Heuristic Evaluation

I'm going to write an HCI expert, and using Jakob Neilsens "Ten Usability Heuristics" I'll perform a Heurisitic Evaluation on the ShopNav system. I'll be using the diagrams of the screens that were provided by Baber earlier on in the blog to make comments on.

To make this as least painful as possible I'm going to write down the Neilsens Heurisitics and underneath each heading try and make a comment on HCI point about our software.

Visibility of system status.
The system should always keep users informed about what is going on, through appropriate feedback within reasonable time.
The ShopNav unfortunately fails terribly at Visibility of System Status. The Log on Screen does not mention that is actually logging the person on, but just to insert the store card and then to enter a password. When first logged in the user does not know that they need to search for an item before they can start ShopNav. When the ShopNav is giving directions it does not state what item it is taking the user to.

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.
When directing the user, the ShopNav displays in metric, old people would prefer imperial measurements.
The word 'Begin Route' could cause confusion, but renaming the button to 'Start Shopping' would clarify to old people that start shopping is exactly that.
The text can be too small sometimes for the old people with poor eye sight to read, need a font size changer feature.


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.
The system does allow the user to remove items so if anything does get entered incorrectly it can be removed easily.
The system however does not allow the user to log in because there is no keyboard to enter the pin number!
There is a lot of use of red which is not good because for old people most of them could experience colour blindness which would leave them not seeing much on the screen.

Consistency and standards.
Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions.
Again, the word 'Begin Route' could cause confusion, but renaming the button to 'Start Shopping' would clarify to old people that start shopping is exactly that.
Predictive word like Open Office where if the user types in C, then all the ingredients listed that begin with C appear and it carries on filtering with every key press so that way the user can then select from the final 10 in the list or something of that type of UI.

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.
The final screen shows that before the user is about to pay it does have a confirmation screen that allows them to confirm the price of what they have just bought.

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.
As everything is on screen the user has all of the information to hand which means that they don't have to remember anything.

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.
The more experience the user gets the more they will learn that they can add to their shopping list favourites to save them having to re-enter data into the system. Thanks to the store card the device can also monitor what items the person usually buys and asks them if they would like to add it to the shopping list.

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.
The page that confirms the user is not needed, at this point anyone that has stolen a card and knows the pin number is going to confirm the person. The help button on the user confirmation page is not needed, however a help button on the login pages would be more helpful.

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.
If the store card is inserted incorrectly then the device should display some sort of message

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.
There is no help for the main screen, some interactive help to make the user take the neccessary steps to start the shopping experience, such as searching for an item before hitting 'Begin Route'.