Donovan Lusk
March 11, 2002
CSIS 672 Human Computer Interaction
Professor Manaris

I certify that this report is entirely my own work.

Assignment Number 2

Part 1: Critiquing my Alarm Clock using Norman's design analysis concepts

    Affordances,  are the perceived of an object that suggest how the object is to be used.  The affordances of the alram clock are simple to understand there is the clock face which tells the in terms of minutes, seconds, hours, and alarm time.  There is also a text box with a dialog that tells the user to enter in the time in the correct format.  Also there are two command buttons.  One which tells the status of the alarm either on, or off, and another which is used to quit the application.

    Constraints are the factors (logical, semantic, physical, or cultural) which promote proper actions and prevent erroneous ones.  The clock is fairly standard with hands that denote hour, minute, second, and alarm.  All of different lengths to designate the difference.  It also holds to the cultural standard in America of the hands growing greater in length from hour to minute to second.  The only thing which is a problem is the invitation of the user to type in text in the text box.  I tried to limit this by giving them a format to type before they type.  The command buttons are fairly standard so there should be no major problem with encouraging proper action.

    The Conceptual Model, the mental model which users use to predict how a system works, of my alarm clock is fairly decent.  It is easy to see that you enter the time in the text box.  That pressing the Alarm button turns it on and off, and pressing the quit button exits the application.  The only thing that might be a problem in the conceptual model is that the user might have a problem with the sequencing of events (i.e. that you have to enter the time before you start the Alarm.)

    The mappings, the relationship between controls and effects on a system, is also fairly good.  There are two major buttons which functions which have an effect on the system.  One is the quit application button which is a one to one relationship with the system (i.e. you press the button and the application quits.)  The other button is one which has more a two to one relationship with the system.  The alarm button toggles the alarm to turn off and on..  The input text box where the user puts in the time has no immediate effect on the system.  Only when the alarm button is toggled to on does it have an effect on the system.

    The feedback of how the system works is fairly substantial.  When the alarm button is pressed the background color of the application turns from grey to green, when the alarm goes off there is a beep and the background color turns from green to yellow.  And when the alarm turns off the background color returns to the initial state. If the user enters in the incorrect time then a message box will appear telling them so.

    The visibility of the system is also fairly decent because of the captions on the command buttons and text fields help the user in developing the proper conceptual model of how the system works.

Figure 1:  Start of Alarm Clock Application

Figure 2:  The Alarm has been turned on

Figure 3: The alarm has gone off

Figure 4:  The alarm has been turned off