List two user-centred design (UCD) principles the Intelligent Thermostat’s design team may have followed.

Outline one way that the Intelligent Thermostat’s design team would have considered population stereotypes.

Explain how the design of the Intelligent Thermostat’s user interface provides clear feedback and has a low memory burden for its users.

Understanding of users, tasks and the environment / empathy;

involving users design and development / user-centred evaluation;

iterative;

addressing the whole user experience;

multi-disciplinary teams;

inclusive;

Award [1] for listing each UCD principle the thermostat's design team may have followed up to [2 max].

designed the dial to rotate clockwise for “turning the heat up” / anticlockwise for "turning the heat down";
which is the convention for increasing or decreasing (values) for other products;

red indicates an increase in temperature;
blue indicates a decrease in temperature;

the thermostat indicates it is saving energy with a green globe (HeatSmart globe icon);
the colour green is associated with environmentally friendly products (green products);

population stereotypes are responses that are (found to be) widespread in a user population;
adjusting the temperature on other products is also done by turning a dial/knob;

Award [1] for identifying a way that the thermostat's design team might have considered population stereotypes and [1] for a development that way up to [2 max].

Feedback:
the thermostat/interface displays the current and target temperatures;
the screen colour indicates whether the temperature is increased (red) or decreased (blue);
indicating an estimated time to reach target temperature / leaf appears when saving energy;
there is haptic / audible feedback when the dial is turned;

Low memory burden:
no complicated instructions /display is well organized;
self-learning / creates personalized schedule for its users /a simple dial that affords turning;
intuitive, the user does not need to remember how to set the thermostat;

Award [1] for identifying a way how the design of the thermostat's user interface provides clear feedback for its users and [1] for each subsequent development up to [3 max].

Award [1] for identifying a way how the design of the thermostat's user interface provides low memory burden for its users and [1] for each subsequent development up to [3 max].

Mark as [3] + [3].

Even though this question directly asked for listing two UCD principles, a high percentage of candidates struggled to obtain marks. Incorrect responses included usability objectives (mostly learnability and usability), characteristics of good user-product interfaces (mainly simplicity, low memory burden and ease of use). The more able candidates presented excellent responses, including understanding the user, task and environment, making this question a good discriminator.

Candidates who referred to the stimulus material, including Figures 1 and 2, were able to deduce the correct responses. For example, the temperature can be increased by rotating the dial clockwise, or it can be decreased by turning the dial anti-clockwise. Candidates who defined the term population stereotypes were able to obtain one mark.

Instead of focusing on population stereotypes, some candidates outlined target market segments (mainly wealthy users living in smart homes) and geographical locations (mostly referring to temperatures and climates).

As in part (b), the candidates who referred to the annotated Figures 1 and 2 were able to make use of valid points and gain good marks. For example, current and target temperatures and the Nest green leaf.

This is a straightforward question; however, many candidates did not pick up full marks for two reasons. They either did not structure their responses into two distinct paragraphs and/or confused 'feedback' with 'visibility'.