An information booth has been designed for a busy rail

station. This is a premium service only available for

passengers with a special 'Gold Card" that they insert

when they start to use the booth. The booth allows you

to find out information about a journey and to print

tickets. The booth has four buttons beside the screen:

Up$/$Down scroll buttons for selecting from on$-$screen

list, an OK button mainly used for selection and a

Cancel button. The main screen has various options

$($such as holiday offers$),$ but we will focus on journey

planning. To do this the user selects 'new journey'

from the main screen list $($using up$/$down buttons and

OK$),$ then gets a 'Choose destination' screen with

letters A$-$Z on it $($initial letter of destination$).$ The

user selects the letter $($again Up$/$Down buttons and OK$)$

and then gets to a list of stations starting with the

chosen letter from which the destination can be

chosen. Cancel in any of these stages takes you back

to the main screen. Having chosen a destination you

then choose a train time $($again Up$/$Down and OK from a

list$).$ You are then shown an itinerary of the journey

$($showing intermediate stations$)$ from where you can

press Cancel to return to the main menu to look at

other journey options, or press $\text{'}$OK$\text{'}$ for 'one click'

buy and print a ticket $($Gold Card holders are always

Figure TB$1-$ Train Booth Main Screen

Human Computer Interfaces

Lab class #$3$

First Class so you don't get to choose a ticket

type!$).$ question$-$Define slips and mistakes and provide an example of

each while interacting with the train booth