).
::- JavaScript code is commented out and uncommented when the document is saved - the user is not told this.
:* JavaScript elements are represented with dummy code (image placeholders with correct dimensions).
:* When the user does one of the following operations they are informed through pop-up boxes.
::- Blank fields for required element attributes.
::- Illegal characters in element names.
::- Duplicate mashup element names.
::- Invalid size dimensions.
:* Potential mistakes that are not identified.
::- Google or Yahoo! Map keys.
::- <strike>Valid RSS URLs (that they are RSS feeds, not webpages).</strike>
::- <strike>YouTube URLs.</strike>
:* User is notified through dialog boxes when there is a problem loading from a RSS feed.
::- Some URLs are corrected (missing http:// is valid).
::- Invalid URL - Instantly.
::- Connection timeout - 5 seconds.
:* Formatting RSS feeds does not show modifications.
::- Removing locations only alerts user to the number of entries deleted.
:::- Removed entries are temporarily printed to the console
::- Approximating locations only alerts user to the number of possible fixes.
:::- Changes are temporarily printed to the console

===Match between system and the real world===
:''The system should speak the users' language, with words, phrases and concepts familiar to the user, rather than system-oriented terms.''
:''Follow real-world conventions, making information appear in a natural and logical order.''

:*RSS Feeds
::- Naming an element is a common action.
::- Users are expected to know ''basic'' computer terms e.g. URL

:*Formatting RSS Feeds
::- Naming an element is a common action.
::- Tool tips are provided to further explain dialog box fields
::- The term 'format' may not be understood by some users.
::- Selecting an RSS feed is intuitive.
::- Format for may not be obvious what it is for until the user tries it a few times.
::*Format for Google Maps
:::- Adding city/country may not be correctly understood as appending.
:::- Preview format shows the user what the add city/country will do.
:::- The city/country textfields are toogled by the check box to aid the users connection between the two.
:::- Optimising may not be understood exactly what that means.
:::- Removing possible invalid entries is self explanatory.
:::- Approximating locations does not guarantee fix all the invalid entries but users may think it does.

:*Google Maps
::- Naming an element is a common action.
::- Tool tips are provided to further explain dialog box fields.
::- Key is needed for the map to work on the users website, they need to already understand this.
::- Selecting an RSS feed to mash with the Google Map may be illogical with feeds that contain no address data.

:*Yahoo! Maps
::- Naming an element is a common action.
::- Tool tips are provided to further explain dialog box fields
::- Application ID is needed and and the user must sign up for this, the ID will only work with the URL.
::- Selecting an RSS feed to mash with the Yahoo Map may be illogical with feeds that contain no address data.

:*YouTube
::- Naming an element is a common action.
::- Entering URL should be obvious for users with some Internet experience

===User control and freedom===
:''Users often choose system functions by mistake and will need a clearly marked "emergency exit" to leave the unwanted state''
:''without having to go through an extended dialogue. Support undo and redo.''

:*Undo/Redo support is supported by base but:
::- Mashup elements can be undone but are not removed from sidebar.
::- Can cause program to crash.
::- Redo seems to work.
::- Deleting mashup elements works better for undoing elements.
::- Deleting a mashup element and undoing the delete replaces code but not actual object in sidebar (causes problems).
::- Editing dialogs are provided for mashup elements to make changes instead of using undo.

===Consistency and standards===
:''Users should not have to wonder whether different words, situations, or actions mean the same thing.''
:''Follow platform conventions.''

:*Mashup elements follow HTML naming conventions where possible.
::- "width" and "height" used for defining map sizes
::- "key" and "id" used for defining map keys and ids
::- "URL" is a commonly used Internet term
::- "name" isn't an HTML term but it has a unambiguous meaning in real life.

===Error prevention===
:''Even better than good error messages is a careful design which prevents a problem from occurring in the first place.''
:''Either eliminate error-prone conditions or check for them and present users with a confirmation option before ''
:''they commit to the action. ''

:*Dialog entry errors
::- Blank fields are checked where needed and user is alerted before action commits.
::- Invalid characters are checked where needed.
::- Duplicate element names are checked.
::- Alphabetic text in width and height field are checked (only allow numerical).
:*URL fetching
::- Invalid URLs are tested on submit and if invalid an error message is displayed before action commits.
::- YouTube URLs are not checked for validity.
::- RSS feeds are not checked for RSS data (ie. XML document with correct tags).
:*User can break code for JavaScript mashup elements by inserting anything before it.

===Recognition rather than recall===
:''Minimize the user's memory load by making objects, actions, and options visible. ''
:''The user should not have to remember information from one part of the dialogue to another.''
:''Instructions for use of the system should be visible or easily retrievable whenever appropriate. ''

:*Only tooltips provided to help user. No help documentation.
:*Preview of RSS formatting when adding city/country helps user see what will happen.
:*No information is needed to be remembered between dialog boxes.
:*Tooltips provided for toolbar icons to help user remember meaning.
:*Mashup elements are shown on the sidebar to show the user what they have created.
::- Mashup element editing boxes provided to remind user what attributes they assigned to each.

===Flexibility and efficiency of use===
:''Accelerators -- unseen by the novice user -- may often speed up the interaction for the expert user ''
:''such that the system can cater to both inexperienced and experienced users. Allow users to tailor frequent actions. ''

:*View source toggle allows the user to switch between HTML preview and HTML source code.
::- Provided by the base program, but still useful to view mashup elements commented code (the final code).
::- Target users of application was more towards novice users.

===Aesthetic and minimalist design===
:''Dialogues should not contain information which is irrelevant or rarely needed. ''
:''Every extra unit of information in a dialogue competes with the relevant units of information and diminishes''
:''their relative visibility. ''

:*RSS feed and YouTube dialogs are kept very simple.
::- No irrelevant information.
:*Google and Yahoo Maps slightly more complicated
::- Width and Height are not essential attributes to display but useful for editing.
:*Formatting RSS is more complicated than rest.
::- Multiple dialog boxes for different formats.
::- Initial dialog simple and no irrelevant info.
::- Google Map formatting is more complex but no irrelevant info.

===Help users recognize, diagnose, and recover from errors===
:''Error messages should be expressed in plain language (no codes), precisely indicate the problem,''
:''and constructively suggest a solution. ''

:*General dialog box error messages inform the user of their mistake
::- Blank field errors do not specify what fields were left blank.
::- Duplicate name errors tell the user what the name was and that it already exists, and to select a new name.
::- Illegal character errors tell the user of the name they used, the illegal characters, and to select a new name.
::- Invalid dimension errors (either non-numerical or negative) tell the user that the size was invalid, but does not specify why.
:*RSS fetching errors displays the reason why it failed
::- "Invalid URL" should be enough information to explain why it failed.
::- "Unable to connect to server" may not be enough information for novice users. They may think their URL is wrong.

===Help and documentation===
:''Even though it is better if the system can be used without documentation, it may be necessary to provide ''
:''help and documentation. Any such information should be easy to search, focused on the user's task,''
:''list concrete steps to be carried out, and not be too large. ''

:*No documentation exists for our system.

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Mark: New page: ==Ten Usability Heuristics== :Jakob Nielsons' 10 Usability Heuristics will be used to evaluate our current system. :'''We will be evaluating what we have added ...